all the great speaker designers were focused on bringing music to the masses, not building ultra expense toys of ego.
Current Trends in multi thousand dollar speakers
Have any of you been paying attention to the current trends in larger multi-woofer speakers that cost multiple thousands of dollars? So that many of you can follow along, i'll use the Legacy Focus 20/20's at $6K, the Piega C8's at $15K and the Aerial 20T's at $23K as points of reference. All of these have been reviewed in Stereophile over the last few months. If you're not familiar with these, all of them are vertical dynamic designs using multiple woofers in vented cabinets.
If you look at the response of of these speakers, they all have very pronounced bass peaks with elevated low frequency plateau's taking place. Of these three, the Legacy's are by far the worst of the bunch. Not only do they diverge from neutrality the most ( +7 dB peak @ 100 Hz ), their elevated bass output or "low frequency plateau" levels out at 40 Hz and at 400 Hz. That is over 3+ octaves of "extra" output that wasn't on the recording. Above 400 Hz, the output levels off with very noticeable rippling slightly above that point in the midrange and multiple large peaks with a dip up in the treble response. Below 40 Hz, the output drops like a rock. The reason that the plateau levels out at 40 Hz is because of the associated sharp roll-off associated with vents below their point of resonance.
To sum things up, this speaker, which Paul Bolin raved about in Stereophile, is anything but "smooth" or "linear" in reproduction. As can be seen in the graphs, there is a very definite "boom & sizzle" type of response taking place here. As a side note, i found that the Legacy Signature III's showed a similar large bass peak centered at appr 100 - 110 Hz, so this would seem to be a consistent design attribute / "house sound" / "family voice" to Legacy speakers.
Moving onto the Piega's, their overall response looks to be measurably smoother than the Legacy's from the midrange on up. As far as bass goes, the Piega's peak occurs at an amplitude of +5 dB's and is centered at appr 85 Hz. Their "bass plateau" is quite wide, actually just as wide as that of the Legacy. Both show the same appr "elevated output" aka "bloat" from about 40 Hz to 400 Hz. Much like the Legacy's, the Piega shows the typical sharp roll-off below 40 Hz due to the output of the vent being out of phase with that of the undamped woofer. Even though both speakers show very similar plateau's and a similar F3 ( -3 dB point ), the Legacy's bass plateau has both a higher peak and a higher average.
Moving up to the $23K price range, we've got the Aerial 20T's. Similar to the Piega's, the Aerial's are reasonably smooth in response from the mids on up with a few low amplitude peaks and dips. Side by side comparisons though, it would appear that the Piega's are a little "flatter".
When it comes to low frequency performance, the Aerial's produced a +5 db peak centered at appr 60 Hz. Of the three speakers mentioned here, the amplitude of the peak is the same of the Piega's ( +5 dB's ), which is much lower ( 66% reduction ) than that of the +7 dB peak of the Legacy's. Even with this 66% reduction of the peak amplitude at resonance compared to the Legacy's, we are still talking about a divurgence of +5 dB's here!!!
As far as the "bass plateau" goes with the 20T's, this speaker is much more linear than either of the above. While the Aerial's also level out at appr 40 Hz and drop like a rock below that point, the upper end of the bass region is MUCH smoother. Whereas the others were contributing added output up to appr 400 Hz, the Aerial's are leveling out at appr 120 Hz or so. In effect, the Aerial's appear to offer the most controlled bass with the least amount of bass colouration. Then again, they are by far the most expensive also.
As far as low frequency extension is concerned, the Aerial's resonance peak is centered the lowest of the three i.e. 60 Hz for the Aerial's vs 85 Hz for the Piega's and 100 Hz for the Legacy. Even though the Aerial's have a resonance that is 25 Hz below that of the Piega's and 40% lower in frequency than the Legacy's, all of their -3 dB points are within a very few Hz of each other. While the graph's aren't completely legible, it appears that the F3 ( -3 dB point ) for all of these speakers are right about 34 - 38 Hz or so. How do such different designs achieve similar F3's? It has to do with the tuning of the vents and the amplitude of the peaks at resonance.
By creating a huge peak at resonance, it takes longer for the amplitude of the signal to fall off. As such, the Legacy's much larger peak at resonance allows it to achieve appr the same F3 on paper that the other designs worked harder to achieve. As such, were the Legacy's designed this way because they like the sound of massive bloat? Were they designed this way so that they could claim a lower F3? Could it be a combo of the two? We'll probably never know.
What does all of this add up to? Judged in comparison to each other and strictly talking about bass linearity, the Aerial looks the best on paper by far. Why just on paper? Because we have to factor in the added gain associated with in-room response. Our ears hear the entire presentation i.e. the speaker and how the speaker loads up / pressurizes & excites the room. As such, what looks the best on paper may not be what you like the most in your room. If you're room is properly set-up, the results on paper and the results in the room should pretty well jive. That is, at least as far as frequency response & linearity go. There are a LOT of other factors going on here though, not to mention personal preference.
What happens if the room isn't properly set up? Compared to anechoic responses, all speakers will have greater output / added extension when placed in an average listening room. While specific speaker placement comes into play in terms of the extension and amount of boost, most rooms will produce maximum ouput somewhere in the 50 - 80 Hz range. Obviously, this varies with the size and shape of the room.
The net effect is that these speakers are going to produce even MORE bass than what they already show in these graphs. Not only are we picking up low frequency output from what is called "room gain" ( "cabin gain" in a vehicle ) by pressurizing the room, we are also going to be exciting the resonances of the room too. All of this adds up to GOBS more "apparent bass". Add in the fact that this bass lacks speed and control* and you've got "bloated, ill-defined thump" running rampant.
Other than that, one has to wonder just how extended the bass response of these designs would be if they didn't have such HUGE peaks? After all, the higher the peak at resonance, the lower the -3 dB point of the speaker appears to be. Do we have to add "bloat" to get extension? How do you get around all of this and still keep good sound? That's easy but it is a completely different subject : )
What i want to know is, what do you folks think about this type of performance at these price levels? Is there anything that we can learn from this? Do we see a specific trend taking place here and in other parts of the audio market? Inquiring minds want to know : ) Sean
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* vented designs all suffer from a lack of transient response, increased ringing, over-shoot and phase problems. In this respect, a well designed port is typically "more linear" than a passive radiator.
If you look at the response of of these speakers, they all have very pronounced bass peaks with elevated low frequency plateau's taking place. Of these three, the Legacy's are by far the worst of the bunch. Not only do they diverge from neutrality the most ( +7 dB peak @ 100 Hz ), their elevated bass output or "low frequency plateau" levels out at 40 Hz and at 400 Hz. That is over 3+ octaves of "extra" output that wasn't on the recording. Above 400 Hz, the output levels off with very noticeable rippling slightly above that point in the midrange and multiple large peaks with a dip up in the treble response. Below 40 Hz, the output drops like a rock. The reason that the plateau levels out at 40 Hz is because of the associated sharp roll-off associated with vents below their point of resonance.
To sum things up, this speaker, which Paul Bolin raved about in Stereophile, is anything but "smooth" or "linear" in reproduction. As can be seen in the graphs, there is a very definite "boom & sizzle" type of response taking place here. As a side note, i found that the Legacy Signature III's showed a similar large bass peak centered at appr 100 - 110 Hz, so this would seem to be a consistent design attribute / "house sound" / "family voice" to Legacy speakers.
Moving onto the Piega's, their overall response looks to be measurably smoother than the Legacy's from the midrange on up. As far as bass goes, the Piega's peak occurs at an amplitude of +5 dB's and is centered at appr 85 Hz. Their "bass plateau" is quite wide, actually just as wide as that of the Legacy. Both show the same appr "elevated output" aka "bloat" from about 40 Hz to 400 Hz. Much like the Legacy's, the Piega shows the typical sharp roll-off below 40 Hz due to the output of the vent being out of phase with that of the undamped woofer. Even though both speakers show very similar plateau's and a similar F3 ( -3 dB point ), the Legacy's bass plateau has both a higher peak and a higher average.
Moving up to the $23K price range, we've got the Aerial 20T's. Similar to the Piega's, the Aerial's are reasonably smooth in response from the mids on up with a few low amplitude peaks and dips. Side by side comparisons though, it would appear that the Piega's are a little "flatter".
When it comes to low frequency performance, the Aerial's produced a +5 db peak centered at appr 60 Hz. Of the three speakers mentioned here, the amplitude of the peak is the same of the Piega's ( +5 dB's ), which is much lower ( 66% reduction ) than that of the +7 dB peak of the Legacy's. Even with this 66% reduction of the peak amplitude at resonance compared to the Legacy's, we are still talking about a divurgence of +5 dB's here!!!
As far as the "bass plateau" goes with the 20T's, this speaker is much more linear than either of the above. While the Aerial's also level out at appr 40 Hz and drop like a rock below that point, the upper end of the bass region is MUCH smoother. Whereas the others were contributing added output up to appr 400 Hz, the Aerial's are leveling out at appr 120 Hz or so. In effect, the Aerial's appear to offer the most controlled bass with the least amount of bass colouration. Then again, they are by far the most expensive also.
As far as low frequency extension is concerned, the Aerial's resonance peak is centered the lowest of the three i.e. 60 Hz for the Aerial's vs 85 Hz for the Piega's and 100 Hz for the Legacy. Even though the Aerial's have a resonance that is 25 Hz below that of the Piega's and 40% lower in frequency than the Legacy's, all of their -3 dB points are within a very few Hz of each other. While the graph's aren't completely legible, it appears that the F3 ( -3 dB point ) for all of these speakers are right about 34 - 38 Hz or so. How do such different designs achieve similar F3's? It has to do with the tuning of the vents and the amplitude of the peaks at resonance.
By creating a huge peak at resonance, it takes longer for the amplitude of the signal to fall off. As such, the Legacy's much larger peak at resonance allows it to achieve appr the same F3 on paper that the other designs worked harder to achieve. As such, were the Legacy's designed this way because they like the sound of massive bloat? Were they designed this way so that they could claim a lower F3? Could it be a combo of the two? We'll probably never know.
What does all of this add up to? Judged in comparison to each other and strictly talking about bass linearity, the Aerial looks the best on paper by far. Why just on paper? Because we have to factor in the added gain associated with in-room response. Our ears hear the entire presentation i.e. the speaker and how the speaker loads up / pressurizes & excites the room. As such, what looks the best on paper may not be what you like the most in your room. If you're room is properly set-up, the results on paper and the results in the room should pretty well jive. That is, at least as far as frequency response & linearity go. There are a LOT of other factors going on here though, not to mention personal preference.
What happens if the room isn't properly set up? Compared to anechoic responses, all speakers will have greater output / added extension when placed in an average listening room. While specific speaker placement comes into play in terms of the extension and amount of boost, most rooms will produce maximum ouput somewhere in the 50 - 80 Hz range. Obviously, this varies with the size and shape of the room.
The net effect is that these speakers are going to produce even MORE bass than what they already show in these graphs. Not only are we picking up low frequency output from what is called "room gain" ( "cabin gain" in a vehicle ) by pressurizing the room, we are also going to be exciting the resonances of the room too. All of this adds up to GOBS more "apparent bass". Add in the fact that this bass lacks speed and control* and you've got "bloated, ill-defined thump" running rampant.
Other than that, one has to wonder just how extended the bass response of these designs would be if they didn't have such HUGE peaks? After all, the higher the peak at resonance, the lower the -3 dB point of the speaker appears to be. Do we have to add "bloat" to get extension? How do you get around all of this and still keep good sound? That's easy but it is a completely different subject : )
What i want to know is, what do you folks think about this type of performance at these price levels? Is there anything that we can learn from this? Do we see a specific trend taking place here and in other parts of the audio market? Inquiring minds want to know : ) Sean
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* vented designs all suffer from a lack of transient response, increased ringing, over-shoot and phase problems. In this respect, a well designed port is typically "more linear" than a passive radiator.
103 responses Add your response
I'm responding here as a private person, and not relating any kind of company philosophy of the company that I work for. This is my own opinion. I think that this type of designing is directly related to marketing and the relative desires of the current crowd of customers. The current music scene is totally dominated with music that is centered around prodigious bass output. People who play this music also want the bass "pumped up". Also, even among audiophiles I have read recently on these forum pages that this current music is quite popular to play on their high-end systems. Classical music is nearly defunct, from a record producer's viewpoint. Jazz is back in the underground scene. What's left? MTV and top 40. Next, I have informally assessed the listening tastes of the Audiogon forum, basically accidentally, when I was discussing the single driver projects that I was undertaking. I found that a very large majority of the Audiogon responders were extremely interested in deep, strong bass response, and would really never consider a project like mine for their own systems. Having heavy bass was more important to them than the other characteristics that I was seeking. This showed me that there are still quite a large contingent of what I would call "bass freaks" in the audiophile community, whether they admit it or not. When it comes to "bass freaks" it is very easy to sell them with the boom and sizzle. I have worked in audio stores and I can tell you that a few extra db in the midbass can sell alot of speakers. They easily fall into the "if some bass is good, then more bass is better" trap. The other very actively-growing segment of the audio market is Home Theater. In Home Theater, accuracy means absolutely nothing. Impact is everything. Big boom means big bucks. So basically, I see these manufacturers responding to the desires of the market. The new customer is purchasing the home equivalent of the "pulsating Nissan" that is next to us at the traffic light in the morning. Now we will have "pulsating homes" in our neighborhoods, as these adolescents grow into higher paying jobs and keep their musical "tastes". These consumers will have combination systems where they will play the MTV music and also watch their movies while the house vibrates. This is considered "cool". When they start to lose their hearing, they will turn it louder to compensate. Can we really blame these manufacturers for following the dictates of the customer base? I think that there is very little market draw being shown to the manufacturers for an accurate product. And the few consumers left that are still demanding it have gray hair.(Although I am somewhat encouraged by some of the younger members here who are showing signs of greatness). There will always be a niche for the listener who wants accuracy. But there are not enough of us to sustain hundreds of high end loudspeaker companies. Some of them are going to turn toward the larger market to get the sales they need to survive. Companies respond to their customer base. The customer base doesn't want accuracy. I'm not happy to be saying that, but I think it is "accurate" to say it. |
Sean, are the response graphs you refer to from JA's measurements? Aren't those in-room and not anechoic? From the year or so I lived with TacT room correction, I know that big bass humps are the norm "in room" and also that a flat response in the bass does not sound "right", just as a flat response in the treble does not sound right (most people prefer a gradual roll-off). What I'm driving at is this: what would you consider admirable performance, Sean? Can you identify a speaker that you and others "like" but that does not exhibit the characteristics you are calling in to question? How does a Thiel stack up, for example? Vandersteen? Quad? Maggie? Dynaudio? I wonder how much of what you are witnessing is a recent trend and how much is and always has been SOP in speaker design. |
Thanks to Sean's post a few months back ( Stereophile confirms ...) I decided to learn how to read the tests of the components and noticed how many of the megabuck components seem to have an engineered sound (re: peaks and dips). The first thing I did when I looked at this months rag was look at the tests of the 20T. Looks like this is another one. I then flipped to the recommended components list. There in Class A was the Hovland Radia. I seem to recall some concern wrt this amp and this was also discussed at length in Sean's (Stereophile confirms...) post. Class A? Go figure. |
I don't know about the speakers mentioned being a new trend but, I personally don't find it as amusing as 2 way speakers at $30,000 plus, or the idea that a single driver speaker can be at all accurate. Well, maybe fairly accurate as long as only one flute is playing. For the vast majority of music the bass line is the building block that supports the rest of the music. You don't have to be a bass freak to want to have a sense of that beat. I also find it amusing when the idea that classical music and jazz are serious music and all others are not. Each in its day was revolutionary and had its critics because it changed what the critic wanted music to be. |
Sean, There is an up side to this, these speakers with thier bass boost aught to sound really good with low level volume - no tone controls or equalizers needed here. :-) On a more serious note, perhaps in a really large room (and I assume some one who buys these really has a large room) the extra boost could be absorbed in the volume of the room - sort of the obverse of small speakers in a big room. Any chance? or is boom just boom? |
Have any of you actually listened to the 20Ts at length? I have, in a suite which was non-ideal, @ CES. Numbers be damned, those are some *fine* sounding speakers. If I had the $ and space, I'd throw down for a pair in a second. One of the best dynamic speakers out there I think. Then again, nearly everything I have heard from Aerial shares this excellence. Are they expensive? Sure. But then again what isn't? I'd take this in a heartbeat over anything from Wilson or piega or legacy or whomever. It will be interesting to see if they start using the ribbon tweet further down the line... -Ed |
There was a big Legacy Focus discussion in this forum a while back. From some of the positive responses for the Legacy, I would have to agree with Sean's opinion that the market is driven by certain "Inaccuracies" in design to please the masses. In the case of the 20T, JA tried to discount the bass peak somewhat with microphone level or something like that. He also noted the slight(and according to the chart-very slight)dip in the upper mids that he atributed it to what the reviewer heard in the response. I have seen much worse responses that JA has not said a negative word about in the testing of other speakers. The 20T was pretty darn flat in the world of speakers today through the mids and highs. The bass was pretty bad for a speaker at this price level. Of course I have never, ever liked ported designs. As Sean says, everyone of them are bumped up at a point to give the "Illusion" of extension so the roll off looks better. I always thought "Hi-end" was about accuracy and truth to the source. I know a lot of people say accuracy isn't the only criteria and that is true. But, if you start with accuracy, add in neutrality and honesty to the source, I think you stand for having a speaker that performs well over a wider range of source material. It won't require so much tuning with cables, power cords, etc. Richard Hardesty dedicated one of his Audio Perfectionist Journals to reading measured speaker performance. It was eye opening at the number of proven inaccurate speakers that were passed for being "Hi-end." I personally believe you must start with accurate reponse across the frequency spectrum and then go from there. If you don't have accurate frequency response, then everything else is a moot point. |
In the imperfect world of speakers, it would be nice to see a speaker at least within + or - 3db over a range of say 40-20k. The closer the speaker is to flat, yes, I believe it has a better chance at being accurate. As I stated, I believe everything must start with a accurate frequency response as possible, then go from there. There is no perfect speaker but look at Vandersteen and Thiel for example. In a chamber, they are pretty dang flat (as the 20T was through the mids and highs.) Both these manufacturers(upper lines especially) hold their specs at + or - 1.5db from the upper 30's to at least 20k(1.2 in the case of the 5A.) In the case of the Vandersteen (and probably the Theil), they are matched within + or - .5db to each other or less. The point here is, these manufacturer's have a proven accurate speaker(in todays world of accurate) at a much lower price point(especially in the case of Vandersteen.) You may not (and don't have to) like their sound, but they are accurate by any standard and built superbly to boot. Look at the Legacy Focus 20/20. Do you feel + or - 10db to be accurate even if you think the speaker sounds good? |
Sean, this is the second time I've read about you going on in length about your feelings of Legacy. I could think of a couple companies I would like to say the same about, but why the public bashing more than once? Your beginning paragraph that states the "Legacy is by far the worst of the bunch". Doesn't it make sense, after all, it is by far the cheapest of the bunch. |
i think you're comparing apples and oranges and thinking they should taste the same.you can't compare these 3 speakers and come to a conclusion that one is best.if you want to compare the ariel 20t with a piega model use the c-10 ltd rather then the c-8 ltd.my guess is your conclusion will be different. |
Twl: I think that there is a BIG difference between poor tonal balance and proper timbre. Tonal balance has to do with frequency response linearity. Timbre has to do with pitch, harmonic structure and transient response. Judging from what the market is buying and manufacturers are selling, it doesn't seem as if either are important. Jrd: For some manufacturers, the goal of achieving utmost accuracy and purity of signal leads towards price no object components. Other manufacturers ride the price escalation train and simply raise their prices without the associated effort or increase in performance. To be fair, it takes time, money and research to build the best product that you can. To expect phenomenal results at very low costs is simply day-dreaming. On the other hand, paying tall cash without obtaining some type of performance returns demonstrates a complete lack of value. Drubin: For your reference on each review mentioned: Fig 5 p 80 Legacy review states: "Legacy Focus 20/20, anechoic response on ribbon-tweeter axis at 50".... As a side note, the HUGE bass peak measured here would be even more prominent if sitting off axis of the tweeters. Given that the tweeters are 45" above floor level and an MTM array drastically limits vertical dispersion, one could expect an even boomier tonal balance. The phenomenal peaks at ( +5 dB's @ 6K and +8 dB's @ 12K ) may help balance this out though due to psycho-acoustics. Fig 4 p 114 Piega C8 LTD review states "anechoic response on tweeter axis at 50". Once again, as one moves further off axis of the tweeter, either vertically or horizontally, bass response will seem to become stronger due to treble response softening. At least with the Piega, the tweeter appears to be closer to the average seated listening height. Compared to the Legacy which was reviewed in the same issue, Piega's would therefore sound "brighter" ( or "leaner" depending on perspective ) than the Legacy's with their tweeter positioned off axis. You have to compare apples to apples. The Aerial review fig 5 p 137 states "anechoic response on tweeter axis at 50"... Given the height and position of the tweeter in this speaker, the perceived tonal balance might soften on top a bit compared to the Piega but would also be "hotter" than that of the Legacy. That's because the tweeter is centered between the two different speakers in terms of listening height. As far as your comments about "non-humped" bass NOT sounding "right", that's because people aren't used to natural sound and don't listen to acoustically performed music. They have been "brainwashed" into thinking that elevated bass response, poor transient response and swapping more "apparent" bass aka "bloat" for true extension to be "normal" and how things should sound. As i've commented before, most people hear but they don't know how or what to listen for. Part of this could be personal preference, part of it could be a lack of familiarity with how instruments really sound. As far as naming specific speakers go, that would be hard to do, especially in stock form. Can you point me to a well designed speaker that offers coherent arrival of the sound, linear in frequency response without major abberations, offers minimal ringing at any given frequency while producing good bass extension? Quite honestly, i can't think of a single modern day product that meets that criteria. Then again, finding one that was ever produced would still be tough : ) Nutella: Kudo's to you. Keep reading and learning. you'll end up with a better system and a lot more money in your pocket. Those that can't figure things out for themselves and get their information from the "candyman", who claims that sugar and starch don't cause tooth decay, are doomed to deal with a lot of "rot". Agaffer: There are single driver speakers that produce deep and powerful bass, they just aren't made anymore. As to being "accurate", they can do that too, so long as spl's aren't climbing. There's much to be said for a speaker that produces the proper timbre with good dimensionality. If you don't know what timbre is, read my response to Twl. Ed: Compared to many of the other offerings available, i would agree with you. That is, the Aerial probably is a better sounding speaker than most of the stuff out there. Given that i've never even heard these, i can tell that they have more design effort into them than many others. Reading the test results and knowing how to interpret them, it isn't hard to judge their over-all linearity, phase response, dispersion characteristics, etc... as being as good or better than much of the "high dollar" competition. Then again, there is obviously a LOT of room for improvement in this design, so what does that tell you? It tells me that either it costs more to build a great speaker than $23K will buy or the manufacturers aren't doing their homework. Bigtee: I think that you are going to join me and a few others in the "outcasts of the audio society" if you keep saying things like this. Drubin: Yes, linear response is the building block of both a pleasent and accurate system. If linearity doesn't matter, you might as well start using your old 10 band graphic EQ to colour the response to your personal tastes. After all, what's the difference in 5 - 8 dB's boost or cut if done at the speaker or at the EQ??? Bigtee: Thiel's and Vandy's both have problems with bass response linearity. Passive's are slower than ports in terms of transient response. Other than that, my one major question is: Why don't speaker designers take into account the accepted "facts" of a normal installation and incorporate these attributes into their designs? Room gain, seated listening height, reflections, etc... along with linearity, transient response, etc... all seem to be "foreign words" to most of these folks. Sean > |
The Vandersteen 2's and 3's use a design where the enclosure is sealed with an active acoustic coupler below 35hz which does act somewhat like a passive radiator reacting to the front woofer. However, since the drivers are active, it gives you the best of both worlds. I have not found the Vandersteen bass to not be linear. Maybe I'm miss understanding the term linear. With this setup, the bass goes smoothly from its upper range to a roll off around the 30-35 hz area. Compared to other speakers in this price range, it's pretty darn good. I also think it performs better than ported speakers. Its transient response may not be the worlds best but for the price, it will compete with anything in its class. Of course I have gotten around this somewhat by using a pair of Vandersteen subs and rolling out the bass below 80hz. The model 5 and 5A are not passive at all using a powered subwoofer. When set up properly, they offer extremely powerful, articulate and clean bass. I know of no other speaker that comes close to the performance of the 5/5A's performance at anywhere close to the price. It is amazing at the performance Vandersteen can offer for these prices in both design and quality. It is certainly more difficult to design a time coherent and acoustically correct phase speaker. I think the measured and published specifications speak for themselves for his speakers compared to any price but more especially at what they can be had for. My point is back to the original statement, why is it that costs can be so high for a speaker that doesn't perform as well or any better than a speaker selling for $10000 less. It has got to make you wonder. |
One thing that's overlooked when analyzing speaker frequency response graphs is that they don't tell the complete story. It is assumed that a "flat" response oozes performance but that is only true in a laboratory environment. In the listening world: a box speaker has two cabinets - one behind the driver (the enclosure) and one in front of the driver (the room). The room effect is very similar to that of the enclosure - that is, it affects the frequency response and other parameters the way that the enclosure does only to a less extent due to the increased volume. So when a crossover is designed based on the driver T/S parameters, enclosure volume, port size, etc, the attempt is to not only optimize the frequency response but phase, impedance, incursion, acoustic power etc. When all is well and done, these are measured without the effects of the room (anechoic chamber) and presented for all to see. But this doesn't really say much about the sound in an enclosed room. The room itself will throw these carefully crafted measurements out the window. That's when the listening tests come in. By tweaking this cap here and that resistor there, a best sound is determined and the stuff is packed and marketed. But after the tweaking process, the original perfomance curves are different than the original design. The in-room listening process forced it to depart from "flat". So what? If it sounds $15k better than the other stuff, well... It all boils down to how it sounds. Measurements and specs just confuse things with respect to speakers, IMO. |
For the most part audiophile oriented speakers have always had "tailored" responses. When compared to to accurate studio type monitors the typical audiophile speaker provide excess warmth, image depth and various forms of treble emphasis. Is the issue presented above really a question of someone simply not liking the specific tailoring of a recent group of speakers? The response curves presented in Stereophile are not actually speaker response curves. John Atkinson performs various measurements 1 meter at the tweeter level and the graphs derived are an anechoic average across a 30 degree vertical and 30 degree horizontal window with a "complex sum of the nearfield responses (taking into account acoustic phase and distance from the nominal farfield point) plotted below 300Hz." It's not altogether clear that this type of measurement corresponds accurately to what the speaker will sound like in an appropriate room. It's interesting that Stereophile did not provide the one-third octave average in room response for any of these speaker. |
Mejames: I have a LOT of respect for John Dunlavy even though i disagree with his point of view on the audibility of wire / cable changes in a system. Having said that, there are certain parts of his speaker designs that needed help. He acknowledged this when he upgraded / re-designed the SC 4's to the 4A's. While the 4A was "technically more correct", it seems like he fixed a few problems and introduced new ones. I think that a lot of the new problems were related to the new crossover design, which was far more complex. Parts heavy crossovers reduce the amount of control that the amplifier has over the drivers ( more "middle men" to deal with ) and reduce the detail that a speaker is capable of. My Brother's actively crossed quad-amped system is similar in design theory to that of the Dunlavy's. It is both more advanced yet much simpler in nature. Lancel2000: You can't stop the bleeding once you've already got a wound. You can try to minimize the damages though, but various methods may introduce their own side-effects. Depending on the severity of the wound and the approach taken to try and "band-aid" it, the results and side-effects will vary. Bigtee: I'm not quite certain how Vandersteen is working his "active coupler's", but they are some type of "fancy" passive radiator. I will give Richard credit though as he is a far more realistic designer than most speaker "engineers". He at least provides the ability to fine tune the electro-mechanical properties in his top of the line speaker and in the active subs. On top of that, he also uses more internal damping material than most vented designs, reducing internal reflections and reducing cabinet resonances. He needs to work on his tweeters though as there is something funny going on there. Most amps have a hard time loading into them, causing the top end to both soften in quality and fall off in output. Gs: You are trying to introduce products designed for the "real world" here, but doing so in a back-handed manner that is not nearly as complimentary as it should be. From what i can tell, you slapped the people that you were trying to compliment and made a case against that type of product for those that seek "musical accuracy". You basically said that if the device measured more non-linear in actual use after hand-tweaking but sounded "good", that was acceptable. As far as i knew, the whole idea behind hand tweaking / customizing is to improve linearity, which improves the sound also, under the actual operating conditions. It was not meant to introduce further signal degradation or specific colourizations. Then again, i want to hear what is on the recording, not have all the recordings sound the same or cater to a specific presentation. Maybe we have different goals. Other than that, I'm all for products that are designed to work with their environment. I just don't know where they are or who makes them. To me, such a product is the MOST "technically correct". The only problem with such an approach is that to market such a product and have the end user achieve the same results in their home, the product has to be operated within the boundaries of the original design parameters. Operating said product out of the design parameters basically negates all of the research and special attributes that went into making it what it is. How many people ever read their product manuals? How many people actually follow detailed installation instructions? Not many from what i can tell. Between the lack of familiarity with the product, poorly written manuals and / or manufacturers that don't know how to design properly, most people never experience the joys that a good system that is PROPERLY installed can bring them. For that matter, most of the "professional installations" that i've seen were ALL wrong. With that in mind, how many "civilians" do you think can get it right??? As such, the manufacturer / sales rep / dealer / installer has to know the specifics of how a product is to be used and the end-user has to follow those directions. If one likes a product but it can't be used as intended in their specific installation, it should be avoided. Placing a speaker out in the room that was designed to be placed near the wall ( or vice-versa ) will negate any of the "real world" benefits of that design. Not only will such a product probably deliver far poorer performance, there will be quite a few side effects too. Hand tweaked / room optimized designs are only as effective as implimented. Onhwy61: Good points, especially about the one-third octave averaging graphs. My guess is that the results weren't very flattering, hence their lack of inclusion. Sean > |
I find it interesting the great importance assigned by many to linearity when in fact the human ear is anything but linear. In chapter 3 of the Master Handbook of Acoustics attention is given to the effect of the ear canal on incoming sound waves. Sound pressure meters do not measure the spl at the eardrum. They measure the spl at the meter itself. I suspect that our desire to measure everything in our physical environment has hastily overlooked certain as yet unquantified psychoacoustic realities. It seems to me that most forms of human language and vocabulary have yet to evolve such that each of us can converse understandably about what we hear. Perhaps one could be characterized as a bass nut which said description I think would be the audio equivalent of a racial stereotype or one could be characterized as an individual who assigned great or at least equivalent importance to the bass or percussion musicians of any given musical event. In short, I personally have far more faith in a large group of people who are familiar with live music calling a system realistic sounding than I do a set of scientific measurements. |
Sean, I think your paragraph on setup is probably the most important bit of information to come from this thread. I understood this many years ago when I first got into Vandersteen. These speakers are a pain in the butt to get set up correctly and it has taken me years to really figure it out. Once set up, they are pretty impressive. As for your statement on high frequency roll-off and drive problems, I don't know about that. Any test I have seen shows them flat out to past 20K. I have used special measuring instruments and a signal generator in my room and as mine sit, they are pretty flat to 20k. If you are refering to the Vandersteens sounding rolled, well that's another story. It is partly the design of the speaker. Since the tweeters acoustic output arrives with the mids, they don't throw a bright sound at you(although with the wrong electronics, I have heard mine bright) Also, setup is so important and Richards suggestions are just that, suggestions. I have had many speakers through my room and the Vandersteen's do not sound rolled in comparison to any of them in this setting. I have found them articulate, with pristine highs. If I had a gripe, it would probably be more in the midrange arena. If you ever make it to the Charleston area here in SC, you're more than welcome to stop by. We have good seafood and a beautiful city. I think you could be pleasantly surprised on how a Vandersteen can really sound as a bi-product of years of fine tuning a system.(Of course along the way, I have thought of dumping the whole thing and buying a new boat!) Right now, I'm disappointed in high end audio. It has lost something along the way. I've been at this for over 35 years and I've never been more disappointed with much of the new entries that are coming out. Everytime a new product comes out, everyone jumps on the bandwagon only to dismiss it a few months down the road for the latest and greatest. People can argue against accuracy and argue about this and that. However, I have never heard an accurate speaker(relatively speaking) that didn't sound decent. I guess in the process, the designer pays attention to the other stuff also. With all the variables in audio, which ones do we want to take as truth. I mean, my kids think their car stereos are the end of the reproduction chain. Hey, it sounds good to them. So, I guess it fits into the high end---it sounds good. So what if it has a 15db boost at 80hz. And this is what I reading from some of the posters here. High end redefined! We have to start somewhere and I feel accurate acoustical output is it. I think it is better to tune the room than tune the speaker. |
I think that Twl is generally correct except that he thinks that bass is not important. It is, but it should be reproduced correctly. Single driver is not a solution at present, in the future maybe. For a small or medium size room 2 driver design is usually the best compromise, in my opinion. I will leave the panels alone, that's different approach.I also believe that both room and speakers need to be tuned to give the best result. How to achieve it in every case? Simple. Custom work. |
A few random thoughts: Stereophile reviews of $20K-$30K loudspeakers are about as important to me as Flying magazine reviews of Learjets. In my engineering work we consider the "baseline" design as "something from which to deviate". I think that flat frequency response is a similar situation. If the drivers/crossover/enclosure has a lot of peaks and dips in the response, it will be difficult to tune it to sound good. So I would say that a speaker with flat response is a technically well-designed product, but perhaps has not been given that final step of artistic (non-technical) tuning. As far as the high end goes, in my system I find that my MG1.6 sound good to my ears (which are vintage units) but I did install 1.5 ohm tweeter padding resistors (worth 3dB) so as to avoid frequent use of my tone control. I have no idea how "flat" the high end is. With regard to the low frequency range, I have an elaborate (6 diver) subwoofer system, and an Audio Control Richter Scale 1/3 octave equalizer/analyser. I can make it flat down to near 20 Hz. It's an interesting technical tour-de-force, but music sounds better when I permit a substantial boost of the kind that Sean decries in his comment. Spectral balance of music is highly subjective. Using classical as an example orchestration and conductor preference varies greatly. Does the performance highlight the cellos or the violins? Musical instruments themselves vary greatly. Different cellos sound different. And then there is the recording engineer, twisting his dials to suit his subjective tastes. And when all this is said and done, I still have my tone controls to play with. Other characteristics of loudspeaker are, I think, much more important. In very highly regarded speakers, I still hear too much IM distortion. Harmonic distortion is hard to distinguish from the music, which includes harmonics, but IM sticks out like a sore thumb. IM distortion is what makes a speaker sound like a speaker. I have a fond memory of "full range" drivers, because when I began this hobby that was what almost everyone used. However, the way that a full range driver gets its HF ability is cone "breakup", where the center part of the cone is vibrating differently from the outer part. "Whizzer" cones take cone breakup to a greater extent. Somehow the idea of all this uncontrolled vibration going on in the cone turns me off. Some full range drivers can sound pretty good, but this is an art, like building a violin, and characteristics of such a driver will change as the cone materials age. If you want to have "coherency" of HF and LF, I think that a coaxial driver is a better approach. |
No, using multiple woofers is not the culprit. Poor design skills, using too small of a cabinet for the given drivers and not enough internal damping material inside the cabinets themselves are the culprits. Larger cabinets produce resonance at a lower frequency, hence offering more linear bass extension. Poor tuning of the ports / improper bass alignment is what produces the single huge peak. The very wide bass plateau's are caused by not using enough damping material inside the cabinet. Just further evidence that too many "manufacturers" are using "computer software" to design their products. They do this because they don't really know how to build & design a speaker on their own, let alone tweak the results that the computer program itself provided. As a side note, most people think that vented designs should use physically smaller cabinets than sealed designs. That is exactly the opposite of the truth in most cases. The general public has been lead to believe this because many companies use vents in very small speakers. This was not to give more bass extension so much as it was to "fool you" into thinking the speaker had better bass. What they did is give you more apparent bass with higher sensitivity i.e. quantity over quality. The whole reason that Edgar Villchur and Henry Kloss designed the acoustic suspension speaker was that it offered the best bass response characteristics that one could achieve in a smaller box. At the time that they were designing the Acoustic Suspension speaker, other designs used some type of vent or open baffle and the cabinet had to be HUGE to get any kind of deep bass out of it. Not only do acoustic suspension speakers provide better transient response, they also offer a slower roll-off below the point of resonance. As such, a vented design that resonates at 45 Hz will be -24 dB down at 22.5 Hz ( one octave ). A sealed design that resonates at 50 Hz ( vents always look more impressive on paper ) is only -12 dB down at 25 Hz. You tell me which speaker has better extension in the real world. Then factor in transient response, which sealed speakers do better. Now ask yourself why a manufacturer would want to use a vent and you'll figure it out soon enough. They are cheaper to build, cheaper to ship, offer more apparent bass and take less power to pressurize the room. The bottom line is more profit, more bass, more sales. With such a situation, how can they lose? There is only one way that they could. So long as they keep the consumer in the dark and hope that they never become educated or learn how and what to listen for, they'll keep racking up sales by pushing garbage out the door. High profit garbage at that. Sean > |
Long -- sorry. Holzhauer sez: "I ... have far more faith in a large group of people who are familiar with live music calling a system realistic sounding than I do a set of scientific measurements." Agreed -- but I think you'd be VERY surprised at how CLOSELY measurements of speaker response can reflect the comments of this "large group of people". Ever since I've been dabbling at diy & measuring speakers, I have been astounded at this. Sean notes: "Other than that, I'm all for products that are designed to work with their environment." Problem is, which PARTICULAR environment -- i.e. speakers tuned to my present room will not sound as good in another room OR even my next room. So anechoic is the norm (for manufacturers who can AFFORD a dedicated anechoic room). ------- On to contemporary, giga$$ passive speakers. I wonder if what Sean is asking for (i.e. good, accurate low end extension) is really possible in a commercial passive set-up? First, I notice that the mid-to-high extension and response have been addressed quite well... at a cost, of course. Many expensive speakers offer supersonic response, well into the 30kHz -- some (Kharma, etc) going up to 80kHz with the Thiel & partner hard ceramic (diamond) tweets. Some (say, many British products) are tuned to a "BBC dip" of a few db towards the 3kHz point. This makes the sound more "pleasant" to the ear. Many (very expensive) offerings have succeeded in offering a seamless response in the critical midrange -- even more than that (say 100 -- 10kHz) However, I wonder of there are ANY passive speakers that can offer a bass response to match their upper extension. I really wonder whether it is POSSIBLE to do this WITHOUT a multi-amped set-up where the filter is BEHIND the amps. Eldatford, Sean, many others using this kind of set-up are a case in point. I mean, imagine the SIZE of, say, a closed box q=0,7 speaker with f3 at ~25Hz and the amplification required to MOVE the thing!! Worse, what's the market for this thing??? If you look at the Canadian NRC/Soundstage measurements here you will notice more of what Sean relates in his original post -- i.e. many (most) speakers rolling off as of ~60Hz. Ultimately, I respectfully submit that: 1) choose the speakers by concentrating on timbre, tonality, (and ultimately phase) characteristics in the range down to ~60Hz MAX. 2) If you find that you need extra dbs in the low end spl, add another stereo speaker system (i.e. subwoofers) powered by another amp, for the last two octaves. Make those drivers 15" or better. Pray that the wife won't cringe! Cheers |
Ah Sean, you have hit on one of my true sensibilities, tuning speakers to sound like they have more bass! I guess I should really understand why they do it, but like you, I don't like it much at all. A manufacturer often tunes the bass so that we mere mortals think, "Wow, that speaker has really great bass" or "It sounds a lot bigger than it really is". Of course, one could argue that this speaker will also sound richer at lower listening levels. However, once you start to goose the volume up, bad things begin to happen. In my experience, the issue will manifest itself in either port noise(which I somehow have become quite sensitive to of late) or congestion (where things just seem to back up and more power results in mostly more distortion - which many people actually seem to enjoy or mistake for volume). I can go into examples of speakers which suffer from each malady to illustrate my point, but that often seems to inflame. Of course, I can also list loudspeakers which eschew this practice. Over time, they have earned my appreciation and respect. The point of speaker manufacturers reacting to public pressure to produce the kind of sound that customers demand is an excellent one which TWL among other makes. However, we in the high end community are supposed to be different. We take pride in thinking we know what music should sound like. However, one point which Sean's post makes quite well is that just like the stereo shops of the 70s, boom and sizzle is the way to sell a speaker. That seems to hold true regardless of price. If we weren't buying them, they wouldn't be making them. |
If we are seeking the root cause of the "problem" I think it is sending out a 7 inch woofer to do a 15" woofer's job. Small woofers have good midbass and midrange performance, which can be a weakness of larger drivers, and this, along with the holy grail of imaging seems to be what is in vogue for speakers today. Using such small woofers, manufacturers must drive them hard, and resonantly tune their enclosures to get acceptable (but not to Sean) LF response. I like the approach of many large drivers for the SW frequency range, so that none of them needs to work hard. Upper bass and midrange can then be handled by appropriately smaller drivers (or in my case, by Maggies). |
Interesting discussion with many valid points, but has anyone actually heard any of the 3 speakers in question? It's raises eyebrows that these speakers may measure poorly (and the Stereophile graphs are not the final word in how these speakers measure in an appropriately sized room), but the ultimate question is how they sound in real life situations. Do they sound bass heavy? |
Look at the theoretical frequency response curves vs critical dampness. Look at the frequency response curves that were recorded in Stereophile reviews and it looks like they are critically damped at or higher than 0.7. If you go to R. Harley's book on high end audio you will see a few pages describing these effects. The argument being that a critcally damped speaker of 0.5 has better bass transient response but maybe a leaner sound and no hump. Where something like a critcal damped speaker with a function of 1.0 gives that nice hump at 80-120hz. Just a thought. |
Hopefully, some of you folks that are interested in learning will be able to follow along with this. To try and put things in understandable terms, the "Q" of a speaker relates to the amount of damping at resonance. The speaker with a lower Q has more damping. It is this damping that keeps the speaker from going into oscillation. Higher Q designs go into oscillation both easier and to a greater extent once excited. This is what causes both the higher output at resonance ( bass peaks ) and the poorer transient response. After all, if the driver itself is undamped and resonating, there is nothing to stop it from ringing. Ringing equates to poorer transient response and lack of definition. One note "blurs" into the next. Think of a low Q speaker as having a lower noise floor i.e. more "inter-transient silence". A bass note will hit, stop on a dime and then play the next note. Once you hear such a system, the difference in definition, separation of notes and "speed" is quite apparent. Having said that, most people that hear a sealed speaker with a Q of .5 or so think it sounds noticeably lean i.e. just like Clara Peller of Wendy's hamburger fame yelling "WHERE'S THE BASS" : ) For sake of reference, Dunlavy shot for a Q of .5 in his larger designs. AR aka Acoustic Research also used a Q of .5 in some of their larger models "way back when". If you do some research, you'll find that AR and Dunlavy shared many similar design philosophies. A Q of .7 in a sealed design is much more common and still provides pretty reasonable damping / transient response. This gives you more apparent bass AND more extension without getting "sloppy". Just like the "bass hump" that designers / engineers are building into the ported speakers, the reduced amount of damping at resonance ( higher Q ) allows the speaker to look better on paper i.e. slightly lower F3. Personally, this is the highest Q that i find acceptable in a sealed design. As a side note, .7 to .8 is the "marketable" sound of a sealed speaker i.e. it still has enough bass to attract the "thump happy" folks that buy vented systems while retaining good enough transient response to not annoy those folks that crave "accuracy". With all of that in mind, one has to take certain factors into consideration when designing a speaker. First of all, the lower Q really DOES have better transient response. Some people find this to sound somewhat "dry" though as the lack of ringing seems to cut the notes short. The truth is that they are just too used to listening to "slop" and need to get re-educated ( both ears and brain ) on the subject. Given that my Father has Legacies and i just went through and re-designed them, i'm going through this with him right now. He can hear that the bass has GOBS more speed and articulation, but he still thinks it sounds "lean". In comparison to the bloat that he had before, it does : ) On top of all of that, the Q of a system changes as the driver heats up. When throttling a speaker system, it would not be uncommon for the Q to start at .5 and climb up to a Q of .6 or possibly even a .7 or so. As such, speakers that start off with a .7 are now at a .8, .9 or possibly a 1.0 under heavy load. While this may lend more "drive" the music, it is also sloppier and less accurate. Then again, if you've had a few "liquid refreshments", you're probably less apt to notice this : ) The "temperature fluctuation" and "Q variance" are a few reasons why some designers shoot for a very low Q to start off with. Using this approach, the speaker system offers very fast / accurate transient response at low to medium levels. When pushed harder, the Q does climb, but not high enough to completely destroy the "speed" & "definition" that the listener is used to at lower volumes. If one started with a Q of .7 and ended up at 1.0 when hitting the throttle, the difference in "bloat" would be more apparent as transient response is now noticeably poorer than if one went from a Q of .5 up to a Q of .7 under load. There are some speaker designs that utilize VERY high Q's. If i can remember correctly, the big Carver ribbons had a Q of well over 2 !!! While this seems phenomenally high ( it is ), it isn't quite as high as one might think in this specific application. If this were a more "normal" design with the woofers mounted in a box rather than free air, the bass would be attrocious. Due to being free air or "dipolar" in radiation, you get a LOT more cancellation from out of phase reflections. By introducing a HUGE peak at resonance, the bass that would normally be lost / thinned out due to cancellation is somewhat recovered due to having such a big peak. To anyone that has never heard the larger versions of these speakers, they are known for having over-powering bass. Not only is there too much bass, but what is there lacks definition and speed. If one were to take this design and substitute drivers with a lower Q, they would end up with a much better product. If this sounds like some speakers that are currently being marketed, just remember, they didn't copy the Carver's, the Carver's simply served as "inspiration" : ) Drubin: Very few companies market sealed designs. Even if the designer has enough integrity to market a great product, most reviewers and end users wouldn't know what to do with an accurate speaker. Probably the first thing that they would do was complain that it sounded "lean" because they are used to listening to "indistinct bloated thump". Sean > *At one point in time, AR had over 32% of the loudspeaker market and only sold sealed designs. To put that into perspective, Bose is currently the largest speaker manufacturer in the world. As far as sales go, Bose products garner appr 13% of all speaker sales made. Granted, there are more people buying speakers today than ever before, but that should tell you how "powerful" AR was in the marketplace at their peak. As a side note, AR "invented" acoustic suspension ( sealed & stuffed ) designs AND they also invented the dome driver ( tweeters and mids ). As a general rule, the average dome is FAR more "linear" or "accurate" than the average cone driver. As has been previously noted though, linearity and accuracy went out the door a long time ago, so AR products fell out of favor. Not coincidentally, this took place at the same appr time that vented designs started to flood the market. Once again, quantity of sound won out over quality of sound. Having said that, the influence of some specific AR designs are highly evident in several different product lines. Believe it or not, one can show direct correlations between specific AR designs and some of Bill Dudleston's Legacy designs. The difference here is that AR actually used cabinets that were of suitable size for their multiple woofers and retained the sealed design. |
In my experience, virtually all the points made above are pretty right on. However, I would like note two reasons for the skewed (measurable and/or audible) tone balances. I believe most tone-balance/cabinet-tuning decisions are made to offset the audible effects of a speaker having serious amounts of phase shift at every frequency, high to low. Bass boost, no matter how obtained, is most often used to offset the sharp/overly-aggessive sound of a phase-leading treble (or equivalent woofer time lag). Doesn't happen if designers listen to live music often. You also see designers turn down the tweeter, and "pull apart" the tweeter/mid crossover point to introduce a dip (measured) but "not" audible. Until you hear it after 30 CDs... especially the ones that "work out" the crossover range. The other factor is the type of room- large and open, vs medium and damped, etc. East coast/West coast homes... Fortunately, in hi-end, most expensive speakers can be designed for use in moderately damped rooms of 300 to 700 sq ft with listening distances between 8 and 15 feet, for a seated listener on an average sofa. That's a useful set of constraints, in my experience. When the phase shift in a speaker is reduced to just a very few degrees of fluctuation thru the main part of the audio band, it becomes MUCH easier to A) set the amplitude response to sound flat and to measure flat, and B) for the speaker's tone balance to remain similar in a wide range of positions. I think it's important to try and state why something "happens". Above it may seem like I know what I'm talking about. But can I justify A) & B) very simply? Yes- For A) set the amplitude response flat: Having excellent phase accuracy/time coherence between drivers means that all the amplitude peaks and troughs from woofer and tweeter line up over each other. You get the amplitude you put in, since nothing is cancelling. No matter what the test tone or the music. When they are out of phase, what you measure depends on HOW you measure- the type of test signal, particularly. What you hear depends on the tone range and the complexity of the music. For B) less room dependent: Since reducing phase shift results in a more temporally compact, succinct presentation of the music's dynamics and tones, then you can hear the speakers more clearly apart from the room's echo. Which is an echo field also then less cluttered. If a speaker has gross phase shift from the mid down to the bass, as most of the ones discussed above do, it is usually a lag on the order of many milliseconds- which is the distance to the wall behind, or farther. With ringing at the crossover point. Which all sound like room problems because of the long time delays. "I just moved them out 1/2" and the bass got much better!" It did- but only because of a particular interaction with the room, and your location, exaggerated by that woofer's trailing output. Slow rhythm is the clue it is not the room. My comments here are primarily directed at dynamic speaker designs. One factor I should mention, which frankly is just as important to "coming up with" an OK tone balance is the drivers: Multiple mids and one tweeter change tone balance w.r.t each other, as you move away. Multiple tweeters and multiple mids change relative tone balance as you move away. So do multiple woofers vs a single mid. Physics and measurements support this. Apparently, most designers ignore this, looking for some other performance aspect from using multiple drivers. They should tell you the design distance/listener height. Hope this is useful info. Nice thread. Do all of you see a trend? Egads! That would indicate speaker design is a mature technology. No way. Best, Roy Green Mountain Audio |
I am so glad Sean has brought this up. My two cents on the topic are as follows: Most Audiophiles get obssessed with the notion of high dollar speakers in the pursuit of sonic perfection. This is why it is without a doubt the most traded and talked about component. It is a combination of sonic qualities and aesthetics. What I find most interesting about this group is that compromise in tolerated more as the price of speakers increase. It is truly an odd relationship but one I have witnessed countless times (both among Audiophile freinds and the press). As Sean points out, this is certainly the case with so called "neutral" speakers costing obscene amounts of money ($25K could be used for many more worthwhile purposes than buying loudspeakers!!). There is really something wrong with the audiophile community when in indivduals are paying crazy prices and are still upgrading and swapping, etc. As usual many getting too involved in listening to the system and NOT the music (this is in fact now an integral part of the hobby - a real shame). For those of you paying these prices for speakers my advice is 1) buy more music!! Spend a lot less on the speakers (you can get great sound for $2000!); 2)ask yourself why Audio magazines and stores do NOT do blind testing? I think we would find widely varying results that would favor less than orthodox choices. In any event, I think many kilo buck audiophiles (of which I was guilty in past lives) should really take stock of things and listen honestly (close your eyes) forget the prestige, and marketing, and "real wood veneers" etc. etc. I most recently tried this with a fellow audiophile who was listening to a pair of his exotic mini monitors...I swapped out his speakers (KEF xQ1) with modified (and yes I can just hear you all laughing) Optimus Pro LX5 speakers. In blind testing using his choice of recordings and Stereophiles test CD, he was truly unable to accept that he was listening to Radio Shack speakers!!! Laugh as you will, the fact is with the veil removed he couldn't accept the sound which moments earlier (under blind conditions) he was marvelling at. Sad. |
Just to add something to Sean's post since he mentioned AR, there was that big fuss between the large Advent(a sealed system) and the JBL Century 100(which was ported)back in the 70's. The JBL had a lot of frequency deviations but would play much louder and seemed to have more drive(it was also a lot more efficient.) All of this was the "West coast sound" vs. the "East coast sound." Seems to me the manufacturers have changed but the war goes on. Some people love the inaccurate sound(which is ok) My point is, I thought "High end" was the pursuit of accuracy in reproduction. Not that it sounded good to select people. Of course, I can also see a manufacturers position but lets be honest about it, if we are going to accept some of these speakers then why can't Bose be accepted? They cost enough for crap they are! When you listen to a truly accurate speaker, it sounds -well-dull compared to others. However, it will sound better in a few months and with a wider variety of material once you get use to it. On another subject, I have found that in setting up my Vandersteen subs to mate with the 3A Signatures, that when set correctly, they do sound lean. The Vandy subs can be adjusted for a "Q" of just under .5 to something along about a "Q' of 1.5. As you go up in Q, the bass sounds more prominent. As you go the other way, it gets very, very tight and sounds lean. Now of course you can raise the level, but then output of the subs is exceeding the output of the mids and highs of the main speakers. Everything can actually be shown just as Sean explained above. The Vandersteen 3A Sigs seem to be set for a Q of about .7 or so. The subs integrate well set at about a Q of .6 to .7 You can set the Q lower but the bass becomes very lean and detaches from the music a touch. I really don't see how you get a sub to match without some control over the Q differences between the lower section of the mains and the sub. Roy makes a valid point above about phase relationships. I became convinced sometime ago that phase and time was an issue. I still stand convinced on this subject. One of these days, I'm going to give one of his speakers a run. |
Roy brings up some great and very valid points. Speaker design is obviously VERY complex and loaded with design trade-offs. Having said that, Roy's comments also point out that the room has to be taken into consideration i.e. how the drivers "blend together" and "load up" in the actual listening area. Since most designers / manufacturers don't take all of these factors into consideration, they end up with a product that lacks "universal" application and / or works well in some aspects but is quite limited in others. All of this for only a few thousand dollars : ) One of the points that Roy mentions is the phase shifts that take place within the audible band when using multiple drivers. Part of why people "love" single drivers is that this is less of a problem. Instead of dealing with multiple different radiation patterns, transient responses and phase shifts, you have one point source radiator. Most all of these problems are drastically reduced, resulting in a far more "unified" or "cohesive" presentation. You don't have to worry about how one driver blends with another because you've only got one driver. This is one of the reasons that i love my Ohm F's as much as i do, as limited as they are. Being a single driver design with the horizontal radiation characteristics that they offer, they do some things that no other driver / speaker can offer. At least, no others that i've heard. Drubin: Naming names gets hard to do, for both good and bad reasons. The "bad" reasons are obvious i.e. potential legal ramifications. Believe me, i've gotten more than a few emails about this subject. Only thing is, someone can't sue you for telling the truth using statements that are verifiable. As far as the "good" goes, i have a hard time finding any "manufactured" speakers that are worth recommending in stock form. It's hard to use something as an example when you can't find a suitable sample. If you want some basic recommendations, avoid ports and passives. Both introduce increased amounts of resonance and phase shifts into a system. I've posted links to a few discussions that cover this topic that i had over at AA, but i'll see if i can find them and post links to them again later tonight. Sean > PS.... Obviously, i'm NOT familiar with EVERY speaker or audio product out there. It is quite possible that there are some excellent examples out there, i just don't know of them or enough about them to use them as a reference. |
Avoiding ports and passives is a tall order. If I'm not mistaken, that would exclude most of the phase-and time coherent designers out there, including many models from Thiel (my 2.4's have a passive radiator and a Q of about .8), Vandersteen, Meadowlark, and even GMA (the Europa is ported). My request for naming names is not to ID who is good and who is bad but to illustrate what a high Q speaker sounds like vs, a low Q, etc. etc. I'm looking for organizing principles and examples of the members of the various camps, that's all. "In this corner, we have Brands X,Y,Z, who belong to the bass uber alles school and get there by doing.....And in this corner, we have the accuracy school....." |
Sean wrote: >>As far as naming specific speakers go, that would be hard to do, especially in stock form. >>Can you point me to a well designed speaker that offers coherent arrival of the sound, >>linear in frequency response without major abberations, offers minimal ringing at any given >>frequency while producing good bass extension? Quite honestly, i can't think of a single >>modern day product that meets that criteria. I can recommend one in STOCK form, which you might already know of. Green Mountain Audio C1.5i. Here are a portion of the specs from the user manual:- Type: Sealed box design with minimum baffle Phase Shift: +10 degrees @ 150Hz -10 degrees @ 8KHz +/- 1 degree 250Hz – 6KHz Xover Type: single-element, 1st order (6dB/oct) parallel Butterworth electrical & acoustical Xover Freq: 350Hz & 3KHz Polarity: Non-inverting I'm sure that there are others but these speakers I can recommend highly thru personal experience. NOTE: no affiliation of any way, shape or form with GMA. Merely a customer. Other than this, I agree with Sean's thread. With TWL's explanation. I arrived at the same conclusion myself. It's too blooming bad that the 1st question people ask after hearing a system is "where's the bass?". It's all in there, old chap, you ain't listenin'! After reading this thread I'm reminded of the LP I have by Milt Jackson "Ain't But a Few of Us Left"! |
Twl - I think there is another category of audiophile on this board. I haven't read all of the posts in this thread yet, however I'm an audiophile that can be placed in the weighty bass category. I love accuracy, transparency, wide and deep soundstage, halographic sound immersion and all of the cliched attributes found in first order designed box speakers and electrostatics. What leaves me flat with stats is the lack of dynamic bass response. If you're musical tastes range from Mahler to Black Sabbath and you've seen enough live concerts to understand what it is to feel the music you can't help but love impactful bass. Having said that, IMO there is a big difference between weighty, fast articulate bass and boomy wall shaking bass. In the final analysis bass is important to me, but not at the expense of articulation. I think you can have weighty bass that gives music a dynamic live presence without sacrificing the important highs and mids that give music an immersive quality. |
Dawgbyte, I tend to agree with you that dynamic bass with accurate timbre is a good thing, and a certain amount is required for decent sound reproduction. Of course, I am not discounting bass response in total. My intent was to make remarks that point out certain trends in audio systems and the music that they are purchased to reproduce, and how the system performance parameters(and buying decisions) are affected by the musical tastes of the user. If everyone only listened to acoustic chamber music, there would be little use for subwoofers or bottom octave reproduction. If everyone listened primarily to St. Saens Organ Symphony #3, then there would be a requirement for flat response down to the 16Hz bottom end needed for the 64' pipe on that piece. And, if the primary music played is designed to have pumped up bottom end, such as the pop music of today, it would only make sense that at least some mfrs. would produce audio products that follow this trend by the consumers. |
Hello Sean, I share many of your thoughts about the poor low-frequency definition of typical vented systems. But then one day I made the pilgrimage to Brighton, Michigan and heard the Classic Audio Reproductions T-1 in the home of their designer, John Wolff. I couldn't believe the tightness and naturalness of the bass from that big vented box. So, I went home and modelled the T-1 to get an idea of what it was doing. It turns out the predicted -3 dB point is about 75 hz; -6 dB is around 38 Hz; and -9 dB at about 20 Hz. That's an approximately 3 dB per octave rolloff! I've since designed several vented systems with rolloff rates typical of a good sealed system, with let's just say encouraging results. The box sizes are quite large, of course. Why would I do this when I can get the same results with a sealed box? I'm trying to minimize thermal compression, and woofers that have very low thermal compression are much better suited for vented box applications than for sealed boxes. I'd be interested in your comments on this approach. Thanks! Duke |
Drubin: Why do you think that i've said that it is difficult to reference "box stock" speakers? The pickings are phenomenally slim. Even those that do some things "right" are "hurting" in other areas. Bombaywalla: I don't doubt that Roy is capable of building a good speaker, i'm just not real familiar with anything that he makes. His input here has always come across as being both honest and intelligent. These are odd yet admirable traits for a product manufacturer on an audio forum. I guess that in itself speaks volumes about the way that he does things : ) Bigtee: I had subscribed to Hardesty's Audio Perfectionist for a time, but let my subcription run out. Quite honestly, I ran into problems downloading / printing it out. Richard was VERY good to work with though, making this less than trivial. I probably should renew my subscription as he at least has the "balls" to say what he thinks. I have to respect someone like that, even if i don't agree with them all the time. If someone isn't familiar with Hardesty's work, i would suggest taking a look at the "Watchdog" series of articles. Some of them are less relevent than others, but you'll at least get a feel for what he's capable of writing. Duke: When i first heard some CAR's, i thought that they sounded pretty good. They were somewhat "thrown" in a room with less than ideal placement and still managed to receive a standing ovation at an audio show. Given the less than stellar acoustics and lack of "hi-fi" installation, that says a LOT about a product to me. With that in mind, i thought that the bass was slightly tubby sounding and that there was s slight dip in extreme upper mids / lower treble region. As mentioned though, the bass problem may have had to do with less than optimum placement and show conditions, etc... Given that i wasn't familiar with ANY of the gear being used at the time, i don't want to throw stones at John's work. From what i could tell, it was quite good. Other than that, a shallow slope is great. Not only does this mean greater extension, it also equates to reduced phase shifts. My main concerns here would be the amplitude of the peak at resonance and the impedance at and near resonance. As you know, the bigger the peak that you have, the greater the oscillation. The greater the oscillation, the less control you have and the more ringing ringing. None of these are desirable traits. As far as impedance goes, the greater the peak, the less power transfer. The less power transfer, the less control. The less control, the poorer the sound. Both of these "problems" are common sore-spots with the mass majority of vented designs. For others that are just joining us or would like to re-visit some very "informative" threads that discuss low frequency characteristics of various designs, try these links over at AA. The first one here involves Dan Wiggins of Adire Audio along with Bobby Palkovic of Merlin. Needless to say, i made a LOT of "new friends" on this one : ) sealed vs vented Here's a post that i made almost five years ago about this same subject over at AA. It really doesn't cover any new ground, but simply shows that i've been relatively consistent in my stance for many years prior to the current uproar : ) deep and accurate bass means... There are several other threads that specifically deal with vents & Legacy's that also contain technical info. I didn't post links to those as there is one that demonstrates that Bose are superior products to Legacy's. I didn't want any of the Bose fans here to think that i was "on their side" though : ) Sean > |
Sean, The new APJ is now mailed and is no longer an online download. He just offered a new watchdog for subscribers only(#16.) For anyone desiring to see a pretty unbiased account of audio, read Hardesty's journals. The first two are a free downloads from his sight. It is interesting reading to say the least. You may not agree with everything he says(which he does mentioned as perfectly ok with him) but he really explains and sorts thing out. The one thing I really appreciate is the fact he gives you an explanation for everything he states as his beliefs. He also does not deal with the "What ifs" but the "What is." As a side note, I'm sure he will upset electrostatic / planer people! |
Sean, this is my favorite post from the "sealed vs vented" thread: "I should have known you had cranial-rectumitis when you asked the question "Are you capable of assembling a "loosely compiled gathering of parts" on your own?" For your information I'm a EE. As for your loosely compiled gathering of parts you can shove them where the sun don't shine." Sean your ego has no boundaries... you must have to grease every doorway in your house just to get that big head through. If you truly have a formula for success then get into the game and share it with the world instead of standing on the sidelines criticizing everyone elses designs and theories. Please do us all a favor, get yourself a business loan and enlighten our ears with Sean's Uber Box and price it for under 10 grand! |
