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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.
sean
sean OP
6,231 posts
 
Drubin: How can i make this easier to understand? I'm not aware of any speakers in box stock form that i really like or think are phenomenally well implimented. On top of that, I don't know of any current production speakers that are sealed and of a low Q design. As far as sloppy bass response goes, head to your local audio salon and listen. If its got a vent of some type, you've got your answer.

Dawgbyte: Glad i at least gave you something to laugh about. Even if it was me you were laughing at.

If you read that entire thread, the guy that claimed to be an EE was asking for help in building / designing a subwoofer. As i mentioned in that thread, if he's an EE, why didn't he do the math himself? Didn't he trust his own skills and electrical engineering degree? As a side note, i had no idea who i was replying to or their level of skill or understanding, that's why i asked what i did. Besides that, just because someone has a degree ( IF they really did ) and sits at a desk engineering products, that doesn't necessarily mean that they want to get their hands dirty by building what they designed. That's the difference between a "desk jockey" and the laborers that actually make the products and keep the economy moving.

Other than that, i didn't see anybody post any information that refuted the points that i made. In fact, several of the arguments that were presented to refute my statements ended up supporting the points that i was making. While you may find the biggest point to be at the top of my head, facts is facts and marketing is marketing.

I didn't exactly see too many manufacturers willing to defend their "state of the art" products in that thread either. The ones that did didn't fare too well. One of the two that did participate partially acknowledged the points that i was making. At the same time, they also tried to convince me that one of their vented designs worked quite well for what it was. Given the limitations of the specific product being discussed, i agreed with his design approach. I also went so far as to state that their two-way design had better response than some large towers using multiple dedicated woofers.

The other manufacturer admitted that sealed designs are superior, yet could be expensive if seeking the ultimate in both extension and spl capacity. Their designs concentrate more on quantity than quality. The fact that they presented info about their own products that demonstrated the lack of engineering involved only helped to prove my point. On top of that, other parts of their rebuttal displayed further ignorance of the amplifier / speaker interphase and the relationship that impedance matching plays between them.

One questions for you. If i am / was "SO wrong" in what i was saying or how i was saying it, why didn't a knowledgable EE or speaker designer / manufacturer jump in there and slap me silly? If you don't think that HORDES of EE's, designers / engineers / manufacturers don't read that forum, guess again.

By the way, i don't use "grease". This stuff works much better as a lubricant and comes in all forms. You might want to see if they offer a product that is consumable by humans. It may ease your problems with constipation : ) Sean
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onhwy61's avatar
onhwy61
5,145 posts
 
Although well argued and quite informative the original post essentially is a argument of the type "the sound I prefer is right, and all others are wrong". If I've learned anything from reading on Audiogon is that educated and informed audiophiles have different values and tastes as to what constitutes good sound. Arguments based strictly upon measurements ultimately dissolve into disputes about the validity and methodology of the measurements themselves. While it's certainly possible to make a great sounding loudspeaker based solely upon measurements (Spica, Dunlavy and Quad ESL to name a few), it's telling that not all audiophiles agree that these speakers are accurate or even pleasing to the ear. In the end I believe right or wrong type arguments don't fully respect the wide variety of taste and values present in our hobby.
jrd351
332 posts
 
the creation and marketing of loudspeakers that cost more than a new or late model automobile do nothing to improve the hobby, the state of the art, or recorded music(accurate or not). they are built to be cash cows for the manufacturer and have no more value to most music lovers than a rolls royce does to a 'car' guy. the truth is the standards that where set years ago by allison,kloss,dahlquist,klipsh,fried and others have long been ignored to focus on marketing 'sizzle'to a fringe group of audiophiles who forgot why they liked music in the first place.
dawgbyte's avatar
dawgbyte
325 posts
 
Bombaywalla, yesterday I spent over an hour reading through this thread and the thread Sean linked to entitled "Sealed vs Ported" over on AA. Sean provides some valuable technical insights, but IMO his approach leaves me cold and unsympathetic to his cause. I think he takes pleasure in luring speaker designers onto these boards, so he can debate design theories and make unprovoked attacks on their motives and products. His attacks and insults on the Adire Audio designer are a perfect example. Sean is the classic "know-it-all" who would rather sit on the sidelines and criticize others instead of jumping into the game and going into business for himself. I'm sorry, but I'm not a fan of people who like to listen to the sound of their own voice.

I think it's time for Sean to answer some questions I have posed for him in the Dynamic vs Electrostatic thread here on Gon... which I actually meant to post here on this thread, so unfortunately it will appear out of context.
newbee
4,751 posts
 
Dawgbyte, You refer to Sean's 'cause' therefor I assume you have it pinned down. When I first noted his posts on this issue I thought he would in fact be marketing a speaker in the near future sporting a design which was in some way inovative in solving the tradeoffs between sealed and vented enclosures. Apparently this is not to be (good for him). What I have found objectionable, especially in a forum where the majority of readers are very impressionable, is his categorical denegration, by direct comment or implication, of a speaker design which offers valuable tradeoffs for many audiophiles. I'm sure he feels that he is passing on valuable information - I don't question his motivation, just his tactlessness and style in dealing with this issue. If I shouldn't use a vented speaker because most of them are POS, and he can't recommend a sealed enclosure type which would satisfy me in stock form, then what am I to do? What am I to do? I want to be a member of this club!!!! Help. :-)
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