Speaker sensitivity vs SQ
So what is the term for plain old lack of linearity of a driver? That it's output at 90 dB doesn't match it's output at 70 dB? Is this considered strictly as mechanical compression? Also, the best AMT's have amazing lack of such artifacts and incredibly robust power handling. :) One of the reason I'm a big fan. |
Phusis and Duke, I beg to agree and disagree. I have always said the more power the better. This is a relative statement, relative to efficiency and other factors such as the output capability of the speaker. A speaker can only do so loud. I have been listening to as many horn loaded loudspeakers as I can lately and in general they are very impressive or can be very impressive. It is certainly easier to get dynamic sound because they are so efficient and they go very loud. Now an ESLs volume capability is based on its Xmax which is very small in comparison to dynamic speakers. If you try to run it full range with bass laden material it will run out of Xmax pretty quickly and start clipping or rapping the stators. However if you do two things the situation turns upside down. These are, send everything under 100 Hz to a subwoofer array and design the speaker so that it is a full range line source. What you get is every bit as dynamic as a horn system and I think because there are no crossovers otherwise, an effortless naturalness that makes the speakers disappear. Line sources project power better than point sources. Because ESL almost match the impedance of air their transfer of power is very efficient even if their electrical efficiency is not. So, you have a very dynamic, low efficiency speaker system that goes very loud and has no crossovers above 100 Hz. Phusis, lets say you have two speakers that both clip at 120 dB at 1 meter. One has an efficiency of 103 dB/1watt/meter and the other 84dB/1watt/1 meter. With a paltry 2 watts the first is blasting at 106 dB and the second only at 87db. To get the second to 106 dB you need 160 watts and this is at 1 meter. At a reasonable listening distance you are easily under 100db, probably down towards 95 dB. We are not even talking about peaks here. The point is that low efficiency speakers require a lot more power to hit dynamic peaks, hundreds of watts. Duke, your friend has more work to do. There are so many factors involved that I doubt you can make a blanket statement that high efficiency speakers are all more dynamic than low efficiency speakers of various types given appropriate power. It is certainly easier to make high efficiency speakers sound dynamic and I would rather have a good sounding high efficiency loud speaker than an equally good sounding low efficiency speaker. The more power on a relative basis the better. Fortunately for me ESLs are more efficient than ever 89-90dB/1watt/meter and there are plenty of amps now that can drive them without farting or blowing up. I should be able to hit 100 dB without leaving Class A operation. |
We're nearly at the end of this one. Thanks for your post mapman and a couple of others on the same point. A large part of the answer to my question seems to be that efficient speakers cost more to build to the same SQ level in part because need to be a lot larger, in part because driver manufacturing tolerances are more critical. This accounts for the huge growth in low-efficiency small box speakers since the 80s. Indeed, since the 60s - does anyone else remember the introduction of the Goodmans Maxim? https://www.ebay.co.uk/itm/133504369128 Just out of school a friend of mine had a pair. Only 10.5 inches high. Great for a student room. Maxim has impressive sound quality for the size and surprising bass if you backed it against a wall. One might observe that avoiding high amplifier costs with efficient speakers is one side of a coin with high speaker costs on the other side. No free lunch after all. |
@phusis asked a bunch of good questions. My response: The round waveguide has a pattern width of 75 degrees and will sit atop the midwoofer box, somewhat reminiscent of some of Avantgarde’s models. So the configuration is "HMM" instead of "MHM". (We heard PBN’s "M2!5" speaker which uses the "HMM" configuration, and even at fairly close range with eyes closed it was coherent.) Passive crossovers, OTL and SET friendly impedance curves (nothing against active, but my target market is elsewhere). Multiple subwoofers south of 70 Hz or so. Obviously not cheap, but there will be some trickle-down to more affordable models. * * * Regarding dynamics: I'm friends with a recording engineer who, for decades, has been measuring the dynamic compression characteristics of loudspeakers, both home audio and prosound. He has amassed data on over a hundred loudspeakers. He measures the compression of peaks, something that might be called "short-term power compression", as it happens vastly faster than long-term thermal compression. Earl Geddes was the first to bring this up to me, and Floyd Toole exchanged a few messages with me on the subject. He sees it too, and said that it's an area which has not been adequately researched. Anyway my friend finds a strong correlation between efficiency and freedom from compression on peaks. I'm not going into the specifics because I consider them confidential, as he hopes to publish his findings some day, but in general high efficiency and large-diameter voice coils translate to freedom from compression on peaks. Duke |
@mijostyn -- Good post, but I'd have to disagree with below quote: A low sensitivity speaker can be very bit as dynamic as a high sensitivity speaker. It is just a matter of power. Sorry, but no. Anything approaching live dynamics calls for both high efficiency and power (with very high eff. all-horn designs less power is needed). It's not only a question of achieving fairly uninhibited SPL's and dynamic envelope, which in itself is no easy task, but doing so with headroom to spare - on the speaker as well as amp side. Indeed, headroom is your friend and aids ease of presentation. Of course, less than live dynamic levels would do for many, but even then (with low eff. speakers) headroom is likely sparse. Power is power, and where less efficiently turned into acoustic output is stored as heat and eventually power compression. |
@audiokinesis -- This is almost exactly what I’m working on, and had hoped to introduce in 2020 but... stuff happened that year... That is certainly interesting re: the similarity of approach, and thanks for your added/confirmative info here! Indeed, covering the whole frequency span from ~700Hz on up from a single driver/waveguide/horn element appears to be paramount. The current driver/horn constellation (and soon to be fitted with a bigger horn) of my main speakers sport a 2" exit with a 3" titanium diaphragm, and thus lends great energy and "breathing room" to its lower to central region. This does affect the upper octave however compared to smaller exits of 1 and 1.4" which don't roll off quite as early, though conversely at the expense of lower band energy and higher distortion here. Choices, choices; it's a matter of balance (and preference) with the implementation at hand, but I find it's worth the effort compared to adding another driver element, cross-over and point source. If I may inquire: what's the intended waveguide exit size of your upcoming design, and would the twin 15" bass/mids be configured D'Appolito style or with both of them below the OS waveguide? Btw, I'm thinking whether Timbers would've preferred a slightly lower cut-off than 800Hz with the M2's, but that the size of its waveguide simply won't allow it? Scaling up the size here likely would've made for a bulkier, and less commercial appearance. To the OP: sorry for veering off-topic. If nothing else what's elaborated above is an indication of a preference and a desired high eff. design path that seems less popular or visible not for reasons of lack of sonic prowess, but rather size requirements and design principle in particular. Few audiophiles appear interested in compression drivers and horns/waveguides, not to mention larger pro woofer/mids that extends into the central midrange; I'd wager it's largely conjecture aimed at a speaker segment that doesn't speak the conventional hi-fi narrative, and where auditioned their typically denser and more direct/present sounding nature mayn't appeal to those who're usually exposed to a leaner, more laid-back and softer/reverberative presentation. And may I just add: high efficiency doesn't automatically equate into easy or easier amp load. Less power is stored into heat for a given SPL, but a complex passive x-over here can still drain amps with less prodigious power supplies. For easier an more optimal amp load active configuration is required. |
At the time Bill Johnson was starting his Audio Research Corporation (1970), his reference loudspeaker was doubled pairs of the KLH 9 Full range ESL (two 9’s per side). High-sensitivity loudspeakers were very available at the time (I heard the ARC SP-2 and D-50 driving a pair of huge bass reflex speakers in ’71), though the new small---and rather insensitive---acoustic suspension designs (pioneered by Acoustic Research with their AR-1 and -3) were quickly becoming the norm. But the sound quality provided by the KLH 9 was preferred to all of them by Johnson (and J. Gordon Holt of Stereophile), this in spite of the fact that the KLH 9 was an extremely insensitive design, and presented an insane load for the power amp (highly capacitive, with a ridiculous impedance profile). Johnson then heard the new magnetic-planar made by fellow Minnesota resident Jim Winey, the Magneplanar Tympani T-I, and declared that it made the KLH 9 now unlistenable. While the T-I did not possess the high capacitance and impedance characteristics of the KLH, it was even more insensitive. Is there a more power-hungry loudspeaker than Maggies? Once again, Johnson’s reference speaker was an extremely insensitive design. He so liked the Tympani he offered to distribute Magneplanar through his dealer network. Yes, while Maggies present a load to power amps that more sensitive designs don’t, they also create a sound none of them do. The same is true of large full range ESL’s. Pick yer poison! |
There are so many varied considerations in speaker design that it is difficult to be versed in all of them. So, we are left to art and our own devises, hearing. We all have our theories and preferences which is what makes this fun.I concur tough with the rest of your post... Sorry if i seem rude....Anyway you dont read my posts anymore... 😊 My best to you.... |
Has anybody ever wondered by no two loudspeakers sound alike? Assuming there is only one accurate sound, that would mean that everyone except for maybe one company has it wrong.Sorry but this is completely non sensical... First "accuracy" is a complex chain of measured numbers, for example in the standard processing of designed pieces of electronic components, but "accuracy" in this sense had "no audible signification" except to certify that a piece of electronic component was rightfully designed.... Then the "accuracy of a sound" is in no way synonymus with the accuracy of an electronic design pieces or the accuracy of the audio system and the accuracy of sound is never reducible to them for his only source and cause...The "accuracy of sound" is a phenomenon mainly linked to the relation between the audio system and his embeddings linked to the ears/brain evalutation... Then "assuming there is only one accurate sound" is a sentence with absoletely no meaning....And accuracy of a sound in music, is not accuracy in the acoustical sense...Timbre for example is not reducible to tone accuracy only...The accuracy of a sound produced by an electronical design in a laboratory has nothing to do with the accuracy of a sound in a room... The sound did not come from our speakers to our ears directly in a pure delivery without any noise from any source, but on the contrary is the results of a complex acoustical interaction with the room....More than that the audio system is immersed in the mechanical dimension, in the electrical dimension and in the acoustical dimension, then the sound coming from our speakers is the signal/noise complex chain that is modified by these constraint i called the 3 embeddings.... Then your conclusion is also totally absurd because saying that all companies have it wrong is , like someone who want to recreate the wheel, especially, a non circular wheel....All company have it all relatively right in the limit of the trade-off implicated by electrical and mechanical constraints in the design of speakers and the choices they made...There is no perfect speakers, there is some better than others for some ears and for some goal.... Sound quality, timbre experience, imaging etc all these qualities come from the audio system in his totality embed in a specific room , in a specific house, and in a specific electrical grid.. Someone who think that human experience of musical sound come from the speaker design mainly is beside his shoes... Why there is no 2 speakers that sound like each other? The list of reasons is so numerous that reducing it to difference in electronical design and mechanical design of speakers is very misleading... But in audio thread the electronic design importance veiled for most eyes/ears the importance of the embeddings... A piece of electronic design cannot work optimally in a non controlled environment.... Is it not simple? |
OP, you are correct, the John DeVore video does not answer your original question. And for me it is a useful tool to dig deeper into your question. So, why don't manufacturers make efficient speakers? You might want to next ask, how do we determine if a speaker is efficient, what's the difference. And the video helps us understand that some manufacturers are not giving us an honest real world picture with their specs that we can rely on to make that determination. In other words, there are more hard to drive speakers for sale than an arbitrary cut off db number might tell us. I hope you will feel at some point that your question has been answered well enough. And then at some point you may decide you want a new speaker efficient enough to meet your needs. Caveat Emptor, we need to do our homework and not just rely on the published specs. |
A low sensitivity speaker can be very bit as dynamic as a high sensitivity speaker. It is just a matter of power. Has anybody ever wondered by no two loudspeakers sound alike? Assuming there is only one accurate sound, that would mean that everyone except for maybe one company has it wrong. More probably nobody has it right. There are so many varied considerations in speaker design that it is difficult to be versed in all of them. So, we are left to art and our own devises, hearing. We all have our theories and preferences which is what makes this fun. I personally don't care at all about efficiency. I separate sub bass from everything else because the considerations are so vastly different. I care about directivity, uniform radiation and radiation type (line vs point source). Because of the directivity mandate I prefer ESL line sources and horns (point source), one moderately inefficient 89-90dB/watt/meter and one very efficient 100+dB/watt/meter. Both are a much better impedance match to air thus the transfer of sound from the driver to air has inherently less distortion. Dynamic drivers sound rounded off to me as if the tips of the transients are missing (no idea if this is correct or not). Many like that "smoothness" and certainly prefer the size. For many it has been the only type they have been exposed to. ESL line source speakers are a bit tricky as they do not conform to the usual rules. Even though they are less efficient, because they project power into the room better than a point source an ESL playing at 90dB at 1 meter will be substantially louder and more dynamic back in the room. Than a dynamic speaker playing at 90dB at 1 meter. Because small ESLs can be rather timid I am of the opinion that if you are going to do ESLs get them 8 or 9 feet tall (depends on your ceiling). It is a major difference in performance, so much so that a pair of subwoofers will never be able to keep up with them, takes at least 4. As for subwoofers, we have been blessed with modern drivers, amps and crossovers. With enough power you can make a subwoofer do almost anything you want within it's volume constraints. The real problem is the room. If you have to you use multiple units and keep the crossover below 80 Hz. With some speakers like planar magnetics and ESLs there are advantages to crossing higher which means placing the subs in a symmetrical array otherwise you can put them anywhere as long as they are up against a wall. If you put a sub in a corner it is going to be louder than the others. Can you make an efficient subwoofer? Sure, I made one, or rather we made two. We put 30" Hartley woofers in 25 cubic foot enclosures and drove each one with 20 class A watts. Ridiculous would be an understatement but it worked. You can not use most modern subwoofer drivers in large enclosures. What happens is the voice coil bottoms out making a very disturbing sound. You could use multiple drivers so that each one sees a smaller volume but you still have a very big speaker. There is this thing now with dipole subwoofers. If you have been mislead to think these work just measure their performance. The data will make you cry. There is no circumstance under which a dipole subwoofer will perform reasonably flat from 18 to 100 Hz. I've never measured the efficiency of one but given the degree of cancelation going on I can't imagine that it will be very good. IMHO full range drivers by themselves do not cut it. You can get a very nice midrange and if you lock your head dead on with the driver some treble and in a transmission line enclosure even a little bass. You can do better with Parts Express, Madisound and a little smarts. Horns are great as they are directional and do not bounce sound all over the place. I love the visual statement some of the systems make. There is nothing cooler than those multicolored and wooden horns. Reminds me of "His Masters Voice" and boy do they go loud. If your thing is pee-watt amplifiers these are definitely your speakers. Good horns will not honk at you like PA speakers and like ESLs the micro-detail and transients are excellent as both are much more efficient at transferring sound to open air. Listen to a drum solo and those snare drum snaps. |
This isn’t an example of my preference but an efficient full range speaker. I guess it would also tick the manly man speaker box as well. I also mentioned the Phantom earlier again not as a preference but what can be done with small enclosures, active crossovers and DSP. I guess these are the opposite. https://www.jtrspeakers.com/jtr-noesis-215rt |
Speakers alone make no sound. Complete systems do. Need to examine the complete system before any meaningful comparison can be made. My understanding is MC prefers high efficiency speakers because they tend to be easier to drive and will work well with most any amp. There is truth to that. However high efficiency speakers also tend to be large and often expensive. Also bulky and more than many would prefer to have to deal with. That’s why the trend is towards smaller speakers that are necessarily lower efficiency if also extended in the bass. Amp choices for best possible performance are still plentiful but more limited. Many tube amps need not apply. MC is also a Tekton fan. Tekton does tend to offer larger speakers that are more efficient than most but not as efficient as true "high efficiency" speakers like Klipsch, Avantgarde, Volti, Classic Audio Design, and others. Notice most of those are also large and apply horn/waveguide technology to deliver true high efficiency in something some might want in their homes. Tekton offers good value compared to many for large more efficient than most speakers. So high efficiency alone can be a good thing but like always no one approach has all the advantages that all will care about most. Also I gather MCs mindset is real men like large manly speakers that may not be very pretty whereas you are perhaps a bit of a w-ss if you care about aesthetics and how they look in your house. That’s for the wife to care about and the real men to ignore. At least that is my understanding of how MC thinks, FWIW. |
millercarbon is recommending to exclude all Magnepan speakers as options. In doing so, he is recommending to exclude the best imaging, soundstage, midrange, and treble producing speakers on the market in their price ranges. It's fine that he makes such a recommendation, it doesn't mean anyone should listen to his recommendation or to me, for that matter. |
OP, It is about the cost of building/selling/ever decreasing market for large speakers as many have said. I wouldn’t want to pay for the speakers I luckily inherited, and the typically large house with large listening space they would sound best in. likewise, I wouldn’t want the challenge of finding small speakers that sound so good I have to have them, nor then have to pay for the additional power they would need. audiokinesis 8 CF! You made me drag out my drawings for the enclosures I designed, for the drivers I inherited, with the help of Electro-Voice Engineers and my AV Consultant for my current speakers. Deducting elements within the enclosure, I ended up with net internal volume 6.01 CF And, responding to my youthful excess, we designed a rear tuned port to squeak out a bit more from the 37 lb 15" woofers. I left the ports open in prior location, ’hear/feel those canons! I closed them when I moved here. Bass is tighter, bass imaging very good, I frequently advise front facing subs located near the mains to achieve imaging of bass. I advise against ports, if any front firing. They shouldn’t fit here. They are big, this house is a small split level. I got very lucky here, they fit, look, sound great. Whenever we go to other people’s houses, or look inside a house when they are for sale, I always look for where they would go. I see very few houses with a good space for them, even the big Victorian Monsters in the six historic districts of my town. They are in the background of my ’cleaning LP’s photo’ in my listing on eBay https://www.ebay.com/itm/133612076659 They are extremely efficient, I could shake the walls with 5 watts probably, I sometimes think about trying my friends 8 wpc amps, but they were driven by 30 wpc mono blocks originally, the amps still work, I have stayed in the 30-35, now 45 wpc size, not too big, not too heavy, not too much heat range. That is the max size tube amp I would want to pay for, or less. Thanks for inspiring me to look at those old drawings, jogs some great memories. |
Thank you nwres, bache, atmasphere for responding to my question. Which was: If there are such big advantages in high sensitivity speakers why do so many manufacturers build low sensitivity speakers? Thank you jetter for your kind words. To miller: I don't want you replying to my posts if you will not answer the question. It helps if you can read and your mind is not closed. John DeVore's informative and well presented video does not bear on my question at all. To everyone else: I am not interested in what speakers you like. Nor in how to build a high sensitivity speaker - I just want to know why most aren't doing it. There must be reasons and they are probably technical, or related to cost vs SQ. We are not there yet. |
lalitk, I've heard the Canterbury and other coaxial Tannoy speakers and liked what I heard. I just did not consider them in the discussion because they I did not consider them to be a single, full-range driver. But, they are certainly great sounding examples of fairly highly efficient speakers that are easy to drive and can be run with low-powered amps. I also agree they are quite nice to look at too. I have a friend who is now in the process of building a system using the coaxial Altec 604 drivers from Great Plains Audio. At one point, he considered an Onken cabinet, but, the available designs for this driver specify a 360 liter cabinet (one and half times the size of the Canterbury's Onken cabinet) and this was too large to be practical. Too bad, I like the sound of Onken bass reflex speakers. |
I have yet to hear the OB speakers Danny Richie offers in his various GR Research kits, but they are pretty darn sensitive (mid-to-high 90's) and are reportedly very transparent, natural at timbre reproduction, and dynamic as well. As soon as social interaction is again possible, I plan on inviting myself over to the Portland home of the Audiogoner who owns the NX-Otica (I think), which he pairs with the Rythmik/GRR OB/Dipole Sub, which I too built. |
Aside from your personal likes dislikes in speakers the main advantage of Highly efficient speakers (> 95 dB with 1 watt at 1 meter) is the greater dynamics that can be achieved. Doubling the power of your amplifier will only give you a 3Db gain in SPL. Lets take a look at the power requirements for a couple of speakers, Setting the max SPL at 116 Db. the B&W 603 S2 is rated at 88.5 DB @ 1 watt input. To produce 116 Db you will need a 1Kw amp. My old Altec A7-500's are rated at 103 Db at 1 watt and can Produce 116 dB with a little over 16 watts. To my ear this is why some speakers sound muted/sluggish on rim shots and other sounds that require fast response. disclaimer the math is approximant but close. My personal system uses a set of speakers that are rated at 84dB at 1 watt and my power amp is rated at 1Kw RMS and tests to 1.1 Kw/channel both channels operating.. I can only say that switching from a MC2100 to the larger amp was like cleaning a dirty windshild and bass is tight as a drum pun intended. |
@larryi, You may wanna add Tannoy Canterbury Prestige GR speaker to your list of speakers that has exemplified themselves in achieving excellent tonal balance from a single driver. The Canterbury’s sports a 15-inch dual concentric single chassis driver that incorporates two separate drive units, integrated into one. If you like, you can further read about the merits of dual concentric driver on Tannoy website. Here I wanted to express briefly, the frequency response from 15” driver is pretty flat throughout the entire audible frequency range. The Canterbury’s are excellent speakers capable of delivering very detailed, integrated, dynamic and warm sound. I also dig their traditional look with exquisite birch plywood cabinetry and champagne gold metalwork :-) |
Pa speakers are much more sensitive than hifi speakers, but produce more ditstortion and do not have the same frequency range. To compensate they require active filtering and subwoofers. Making a sensitive speaker isn't that complicated: a woofer with a stiffer suspension (= less lower frequency) and a compression horn tweeter (= more distortion). A pa speaker with the sensitivity of an average hifi speaker would require a truck full of amplifiers to achieve the same decibels. That's why in sound reinforcement only the max db level of a speaker is most important. for each 3 db more, the amplifier power has to be doubled! |
bdp24, I agree with you about the relative merits of Soundlab electrostatic speakers vs. the Altec Voice of the Theater speaker. The Altec tonal coloration is way too unnatural for my taste as well. At one time I considered buying Soundlab speakers. But, while most of the commercially available compression driver systems suffer from too much tonal issues for my taste, I've heard many custom systems that sound very good; I ended up with such a system. I feel the same way about many other high efficiency speaker types, such as full range single driver systems. I ultimately don't like their tonal balance and rough frequency response (notable exceptions are Charney Audio and certain Voxativ models). I like some systems that use "fullrange" drivers as wide range drivers in multi-way systems. In some, a woofer supplements the fullrange driver, in others, a tweeter is added on top. An example is the Soundkaos Model 42 (fullrange driver plus a Raal ribbon tweeer on top). My favorite system utilizes an old Jensen M10 fieldcoil driver (13" fullrange driver) in an open back cabinet (open baffle) operating full range, but with a first order high pass crossover to a tweeter supplementing the single driver (the system I heard had a Jensen RP 302 tweeter, but, I am told that a Western Electric fieldcoil 597 driver is better). |
Speaker sensitivity has little or nothing to do with sound quality. High or low sensitivity speakers are merely two different paths to same destination. Matched with the proper amplifier, either have the capability to produce satisfying sound quality. Of course, some will do this better than others but there are many variables much more important than a speaker's sensitivity. |
@phusis wrote: "What’s particularly interesting with high eff. larger speakers, to me, is that simplicity can be maintained when incorporating horns or waveguides fitted to compression drivers, and thus avoid some of the complexity issues that face low(er) eff. larger speaker designs. A 2-way high eff. design can be had with fairly large woofer/mids crossed to a horn/waveguide with very nice power response in the XO-region, though needing subs augmentation. I use such a configuration myself, now awaiting new horns from ~700Hz on up with a mouth area of some 2 x 3 feet for controlled directivity if needed, down to 500Hz for a smoother transition to the dual 15" drivers below." This is almost exactly what I’m working on, and had hoped to introduce in 2020 but... stuff happened that year... Anyway I designed a large-format Oblate Spheroid waveguide using Earl Geddes’ equations, like you targeting a 700 Hz crossover to twin 15" midwoofers. That 700 Hz figure is consistent with the findings of David Griesinger which Geddes subscribes to, and is very close to the 800 Hz crossover that Greg Timbers uses in the JBL M2. Imo the ability to cover the spectrum from there on up with a single driver is a major advantage over more "conventional" approaches, in addition to the other advantages of large drivers and high efficiency. And of course the way around the bass extension/box size/efficiency tradeoff relationship is to hand off the bottom couple of octaves or so to subwoofers. I’m rather surprised by how similar our approaches are. I knew we were barking up trees in the same forest, but didn’t realize it was the same tree! Duke |
@lalitk, Agree many worthwhile advantages to higher efficiency/sensitivity speakers. It does seem that to design and build this type of speaker requires a certain degree of effort, thought and implementation. Well worth it in my opinion. To be able to utilize a high quality but lower power amplifier (With simpler circuit/signal pathway) is a very good option to have. Charles |
there is plenty of money in a $50k plus speaker for fine drivers with best available energy in the gap Ralph, actually make that $15 k for Vandersteen Quattro, throw in built in subs w 11 bands of EQ and an easy to drive load One reason why Thiels don’t sound like Vandersteens, before the Mafia attack, I own both. BOTH. and Panels that store energy, electrostatics that sound like transformers....etc... its a brutal truth, move the accuracy ball forward or flavorize. Just know what your religion is...ha. enjoy the music.... |
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I don't know how to quote posts, but in reading this, I hope all have read what Tomic601 has posted above. It answers a lot of why some top designers have lower sensitivity speakers, but are still very easy to drive, even with lower powered tube amps. Vandersteen and Theil are time and phase correct and due to what Tomic said about pistonic drivers, speakers like Vandersteen's will be lower sensitivity. |
@djones51 -- With active speakers and DSP box size and bass extension are being challenged in interesting ways. Look at the Develiat Phantoms down in subwoofer range with appossing drivers and a lot of watts. The Phantom's to me are more an interesting development in what can be achieved from a very small sized speaker package than what's entirely successful in itself against speakers of larger volume; they may impress (some people) in the context of being very compact, but against larger sized main speakers and subs come off like they're working hard to sound bigger than they are. Going further into the high eff. realm with a comparison here only exacerbates this impression, which is to say: challenging physics in regards to size only gets you so far. Quite a few other interesting active designs (like the Genelec "One's") have immerged challenging their passive iterations (if they exist as such as well) to come out victorious and at a favorable price, and that's something to cherish. These however are usually compact designs for smaller to moderate spaces, and don't escape the limitations of physics imposed on them. Fortunately active configuration can had with large, eff. speakers as a solution of separate components, but this does require some tech understanding (that can be learned) with DSP's and setting up cross-overs, if they aren't pre-configured. @audiokinesis -- Now imo there are definitely some qualitative advantages to that higher efficiency, but in my experience the market for eight cubic foot speakers is rather limited. What's particularly interesting with high eff. larger speakers, to me, is that simplicity can be maintained when incorporating horns or waveguides fitted to compression drivers, and thus avoid some of the complexity issues that face low(er) eff. larger speaker designs. A 2-way high eff. design can be had with fairly large woofer/mids crossed to a horn/waveguide with very nice power response in the XO-region, though needing subs augmentation. I use such a configuration myself, now awaiting new horns from ~700Hz on up with a mouth area of some 2 x 3 feet for controlled directivity, if needed, down to 500Hz for a smoother transition to the dual 15" drivers below; coherency is paramount, and in conjunction with high eff. and sheer size is an intoxicating trait. Fortunately it's up to each individual to pursue the advantages afforded through high eff. and size, even if it isn't popular, and it mayn't be expensive. |
Of course, it all depends on one’s priorities in reproduced music. If dynamics is your No.1, high efficiency is for you. I myself am not willing to give up transparency and/or natural timbre reproduction to get dynamics. Are dynamics and transparency/lack-of-coloration mutually exclusive? I haven’t heard everything (including the Tektons), but from what I have, I find the two inextricably related.Interesting... My speakers Mission being less sensitive are better at timbre than dynamic... I will never exhange natural timbre perception for dynamic tough....For sure the 2 qualities cannot be separated on good speakers...My tannoy were good on the 2 front on equal measure...Alas! Too big for my room and needs i sold my 2 pairs .... |
The SoundLab ESL's are considered by some to be one of the best sounding line of loudspeakers available. They are also notoriously insensitive, and a very demanding load for a power amplifier They are also extremely transparent, and about as good at reproducing instrumental and vocal timbres as any speaker I have heard.. Then there is the Altec Voice-Of-The-Theater loudspeaker (A7), a very sensitive and easy-to-drive speaker. I lived with a pair for six months, and consider it to be as colored a loudspeaker as I have ever heard. Intolerably, comically colored. It's akin to a video monitor with it's color temperature WAY off, and its contrast control turned to max. Nasty, ugly sound, like chewing foil. If you compare the two, and prefer the A7 because it is more sensitive/easier to drive than is a SoundLab, we'll have to agree to disagree. That's like preferring a smaller house to a larger one because it's cheaper to heat and cool. Of course, it all depends on one's priorities in reproduced music. If dynamics is your No.1, high efficiency is for you. I myself am not willing to give up transparency and/or natural timbre reproduction to get dynamics. Are dynamics and transparency/lack-of-coloration mutually exclusive? I haven't heard everything (including the Tektons), but from what I have, I find the two inextricably related. |
I have owned all manner of speakers--conventional sealed box, bass reflex box speakers, electrostatics, planar magnetics, etc., and all types of speakers, with varying efficiencies, can deliver decent sound. But, over time I have gravitated toward high efficiency speakers because they can be utilized with my favorite amplifiers (most of which are low-powered tube amps) and because they tend to deliver superior dynamics. I know there are theoretical reasons for this--low power being delivered to the driver for any given volume level means less heating of the voice coil (heating causes an increase in resistance that then reduces the ability to deliver more power, in other words the driver output does not increase linearly with increase power (i.e., dynamic compression)--but, whether or not this is true, I tend to find higher efficiency speakers more dynamic sounding). I currently own a system with twin 12" woofers in an Onken cabinet, midrange supplied by a compression driver/horn combination, and highs delivered by a bullet tweeter. Horn systems like this tend to be large in size, which is why the industry went away from these systems, particularly when stereo required installing two speakers (and HT requiring even more speakers). I don't think it was sound quality that killed horn-based system. |
@ clearthinker An excellent first post. As you can see by Duke’s response above you are correct, there are other factors that are impacted by and to be considered when evaluating a speaker’s efficiency. MC’s response to your thread is somewhat puzzling, you do seem to "get it". Encouraging to see at least some get it. Not surprised at all to see the O P does not. |
There is an inevitable tradeoff relationship between box size, bass extension, and efficiency. And it’s a fairly brutal relationship. If you keep the same bass response, every 3 dB increase in efficiency calls for a DOUBLING of box size. So compared with a 1/2 cubic foot 85 dB mini-monitor that goes down to 40 Hz, a 97 dB efficient speaker with the same bass response would be SIXTEEN times the size (four doublings of box volume), or EIGHT cubic feet. Now imo there are definitely some qualitative advantages to that higher efficiency, but in my experience the market for eight cubic foot speakers is rather limited. Anyway my guess is that the higher costs and the box size penalties attached to high efficiency are the primary reason why low efficiency speakers dominate the marketplace. Duke |
I agree that speaker manufacturers don't, but should, publish their impedance graphs. However, I also believe that there are a plethora of amplifiers that can power most, except for the ridiculously low impedance speakers, and they sell for reasonable prices nowadays, particularly if purchasing used. Thiel speakers and other hard to drive speakers are still as popular as ever. Thiel owners seem to find amps that make them sing and they love their speakers. |
I'd go with mahgister. AR 18s speakers (88dB) driven by a Rotel RA-414 amplifier (35W) can rock the place with 50-60 people whole night long and like that every weekend for years. How much easier to drive you need them to be? I am sure there are armchair theories, but in real-use practice that is all one may need. Skipping humongous speakers (Moabs anyone?) leaves more space to cram another few people in the room. |
+1 newres, well said. Speaker manufacturers ask for 10s of thousands of dollars, play fast and loose with sensitivity numbers, and (usually) don’t publish any impedance graphs. Mostly we’re left to hoping that JA has tested the speaker and published results Hate car analogies, but here goes. How much? $80k Horse power? Don’t know Torque? Hmmm, good question weight? Not sure... |
b_limo1, great video, have seen it once before. Interesting perspective. tomic601, When you say "don't confuse low sensitivity with poorly engineered load". I feel they are closely related. And I believe this is John DeVore's point in the video. I know of a high end speaker that is rated at 90db at nominal 8 Ohms (2.83v at 1 meter), have listened to it many times at a friends place. But when you look at the measurements of that speaker it has dips in the impedance down below 3 Ohms as low as 2.6. The speaker maker is only telling us a partial truth with their specs. It is only a 90db speaker for some of the frequencies and in effect a much harder to drive speaker to pull out all the audible sound well. Which I believe plays into the issue pointed out on the video of 1W per meter vs 2.83v per meter can be deceiving. With this particular speaker, you need an amp that doubles down on power when you halve the impedance to sound right. In other words it needs an amp designed for low efficiency speakers. |
