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What's Left In Speaker Design To Reduce Distortion/Increase Detail Retrieval?

Axo1989

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Detail retrieval isn't a term in ITU BS-2399. It is something used by recent audiophiles. It didn't exist even a decade ago I think and I have no idea what it means or its precise definition.

Pffft, semantics. :p

Anyways, as a non-designer, here is what I found out by reading several technical articles.
  • Distortion is already below audible levels when listening to program material. It is still high in sub-bass & bass frequencies, but we tolerate it very well.
  • The dynamic driver design is almost 100 years old and has survived when compared to other alternatives due to its durability.

I'd wager we hear distortion at various levels under varying circumstances: dynamics and music type come to mind. Subjectively my recent larger system sounds better/clearer at higher levels than my previous system could manage. I've heard bigger systems that do better still. Can't back that with a controlled trial of a statistically significant cross-section of the population of course. But I think research into certain relevant specifics is a bit thin.

We have extracted as much as possible from DD, only incremental changes are happening and it is something not always audible though it could be quantified.

The thread appears to be about incremental changes. It doesn't dismiss the obvious role of other improvements toward SQ (including room acoustic treatment and DSP).

All the research and investment seems to be on headphones and surround sound technology, not loudspeakers. With BT headphones all the rage and music being consumed through streaming, loudspeakers might become a niche that only grandpas listen to. :p

Research goes where the market and the money is, naturally.

And I'm not a grandparent: even when I am I doubt I'll care for argumentum ad populum any more than I do now. :)
 
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MattHooper

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Detail retrieval isn't a term in ITU BS-2399. It is something used by recent audiophiles. It didn't exist even a decade ago I think and I have no idea what it means or its precise definition.

Really? You can't figure out what someone could possibly mean by speaking of one speaker retrieving more detail from a recording than another? I find that
baffling.


Anyways, as a non-designer, here is what I found out by reading several technical articles.
  • Distortion is already below audible levels when listening to program material. It is still high in sub-bass & bass frequencies, but we tolerate it very well.
  • The dynamic driver design is almost 100 years old and has survived when compared to other alternatives due to its durability.

Good points. Especially alluding to the masking qualities of actual program material.

We have extracted as much as possible from DD, only incremental changes are happening and it is something not always audible though it could be quantified.

All the research and investment seems to be on headphones and surround sound technology, not loudspeakers. With BT headphones all the rage and music being consumed through streaming, loudspeakers might become a niche that only grandpas listen to. :p

I'll stick happily to the grandpa posse. No headphones for me. I suspect speakers will live on for a long time.

I think we often have a tendency to feel like our latest system is the best sounding one we've ever had. But how much might it be more sideways movement rather than straight up in quality? I think one can make some pretty obvious changes for more impressive sound, for instance if you've moved from some older stand mounted speakers to newer big floor standing speakers, where you get dynamics/impact and scale you never had before. I myself, though I've also owned stand mounts, have mostly gone through a succession of floor standing speakers that tend to go down to between 35 - 25 Hz. I'd love to be able to snap my fingers and have every speaker I owned pop in to the room to compare, just to see how much the sound of my system has "really" improved with newer speakers over time (or not).

Either way, I certainly find my system seems to keep up very well. I sure wouldn't swap it for anything I've heard today, or recently.
 

Philbo King

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As expected, a range of replies, thanks.

So take for example something that measures great like the Revel Salon 2. What if anything might be done to improve it's performance? First, stick to material/mechanical
"improvements." For instance is it possible that some cost-no-object level of additional damping/bracing of the cabinet could yeild any audible benefits? (Anecdotal reports seem to suggest Acora is on to something with their nothing-special drivers placed in fully granite cabinets in that respect...maybe...).

Could the drivers plausibly be advanced to yield even lower distortion, with audible benefits?

Anything else mechanical?

Would making them active designs, in of itself, audibly improve on those speakers? Digital crossovers yield audible improvements?

I'm sure one could get right in to DSP which will can possibly improve the performance of many speakers in-room. Though I don't think I'm talking about that, so much as
the engineering associated just with the speakers themselves.
Some work has been done with speaker cone position and velocity feedback to the amp circuit, forming a servo system to more exactly control the cone to reduce distortion. I think there exists opportunity to use optical feedback (reducing sensor mass) but I'm not very familiar with existing speaker servo technology; it is all likely to be proprietary.

Here is one site that talks about it:
Caveat Emptor - I don't know anything about this particular company...
 
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Thomas_A

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One easy way to reduce distortion is to use ACE bass in the amp. It is a kind of feedback but not a mechanical one.
 

Purité Audio

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I had a listening experience today that put me in mind of this thread. "How much do you get with some of the newer approaches to speaker design?"

My Brother-In-Law (BIL) is in town. He's sort of an old-school Stereo Review/ASR oriented audiophile, not in to "woo-woo" stuff at all, more oriented towards studio level design, and interested more in advancements like active speakers. Though where he lives, he doesn't get to hear much of what he can read about. Today I brought him to a very accommodating local high end store (where I bought my Joseph speakers) who carries the Kii Audio 3 speakers which my BIL wanted to hear. It was a great time.
(BTW, he previously listened to my system and I brought him to my reviewer pal's place where he heard $65K Estelons).

I was able to listen to some Spendor classic (though new) 1/2s, which I'd really wanted to hear. I also heard some large floor standing speakers from Triangle (french). But we spent by far most of the time listening to a wide selection of music on the Kii 3 speakers (without the bass module). (A lot of prog rock too, since he loves that genre).

To compare first what I heard from the Spendors: The Spendors struck me with that wonderful rich but clear tone that I enjoy from the classic Spendor sound (though in this case a bit more neutral and forward than some older modes). The general sound of voices and timbre of instruments were very natural - there was a combination of density and body that gave voices a sense of in-room solidity, yet without edge, sounding appropriately human and soft. A very tricky balance IMO. Highs were open and airy, giving a sense of "happening live, not canned sounding." Eyes closed there was a good sense of hearing *something like* the gestalt of live voices and instruments. To my brain the timbre of the sound was generally "correct" to the impression I carry around in my head of live acoustic sources, but there was still some sense of homogenization to everything, a slightly softened presentation, a slight lack of purity and clarity. I found listening very compelling, but ultimately would be happier with some other speakers that
sound 'right' to my ear, but sound less homogenized.

The Kii Audio 3: I've heard them numerous times now and today just re-enforced previous impressions. They sound generally clean, mostly "invisible" as sound sources, yet unlike some speakers that "disappear" they don't sound wispy, the Kii Audio 3s have meat on the bones, with a very even balance from bottom to top. Where some speakers you might get more of the top end skin hits of a bongo (on some of my reference tracks) the Kii Audio 3s gave that detail too, but also the weight of the hits on the bongos as well. Midrange was satisfyingly complete, no sense of suck outs emphasizing one thing or another, so everything sounded balanced, and yet variations in recordings/vocals sounded obvious too. A monitor sound without being punishing. And of course they did that wonderful trick with such deep, controlled bass from a relatively small speaker.
I could hear more control, more tonal individuation between bass instruments, vs the same tracks on the two other speakers I listened to in the store.

And my Brother In Law? He was very impressed. He's not big on describing sound, but essentially he thought the Kii 3s were terrific and really just the type of gear and sound he would be looking for, if he's to purchase another speaker (he currently owns Sonus Faber speakers he bought ages ago). Of all the systems he has heard so far on his trip hear, I had the impression the Kii 3s would hit his bulls-eye the best.

Ok what did I find the Kii 3s, the more "advanced" active-based speakers brought to the table?

Well....I heard nothing at all paradigm changing. I've heard plenty of other audiophile passive speakers that impressed me a lot more, and that rendered a number of those tracks with more "you are there" scale, clarity, timbral realism etc (to my ears). For instance my old Thiel 3.7s dug out plenty of nuance and timbral precision, dynamics, clarity, imaging etc as well. I wasn't hearing anything "wow" at all or especially "advanced" from the Kii 3s. More subjectively, while the Kii clearly had some advantages in frequency range, clarity and precision, nothing sounded quite as natural (eyes closed test) to me as some of the stuff I heard on the old Spendor design. And frankly, after listening to the Kii speakers for a while I wanted to run home and hug my system. I find the sound soooo much more beautiful and beguiling at home. Not a fair apples to apples comparison, but the general character of the Kiis didn't want to make me keep listening.

So, on an ultra subjective level...purely based on "what I prefer" while I could hear the Kii speakers do some excellent things, they left me cold. On a subjective-trying-to-be-more-objective level, just in terms of "judging the overall sound quality" they sound "different" than many good passives but much "better?" Eh.

It sort of reminds me of the Single Ended amplifier blind test thread on this site, where a tube design with some of the most wretched measurements and poor SINAD is put up against a properly measuring design. The difference turned out to be subtle, some people even struggling to hear a difference. In the same vein, while clearly speaker design IS making advancements, in the end perhaps the latest designs won't always necessarily result in large sonic differences vs competing (or older) designs. A bit of us audiophiles making mountains out of sonic molehills...which is what we do, as enthusiasts.

I don't think that means of course nobody can find some new speaker design obviously much more to their liking, and be very enthusiastic about some of the problems they are solving. Even in the Big Picture, relatively small differences can seem really big to us when we care about them.

And of course the above is just a personal encounter with a few speakers. Nothing about it entails the question I posed is moot. It's interesting to ponder what aspects can still be improved, sonically, (even if taste is left to the listener) in modern speaker design.

That's my take today, FWIW.
Matt you really have to compare speakers in the same room, remembering something from a dem in 1984 really just does not cut it, bottom line modern contemporary actives just let you hear more, they are just more transparent than traditional ‘drivers in a box’ , doesn’t mean ofcourse you will like them especially as you ( and most of us in fact) have grownup listening to traditional designs.
For a really valid comparison, borrow those Kiis, measure your room with REW, implement any requisite filters in the Kii ‘control’ adjust the tonality of the Kiis to your taste with the boundary gain /tone control functionality then directly compare.
Keith
 
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Marc v E

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This question popped in to my mind simply from some recent experience listening to some speakers at another audiophile's place.

I currently listen to some smaller floor standing speakers with good quality drivers (Joseph Audio Perspective 2 Graphene) and I find there to be a gob-smacking sense of clarity
and detail in to recordings. Along the lines of "how could it get better than this?" (And I've heard lots of other speakers).

Then I go over to my Pal's place and listen to a pair of big ol' Estelon speakers, one of the newer "it" brands in high end audio circles. I forget which new model, but they retail for something like $65K. Now, most of us have had plenty of experiences showing us that money doesn't necessarily buy you any better sound in high end audio. But I have to say, even though the presentation ultimately wasn't to my liking as much as my own system, they just seemed to obviously dig out more sonic information in the recordings. So for instance drums on a track on my system would be well placed in spatial terms, and I can hear if the drums were placed in a reverb. But the Estelon speakers just seem to effortlessly carve out precisely where the drums are in the soundstage and the precise acoustics or added reverb around the drums...and exactly where that reverb "ends" is more vivid and obvious. Basically there is this constant sense of more sonic information, presenting more precision about what is in the recording.

Which had me wondering what accounted for these differences. Better drivers? The more heroic efforts that went in to removing the influence of the Estelon cabinets? The whole design?

Now, that's just accounting for why this question was on my mind. Anyone can simply ignore the above example (it's just my subjective impressions after all) but still get to the issue I'm wondering about:

What is left in terms of speaker design to achieve, in terms of lowering audible distortion and hence retrieving more neutral sonic information from recordings?

(I add "neutral" because of course one can always hype a speaker's high frequency response to increase perceived detail...that's not what I'm talking about).

Are we done? Or is there more to achieve in terms of materials and design (drivers, cabinets etc)? Is a very flat frequency response all there is (since resonances will purportedly show up in frequency response)? Or could we take a speaker that measures very even, yet some upgrade in driver material/design or even more reduction in cabinet resonances may yield even higher sonic performance, retrieving some subtle details that were obscured before?

Where can we go from here?
I'm sure there's room beyond speakers like the Genelec 8351/8361 and the speakers you heard in terms of sinad. However in term of real world improvements, ie those that we can hear, I'm more inclined to say it's in the quality of recordings and multiple speakers for exact placement of instruments instead of a stereo image by 2, than speakers with a higher sinad.

The reason I'm saying this is that I heard the 8351 and left with the feeling not much could be improved upon but for the varying recording quality. I thought the speakers were absolutely amazing btw.
 

tuga

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So take for example something that measures great like the Revel Salon 2. What if anything might be done to improve it's performance?
The Salon2 produces a massive directivity change above 8.5k and the CSD shows a lot of rubbish when compared to a Kef Reference 5.
 

FrankW

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The Salon2 produces a massive directivity change above 8.5k and the CSD shows a lot of rubbish when compared to a Kef Reference 5.
708Revfig06.jpg
1017KEF5fig05.jpg

708Revfig10.jpg
1017KEF5fig10.jpg

Tell us about the audio consequences of "massive directivity change above 8.5k" and "the CSD" when you compared both blind/approximate level matched at same position in room relative to you.
 

tuga

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708Revfig06.jpg
1017KEF5fig05.jpg

708Revfig10.jpg
1017KEF5fig10.jpg

Tell us about the audio consequences of "massive directivity change above 8.5k" and "the CSD" when you compared both blind/approximate level matched at same position in room relative to you.

I am sure the two speakers sound the same when listened blind and all this talk about the importance of directivity is a hoax...

nzDUs7o.png

kXlcmRi.png
 

tuga

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Meanwhile you audiophiles can't ever figure this out
BlindVsSightedMeanLoudspeakerRatings.png

Is it a quadratic equation? o_O

Edit: OK, I Googled and it seems to have come from the Gnostic Gospels.
 

Schollaudio

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What passives are under 1%THD.
Here are two of my DIY designs both measured in the same room with the same levels and mic distance. The measurements are scaled the same too. This is as close to a fair comparisons as I can get REW, MiniDSP mic in a normal room.

1st is a JBL 2206 with JBL 2431 passive at 1500hz.

2nd is an AE TD15S and Faital 140 active at 600hz.

Note how low the JBL distortion is until about 70hz. Also, it's smooth and has some good 2nd order dominating parts of the FR.

Note how low the AE TD15S distortion is until 300hz where there is a box issue and 400 where there is a cone issue. But still pretty good overall.

Put the JBL on top the AE and now we have under .5% at nice full sound levels. Or what I'm using now is the 18sound 6nd430 and Wavecore tw030wa11 crossed to the AE at 250hz. I'm using active for the AE to 18 but passive is easily done.

Dayton sells several reasonable woofers and tweeters that can be integrated to get under 1% to about 70hz. If you peruse Voice Coil Test Bench, Hifi Compass, ASR you'll see getting below 1% below 70 hz is a bit harder but also possible and might be best with an active design keeping the crossover in the 100- 300hz range.

Back to the OT, IMO, what's left is still proper integration of the parts currently available to designers and DIY today. Go back to 80s KEF, good on axis, off axis and phase response. Also, integration into the room.
 

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FrankW

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I am sure the two speakers sound the same when listened blind and all this talk about the importance of directivity is a hoax...
So no clue about audible correlation to measurements, just bluster. Ok.
 

tuga

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So no clue about audible correlation to measurements, just bluster. Ok.
Can you get me the following 3 pairs of Ultima2s: a regular one with the BBC dip and the change in directivity and the dirty CSD, an identical to the regular one but with a clean CSD, and an identical to the regular one but with a smooth off-axis directivity?
Happy to endure the deaf blind testing.
 
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