Dr. Klaus Heinz of HEDD Audio (ex ADAM Audio) - measuring speakers, in particular speaker dynamics

[Krunok]

Interesting amir. So listening to @mitchco's experiment recordings tells little, compared with the experience of listening in person?

@mitchco described his listening experience in detail. He provided those recodings so we can listen to them and compare our impressions with description of his impressions. Not to mention that he went to an effort to properly integrate subs with LS50 to match frequqency and phase response with his "big speaker" setup and provided measurements to prove that. In other words, his experiment is a proper comparison, unlike "next door" subjective impression method.

 

[Music1969]

@mitchco described his listening experience in detail. He provided those recodings so we can listen to them and compare our impressions with description of his impressions. Not to mention that he went to an effort to properly integrate subs with LS50 to match frequqency and phase response with his "big speaker" setup and provided measurements to prove that.

I was only asking @amirm specifically his thoughts, in reply to his post...

I already posted my reply to @mitchco earlier in this thread.... link: #31 ;-)

 

[Krunok]

I was only asking @amirm specifically his thoughts, in reply to his post...

I already posted my reply to @mitchco earlier in this thread.... link: #31 ;-)

Here is the point: Hedd Tower Mains consist of 2 elements: TMS36 subwoofer and TM80 "small speaker". Sure it looks really big, but that is because there is a TMS36 + TM80 + TMS36 put vertically on top of one another. If you arrange them differently, especially if you use only one TMS36 that sits aside of TM80, it wouldn't really look that big.

Here are their specs:

As you can see TM80 reaches down to 80Hz so it definitely needs a sub to act as a full range speaker. It is quite similar to the KEF LS50 that @mitchco used for it's experiment - LS50 specs here:

What I would like to know is what would happen if you take TM80 and repeat @mitcho experiment with LS50 + Mitcho's sub vs TM80+TMS36 combo. But I doubt you can do such comparison by listening them "next door".

What I do believe is, once you get the frequency and phase response right for both combinations the only thing that would be different is their "sonic" characteristics that can be well described with their Spinorama measurement charts.

IMO "big" speakers are of 2 types: they are either enlarged small speakers with additional woofer (like my Harlechs) or they are small speakers that share the same box with array of woofer drivers. So, if you take a small speaker, add a good sub to it and do the integration job well (as @mitchco did) I see no reason why it wouldn't sound "big" beacuse that is exactly what designers of big speaers are doing.

 

[amirm]

Interesting amir. So listening to @mitchco's experiment recordings tells little, compared with the experience of listening in person?

I did not listen to his files so can't comment on this work. We had the LS50 and Salon 2 for a few weeks and I listened to them quite a bit. The two are not the same animals. I have heard the LS50 countless times at shows too.

 

[Music1969]

I did not listen to his files so can't comment on this work.

I more-so meant the idea (methodology?) of listening to binaural recordings and playing back over headphones and trying to come to a conclusion.

i.e. if they sound the same (in terms of 'bigness') over headphones, what can be concluded? And equally important, what can't be concluded...

To me the more interesting thing about @mitchco's experiment is not the recordings but the fact that he had expectation bias that the big JBL's would sound bigger but in the end both systems (with EQ and subs) sounded more similar than he expected. I do trust his ears and his experience.

As I mentioned to him earlier in the thread, I wish I was there on the day, to listen to this fascinating experiment.

 

[FrantzM]

Some of you may find this interesting. I can't post a link, but if you search for this, you should find it quickly:

Archives: John Dunlavy (rec.audio.high-end forum posts 1997-2001)

Have not researched these yet. I know the power of bias... HAving heard differences between speaker cables and Interconnect cables myself ....

Dunleavy speakers are usually large but there is something belling about their sound... A "bigness" from a lack of better word that is nto a distortion, it disappear if the reproduction/recording doesn't call for it .. but when the score requires that sense of weight, of mass or scale .. Oh Boy! DO they!!! Better than most speakers I have heard. The last time I have heard a Dunleavy speaker about a decade ago, I did find the upper mid and the treble not to be the last in refinement when compared for example (then 10 years ago) to what a Dynaudio Esotar would do. On that note Dynaudio Evidence series were also in my mind something special when it came to that sense of "bigness" and generally great sound ( discontinued, perhaps ,I should look for a pair ...) ... Most small speakers plus subs do continue to my mind and my ears (not blind) to sound bigger than without subs but not realistically ...
Sorry about the OT .. Let's get back to the OP.

 

[napilopez]

I do think sighted bias plays some role in the perception of "size," which is why I found @mitchco's piece fascinating when I read it a while back.

My subjective experience so far tends to be the opposite of some of the people here. To me, bookshelves/small speakers, so long as they have decent extension, tend to seem "bigger." This isn't a comment on acoustics, so much as the fact that for me the music experience is heavily tied awith the illusion of sound coming out of thin air in front of me. The bigger the speaker, the more I'm reminded it's coming from a particular source.

It's for this reason also that I also prefer my HT system without a center; center speakers just completely kill the illusion for me, even when identical to the L/Rs. Given I'm always seated at the central position when I'm listening "seriously" (and no one else in the home cares about these matters things as long as they can hear dialogue clearly), I don't need the center for proper spatial cues either.

 

[mitchco]

I did not listen to his files so can't comment on this work. We had the LS50 and Salon 2 for a few weeks and I listened to them quite a bit. The two are not the same animals. I have heard the LS50 countless times at shows too.

Sorry man, I have huge respect for you and this site providing real world measurements, thank you. But you are missing the point...

 

[amirm]

Sorry man, I have huge respect for you and this site providing real world measurements, thank you. But you are missing the point...

Considering that I didn't pay attention to the point, it is hardly surprising that I missed it.

 

[amirm]

I more-so meant the idea (methodology?) of listening to binaural recordings and playing back over headphones and trying to come to a conclusion.

Binaural recording is a common research tool for acoustics. Harman for example used it to get listener input from people from around the world for automotive sound, showing that race made no difference in preference (their competitor had said that they knew what sound asian people wanted because they were asian).

I have also read it used in a lot of university research where they capture the sound in a room and then bring a lot of students to listen using headphones.

So the technique is valid.

 

[amirm]

I should add that just like any technique, there are limitations of course. Bass sensation for one doesn't exist in headphones so that can't be replicated. You are also at the mercy of what was recorded, which may not be what was heard by listeners. A test should be performed in situ to show that the recording was similar to what was experienced live.

 

[Music1969]

Binaural recording is a common research tool for acoustics.

Noted but I was asking about using binaural recording specifically for this particular discussion... not just the use of binaural recordings in general.... again:

i.e. if they sound the same (in terms of 'bigness') over headphones, what can be concluded? And equally important, what can't be concluded...

Bass sensation for one doesn't exist in headphones so that can't be replicated.

Noted. A good point.

 

[Krunok]

Noted but I was asking about using binaural recording specifically for this particular discussion...

He answered your question specifically: "Harman for example used it to get listener input from people from around the world for automotive sound ."

It would certainly be nice if @mitchco was able to wire both sets of speakers so they can be easilly be switched but such switches are hard to find. But anyway, I believe that binaural recording, especially when recorded by professional studio recording engineer, are showing the truth about these speakers.

 

[mitchco]

There is no mystery here folks. Using powerful audio DSP, one can eq and integrate whatever subs and mains one has to a preferred target response and they are going to sound more or less the same. You can hear it on the binaural recordings I made for two very different directivity loudspeakers. I was also able to compare the LS 50's (plus subs) with the Kii THREE's and D&D 8c's. If the frequency response measures the same, the "audible" difference is in the speakers directivity index which determines how much of one's room is mixed in with the direct sound reaching one's ears at the listening position. That's it. No mystery.

However, people have preferences and some folks prefer a more diffuse sound (i.e. more room sound mixed in with the direct sound - they are here effect) versus a more focused holographic sound (i.e. more direct sound and less room sound - i.e. higher directivity - I am there effect). Sometimes it comes down to music genres where folks that listen to acoustic and classical seem to enjoy a more diffuse sound whereas for pop, rock, or most mono multi mic'd or ProTool'd recordings, folks prefer a higher directivity speaker to hear more into the recording and less room. I prefer the latter.

So whether a Kef LS 50 plus Rythmik subs versus the JBL 4722 Cinemas or the JBL M2 or the Revel Salon 2 with or without subs, using state of the art DSP software that works on the speakers magnitude and time domain responses, independently all set to the same target frequency response, and listening at reference level (83 dB SPL) are going to sound (no surprise) virtually the same. The only real audible difference is how much room is mixed in based on each speakers off axis response (e.g. spin-o-ramas) and of course depending on how dampened or lively ones room is. I prefer more lively even though I spent 10 years in recording studio control rooms which were more on the dampened side. Granted, beyond reference level, the JBL 4722 with dual 15" stereo cabs and dual 18" subs will smoke the LS50's, but at 83 dB SPL reference level, none of these speakers are breaking a sweat.

The binaural recordings are of good enough resolution to record the difference between two extreme directivity speakers for most people being able to clearly hear and identify the difference (thanks @Music1969 ). Most other speakers will fall in between the two extremes I used in the article. So if you took the time to listen to the binaural recordings, thank you, and if you heard the difference, know that most other speakers difference would be in-between these two extreme examples of low and high directivity loudspeakers that you listened to. The proof is in the recordings.
PS. As noted int the article, you can't feel the subs in the binaural recordings

 

[maty]

When using DSP for the entire frequency range, the sound is much equal, true. But for good? Maybe it is the same ... from below, acting as a bottleneck that prevents you from appreciating details in the best recordings.

Obviously, it will depend on the DSP quality.

I am more in favor of some loudspeakers with very flat frequency response. If needed, the low frequencies are equalized and not the entire range. I also prefer that they have a large dispersion, but that will depend on the personal taste, the room, the placement of the speakers and whether the listening is in the near or far field.


PS: I am talking about music, very good recordings, high DR and with acoustic instruments. With music already very processed in the studio the use of DSP will be much more benign, I say. And cinema too.

 

[Music1969]

He answered your question specifically: "Harman for example used it to get listener input from people from around the world for automotive sound ."

How does that comment apply to this discussion of 'bigness' of speakers (and dynamics of big vs small speakers) that this thread is about though?

I wasn't asking about the general use of binaural recordings... not in automotive.

Again i.e. if they sound the same (in terms of 'bigness') over headphones, what can be concluded? And equally important, what can't be concluded...

His comment about bass on headphones is more specific to this discussion though.

 

[Krunok]

How does that comment apply to this discussion of 'bigness' of speakers that this thread is about though?

Your question was this: "Noted but I was asking about using binaural recording specifically for this particular discussion... ".
My comment applies to Amir's answer for binaural recording being legit method to evaluate loudspeaker quality.

 

[Music1969]

Your question was this: "Noted but I was asking about using binaural recording specifically for this particular discussion... ".
My comment applies to Amir's answer for binaural recording being legit method to evaluate loudspeaker quality.

Correct, "for this particular discussion..." means this discussion on dynamics of big vs small speakers... the comment about automotive isn't really specifically related to the discussion of this thread.

Again i.e. if they sound the same (in terms of 'bigness') over headphones, what can be concluded? And equally important, what can't be concluded...

His comment about bass on headphones is more specific to this discussion though.

 

[Krunok]

Correct, "for this particular discussion..." means this discussion on dynamics of big vs small speakers... the comment about automotive isn't really specifically related to the discussion of this thread.

Using binaural recording to evaulate SQ of loudspeakers in cars vs in rooms is pretty much the same thing - the idea is to capture FR and directivity characteristic. And that is what is all about in the big vs small speaker comparison - IMO there is no such thing as "dynamics" that can explain it.

 

[Music1969]

IMO there is no such thing as "dynamics" that can explain it.

Noted. This is the meat of the discussion. Would be great if Dr Heinz can join. This entire thread is based on his comments in the Darko video interview. Would be great for him to expand here.