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

Soniclife

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Is there blind test research that backs this no measurement for dynamics claim up? My bias is that quite a bit of the difference is from our eyes, not all of it, but until you have controlled for sight I don't think you are going to get measurements and ears to agree.
 
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Music1969

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Is there blind test research that backs this no measurement for dynamics claim up?

It's a fair question. Would have to ask him to know for sure.

He seems like a very clever and thorough Engineer (long history as founder and Chief Engineer of Adam Audio, big in Pro Audio monitors for a long time) that probably has done this kind of blind testing... especially before getting on camera and claiming he has no idea how to measure dynamics and inviting other engineers that do know, to tell him how.

And he does say he's engaged with a University in Berlin to research this area.

I love his honesty in this interview. He's very clear on what he knows and honest about what he doesn't know, even with his pedigree in pro audio monitor design.

A very clever chap. I'd need to win lotto to afford the Hedd Tower Mains but would love to demo them at a dealer.
 
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MZKM

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I don’t see what the challenge is for measuring dynamics.

In terms of macro-dynamics, isn’t that just max SPL (within certain distortion parameters)?

In terms of micro-dynamics, wouldn’t the impulse, group delay, waterfall, spectrogram, etc. graphs tell you?
 

SIY

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I don’t see what the challenge is for measuring dynamics.

In terms of macro-dynamics, isn’t that just max SPL (within certain distortion parameters)?

In terms of micro-dynamics, wouldn’t the impulse, group delay, waterfall, spectrogram, etc. graphs tell you?

The problem is that "microdynamics" and "macrodynamics" are audio reviewer terms, not things with an actual definition.

It is not difficult to measure dynamic range, linearity, power compression, and similar characteristics, but that's not a good story to tell the folks who influence your buyer base.
 
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Music1969

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It is not difficult to measure dynamic range, linearity, power compression, and similar characteristics

But I guess what he’s saying is that a big box and small box can measure the same in all these things you list but still sound very different?

And he’s trying to show this difference in measurement? But hasn’t yet found a way in 30+ years of speaker R&D?
 

Purité Audio

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Just spent a fascinating afternoon with Mr Hedd U.K. a pair of ‘main towers’ are on their way here.
Keith
 

SIY

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But I guess what he’s saying is that a big box and small box can measure the same in all these things you list but still sound very different?

And he’s trying to show this difference in measurement? But hasn’t yet found a way in 30+ years of speaker R&D?

Yeah, I had trouble believing that as well. Both the first statement and the last. :cool:
 

RayDunzl

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Did he tell us how to measure speaker dynamics?
 

Frank Dernie

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It interests me to know what gives the impression. I have always assumed lack of dynamics was due to insufficient power handling leading peaks/loud bits to be under-reproduced.
After reading adulation in th press about the Spendor BC1 I sought out a dealer and went for a listen. On speech and string quartet they were really impressive but on orchestral and rock music very, very disappointing. I put it down to a heavy plastic cone and a voice coil capable of a maximum power handling of 15-watts and bought something else.
Accurate instrumental timbre, clean bass and dynamics have always been my main interest when seeking out a new speaker. I don’t expect realistic spatial information from stereo so have never been an imaging freak.
Lots of the speakers I have listened to fall down on at least one of my main deciding factors - often all 3.
 
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Music1969

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Yeah, I had trouble believing that as well. Both the first statement and the last. :cool:

He kinds of hints in the video that he's been in a lot of studios over the years, especially with his links with studios using his Adam Audio monitors.

And I guess that 'something' that he feels is missing from smaller boxes is dynamics - even if they can measure the same. He really emphasises that measurements tell you nothing about how the speaker will sound. He does have a lot of experience.

I ask respectfully but do you have professional speaker design experience?

Disclaimer: I've never owned any Adam or Hedd speakers. It was just a cool interview I found growsing Darko's YouTube channel.
 

DDF

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"Dynamics" are straightforward to measure as linearity and distortion over different power levels. There's no reason to inherently constrain the measurement to use sines, it can use any (dynamic) test signal you want if you put enough elbow grease into it (which I have). For example, you can use diff maker and run it over time synched files. There are other sneakey methods as well.

From my experience designing many speakers, I think he may be tripping up on a few things:
- certain subjective colourations can enhance perception of dynamics. For example, non flat frequency response can easily give perception of false dynamics especially if the upper mid range is lumpy
- room reverb fills in the temporal gaps between dynamics. I think "horn dynamics" are as much a function of their tighter radiation pattern as any high sensitivity
- thermal compression occurs. Fielder and many others published quite a bit in JAES over the years on what it looks like, and ways to help minimize it. The design info is out there

I attend many (many) live classical shows and live classical rarely "sounds" dynamic in the same way a stereo might. At times, you don't even know the sound is as loud as it is until your ear starts distorting. Good, clean, accurate stereo systems provide this same experience. First time I truly experienced it in my home was when I deployed NC400s with 1200W power supply.
 
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Music1969

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I think he may be tripping up on a few things:
- certain subjective colourations can enhance perception of dynamics. For example, non flat frequency response can easily give perception of false dynamics especially if the upper mid range is lumpy

He covers this in the video (he is referring to linear, flat FR)
 

SIY

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And I guess that 'something' that he feels is missing from smaller boxes is dynamics - even if they can measure the same.

I strongly disagree with that assertion. "Measures the same"? I can't find two different small speakers that "measure the same" much less a small vs. large speaker.

He really emphasises that measurements tell you nothing about how the speaker will sound. He does have a lot of experience.

That's very much the message his customer base appreciates. And a reason why I stick to measuring and reviewing these days.

Fortunately, we have lots of data to the contrary, starting at the top with people who don't have to bow to the demands of marketing to the fashion sector, like Heyser, Toole, Olive, Geddes, and Linkwitz. And doing measurements as part of my review process has been gratifying in how well they fit with what my subjective impressions are.
 

DDF

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He covers this in the video (he is referring to linear, flat FR)

He says even response this is mandatory but I didn't hear him say that non flat response enhances dynamics. Did I miss that? Can you point that out in his talk?
 
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Music1969

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He says even response this is mandatory

This is what I'm referring to. His entire premise about speakers sounding different in dynamics is on the assumption that all other measurements are very good, including linear response.

He could talk about non-linear response as you mention that can affect dynamics, but then he could talk about so many other variables. His premise is everything else measures very well.
 
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DDF

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That's very much the message his customer base appreciates. And a reason why I stick to measuring and reviewing these days.

More in response to Music1969: He doesn't actually say measurements don't tell you how a speaker sounds. That's ludicrous. What he was saying, indirectly, is that we yet don't know how to predict the tonal balance of a speaker just based on its spinerama. We can get close, but we don't know exactly how the ear integrates the late room response with the direct sound to create a complete picture of the tonal balance.

For example, take two speakers with near identical on axis (not hard with DSP) and different off axis, and for a given room, can eq be used in line to get tonal balance close? If yes, for which rooms? How does it vary by room (ie how late contribution reverb affect tonal balance). As far as I know, we don't know this yet with sufficient precision and I've read pretty much every AES paper on audibility of resonance, reflection etc. So, we need to do some voicing by ear. And then live with small remaining room dependencies. I 100% agree with this based on my experience and I'm very scientifically oriented FWIW.
 
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