Marantz AV 10 installed: - Early Review and Impressions.

[TLS Guy]

Here is a comparison of two different perfect speakers. One has a 12dB/oct LR crossover. the second one has a 24dB/oct LR crossover. They have perfect frequency response. They have perfect crossovers at the same frequency. Assume the same drivers. The perfect phases are entirely different. The only place that the speakers are close to being in phase is at 20Hz. At higher frequencies than the crossover frequency, the drivers are almost out of phase. Have your ever reversed the phase with one channel and noticed what happens to the sound? How do you intend to correct this with room EQ over the bandwidth of the speakers if they are different? All real speakers are worse.

These two perfect speakers have the same voicing but you will never be able to correct them.

View attachment 73922

The respective system phase curves are the grey and dotted blue curves. The green and dotted purple curves are the driver response with the crossovers. The text in the pic is meaningless for this example.

I am not daft, the phase of the three front speakers are precisely matched. The surrounds are minimal phase designs, and anyway with the huge change in location, phase is not an issue. I do not use room correction as it is not required. There is no significant out of phase condition, and Audyssey is happy in the speaker distance and levelling.

 

[PaulBe]

I am not daft, the phase of the three front speakers are precisely matched. The surrounds are minimal phase designs, and anyway with the huge change in location, phase is not an issue. I do not use room correction as it is not required. There is no significant out of phase condition, and Audyssey is happy in the speaker distance and levelling.

What problem are you having with my example? If you are using high level crossovers with RCL parts, all speakers are minimum phase. If you are using low level crossovers, please describe them. Phase is an issue with any spaced pair that is used to create image. When there is no correlation, none of this matters.

The angle between Left and Right is a huge change in apparent location. Change the phase of one of the speakers and hear what happens.

Phase has to be the same in any channel pair to make a good image. The holographic image is fragile. In a multi-channel system, that means any possible channel pair, or combinations up to and including all the speakers. This includes between your precisely matched Fronts and your minimum phase surrounds. What is the system phase of every channel pair in your layout with respect to MLP? I'm not really expecting an answer.

Making assertions like "anyway with the huge change in location, phase is not an issue." is a dog that 'don't hunt'. It's just your assertion. You are not describing a different 'zone' in another room. Perhaps you have never heard a fully integrated surround system, or noticed how some recordings make use of multiple channels to create image.

Recordings are variable. Some have highly correlated sound between all channels and need a phase match to sound their best, or to even hear some details as they are intended to be heard - from two channel to multi-channel recordings. Some recordings have simple uncorrelated ambient surround sound and don't require any special handling.

Are you using Audyssey just to set just distance and level? Works for me. Maybe I'll try it.

 

[TLS Guy]

What problem are you having with my example? If you are using high level crossovers with RCL parts, all speakers are minimum phase. If you are using low level crossovers, please describe them. Phase is an issue with any spaced pair that is used to create image. When there is no correlation, none of this matters.

The angle between Left and Right is a huge change in apparent location. Change the phase of one of the speakers and hear what happens.

Phase has to be the same in any channel pair to make a good image. The holographic image is fragile. In a multi-channel system, that means any possible channel pair, or combinations up to and including all the speakers. This includes between your precisely matched Fronts and your minimum phase surrounds. What is the system phase of every channel pair in your layout with respect to MLP? I'm not really expecting an answer.

Making assertions like "anyway with the huge change in location, phase is not an issue." is a dog that 'don't hunt'. It's just your assertion. You are not describing a different 'zone' in another room. Perhaps you have never heard a fully integrated surround system, or noticed how some recordings make use of multiple channels to create image.

Recordings are variable. Some have highly correlated sound between all channels and need a phase match to sound their best, or to even hear some details as there are intended to be heard - from two channel to multi-channel recordings. Some recordings have simple uncorrelated ambient surround sound and don't require any special handling.

Are you using Audyssey just to set just distance and level? Works for me. Maybe I'll try it.

Your post is wrong and idiotic on many levels.

While it makes some sense to minimize phase aberrations of the front three, the benefit will only be at the MLP, and as soon as you move left or right the time path will be different. As for the other speakers, because of the varying time paths this phasing of speakers is not an issue. This is not the same thing as careful phasing of the drivers on a single speaker. However, almost all speakers are awash in phase shifts. Even if you use fourth order filters, then at crossover phase is shifted by a whole cycle, and a square wave looks like a sign wave. The only speaker that could reproduce a sound wave in mid air, is Peter Walker's Quad ESL 63.

So what you are spouting is absolute irrelevant nonsense.

Yes, I use Audyssey to set distance and levels, but it never gets the sub levels quite right. This version is closer, but a db or two off. This newer version of Audyssey does a much better job of "room Eq" and is not significantly different from my curve at the MLP. But I don't need an extra layer of frequency manipulation. Actually most of this comes down to baffle step compensation, which is in fact speaker position dependent, but my speakers have variable BSC which can be optimized to position.

 

[PaulBe]

Your post is wrong and idiotic on many levels. Mmmm...No. I know you don't like to lose, but, trying to knock an imaginary chip off my shoulder while retaining the chip on your shoulder is not a good conversational technique beyond adolescence.

While it makes some sense to minimize phase aberrations of the front three, the benefit will only be at the MLP Sort of. Example - some 2 channel recordings purposely throw an image to a location far different than between a channel pair. Phase is used to manipulate the sound, and matched phase between speakers is essential to preserve delicate image information. Your assertion works when all the correlated information is in the front channels. As soon as you add correlated information to the surrounds, it makes sense to minimize phase aberrations to all the channels, and the benefit will still be mainly at MLP. Pink Floyd and Tomita make great use of these techniques. This ability to throw sound can be done acoustically as well as electronically. Think some classical music , and as soon as you move left or right the time path will be different Of course. There is no free lunch . There can be Only One perfect seat in the house regardless of the number of channels. Don't move! There are Only about 5-9 perfect seats in a large theater and most people don't care, but, if you buy movie tickets online you see that these prime seats are gobbled up because some people do care and can hear the difference. As for the other speakers, because of the varying time paths this phasing of speakers is not an issue Time paths are corrected in the processor. The AV10 corrects to .01 meter = .394". Time correction for unequal distance is Not the same as having the same physical distance between speakers and MLP - it's a trig problem. If time correction isn't an issue, why correct time? This is not the same thing as careful phasing of the drivers on a single speaker Of course. This is a separate issue, and related because we are arguing about the word 'phase'. We do agree that careful phasing is important in a single speaker. We do agree that minimizing phase aberrations of the front three is important - which means all three front speakers need to be the same for maximum performance. However, almost all speakers are awash in phase shifts Yes! Then, make them awash in the Same phase shifts so correlated information will have the least image distortion. Even if you use fourth order filters, then at crossover phase is shifted by a whole cycle, and a square wave looks like a sign wave. The only speaker that could reproduce a sound (sic. I'm sure you meant square wave) wave in mid air, is Peter Walker's Quad ESL 63 Xactly! It's the only one I've ever seen. We established this a few pages back.

So what you are spouting is absolute irrelevant nonsense. Mmmm... No.

Yes, I use Audyssey to set distance and levels, but it never gets the sub levels quite right. This version is closer, but a db or two off I use AEQ - Auto EQ - in my DSP crossover to do a basic balance of the frequency response in my two dedicated Subs that are at the Front wall between L&C and C&R. Then I do a manual tweak to fine tune. The distance between the two Subs is 1/2 wavelength at 120HZ so I achieve a sidewall cancelation at 120hz. This produces a cardioid response from the front dedicated Subs - think waveforming. The waveforming cardioid response depends on frequency and phase shaping. Doing a good job here minimizes sub bass sound leak to the rest of the home. This newer version of Audyssey does a much better job of "room Eq" and is not significantly different from my curve at the MLP. But I don't need an extra layer of frequency manipulation I am very sceptical of any room correction from midrange on up. I'm also sceptical of some corrections below the midrange. IMO, room correction is best used from about 4X the Schroeder Frequency and below. Actually most of this comes down to baffle step compensation, which is in fact speaker position dependent, but my speakers have variable BSC which can be optimized to position All systems that use DSP speaker control have variable BSC. It's called a 'shelving filter'. You can accomplish much the same thing by using the bottom GEQ's in the AV10.

Most of my response is typed in Red, and embedded in your post. Here is a pic of careful phasing between drivers in a single speaker. It's one of my speakers. The crossover frequency is 600Hz at 36dB/oct - electroacoustic. The crossovers are IIR DSP. All 7 floor channels are the same. The tweeters are matched pairs - except for the Center tweeter. Careful phasing of drivers in a speaker matters. Careful phasing of correlated signals between any group of speakers matters.

 

[TLS Guy]

Most of my response is typed in Red, and embedded in your post. Here is a pic of careful phasing between drivers in a single speaker. It's one of my speakers. The crossover frequency is 600Hz at 36dB/oct - electroacoustic. The crossovers are IIR DSP. All 7 floor channels are the same. The tweeters are matched pairs - except for the Center tweeter. Careful phasing of drivers in a speaker matters. Careful phasing of correlated signals between any group of speakers matters.

View attachment 73931

I'm not disputing getting individual speakers to have a good phase response. However for analog filters only first order crossover can have linear phase, and the problem with that is that there is huge driver overlap, which creates huge problems to solve. Only active crossovers with DSP can really solve this problem.

However, it is absolutely not essential at all to have all speakers identical, that is the part that is nonsense. In any event there is a pecking order, as flat FR and an an off axis response that closely matches the axis response is higher in the pecking order than a perfect phase response.

 

[AcuDefTechGuy]

On the previous units ambience was only marginally improved. However, with the AV 10 you really hear the acoustic of the hall, and the resounding echo from roof rear and sides, with correct and realistic timing.

Anyway, let’s forget about all the other stuffs. Is your AV10 still giving you all the excitement and thrill after the honeymoon period?

 

[TLS Guy]

Anyway, let’s forget about all the other stuffs. Is your AV10 still giving you all the excitement and thrill after the honeymoon period?

Absolutely. The unit is incredibly good and I have not had to do further adjustments. I have one of my brothers visiting from England. After he listened to a concert, he said, "you would not know you were listening to loudspeakers." On this speaker system it really is close, very close to the concert hall experience. I never, ever thought it would be possible to get this close to life like concert experience.

 

[AcuDefTechGuy]

Absolutely. The unit is incredibly good and I have not had to do further adjustments. I have one of my brothers visiting from England. After he listened to a concert, he said, "you would not know you were listening to loudspeakers." On this speaker system it really is close, very close to the concert hall experience. I never, ever thought it would be possible to get this close to life like concert experience.

Very nice.

And this concert hall ambience experience is with just using Dolby ATMOS and not using any DSP like “Concert Hall” or “Stadium” DSP?

 

[PaulBe]

Very nice.

And this concert hall ambience experience is with just using Dolby ATMOS and not using any DSP like “Concert Hall” or “Stadium” DSP?

I'm not aware that any DSP features like "Concert Hall" or "Stadium" DSP are part of the AV10. The AV10 appears to be just very good at reproducing low level detail. It's better than my old Emotiva RMC-1L.

 

[AcuDefTechGuy]

I'm not aware that any DSP features like "Concert Hall" or "Stadium" DSP are part of the AV10. The AV10 appears to be just very good at reproducing low level detail. It's better than my old Emotiva RMC-1L.

Even better.

Unlike Yamaha's million DSP modes.

 

[PaulBe]

I'm not disputing getting individual speakers to have a good phase response. However for analog filters only first order crossover can have linear phase, and the problem with that is that there is huge driver overlap, which creates huge problems to solve. Only active crossovers with DSP can really solve this problem.

However, it is absolutely not essential at all to have all speakers identical, that is the part that is nonsense. In any event there is a pecking order, as flat FR and an an off axis response that closely matches the axis response is higher in the pecking order than a perfect phase response.

Here is a good video. A detailed discussion of phase matching starts at about 46:50 in the video:

Important comment at the video:
"This guy is talking about what I've been saying all along. That phase coherence and the phantom imaging that comes along with it is one of the most important elements of immersive audio. When I first set up Atmos, I accidentally achieved that. I say accidentally because at the time (2017 to 2018) I really didnt have any idea what I was doing with Atmos and Immersive Audio. Heck I was in the learning phase with basic surround sound. And when I set up my Atmos speakers (because I had just upgraded to an Atmos capable receiver, so I said what the heck, I'll just check it out) and the resulting soundfield was so effective it was mind-blowing. It took my system from sounding "pretty decent" to rivalling and in some ways, exceeding the experiences I got from the local cinema. I was frankly flabbergasted. It didnt make any sense to me why suddenly my system shot off into the stratosphere. It was years later that I figured out it had to do with the phase coherence of all the speakers in the system. I would like more experts to discuss how to achieve that coherence between all speakers, ESPECIALLY between the ear-layer and the height-layer."

 

[TLS Guy]

Here is a good video. A detailed discussion of phase matching starts at about 46:50 in the video:

Important comment at the video:
"This guy is talking about what I've been saying all along. That phase coherence and the phantom imaging that comes along with it is one of the most important elements of immersive audio. When I first set up Atmos, I accidentally achieved that. I say accidentally because at the time (2017 to 2018) I really didnt have any idea what I was doing with Atmos and Immersive Audio. Heck I was in the learning phase with basic surround sound. And when I set up my Atmos speakers (because I had just upgraded to an Atmos capable receiver, so I said what the heck, I'll just check it out) and the resulting soundfield was so effective it was mind-blowing. It took my system from sounding "pretty decent" to rivalling and in some ways, exceeding the experiences I got from the local cinema. I was frankly flabbergasted. It didnt make any sense to me why suddenly my system shot off into the stratosphere. It was years later that I figured out it had to do with the phase coherence of all the speakers in the system. I would like more experts to discuss how to achieve that coherence between all speakers, ESPECIALLY between the ear-layer and the height-layer."

Mostly bunk and nonsense.

The speakers do need to sound similar. They do need to be as phase coherent within the limitation of accurate frequency response and good match of axis and off axis FR. Phase coherence within a speaker could only be achieved with a single driver or very good coaxial. There will never be phase coherence in speakers that are in different positions. That is impossible and will be different for every listening position.

Now we get to the real lunacy, the bulk of the sound is going to come from the front three speakers, and they need to be large enough to handle the spl.

You will not put any of these speakers in the ceiling, or one of the left or right speakers in the center.

But you can put adequate speakers in the locations required.

The auto set up programs like audyssey are adequate to tell you if there are phase aberrations great enough to have an impact, and I have personally tested that.

So yes, all speakers need to be good speakers and not have significant aberrations. Some crossovers will alter phase enough to be a problem, but I am confident that Audyssey will tell you that.
And yes, I get excellent phantom imaging in the room and huge depth of sound field beyond the front speakers.

 

[PaulBe]

Mostly bunk and nonsense.

The speakers do need to sound similar. They do need to be as phase coherent within the limitation of accurate frequency response and good match of axis and off axis FR. Phase coherence within a speaker could only be achieved with a single driver or very good coaxial. There will never be phase coherence in speakers that are in different positions. That is impossible and will be different for every listening position.

Now we get to the real lunacy, the bulk of the sound is going to come from the front three speakers, and they need to be large enough to handle the spl.

You will not put any of these speakers in the ceiling, or one of the left or right speakers in the center.

But you can put adequate speakers in the locations required.

The auto set up programs like audyssey are adequate to tell you if there are phase aberrations great enough to have an impact, and I have personally tested that.

So yes, all speakers need to be good speakers and not have significant aberrations. Some crossovers will alter phase enough to be a problem, but I am confident that Audyssey will tell you that.
And yes, I get excellent phantom imaging in the room and huge depth of sound field beyond the front speakers.

Your reply is what I expected. I posted what I did so other people who are really interested in what industry professionals know will have ready access to it, and, the stuff you just wrote for perspective.

Now be sure to tell that guy, Lon Neumann, who mixed sound for Michael Jackson, and many other world class artists, that he is full of 'mostly bunk and nonsense'. Add your comments to the YouTube video. It will be a hoot!

You have a nice looking room. I have a similar arrangement with the soffit.

Here is a front pic of my setup:

As you can see, LCR are exactly the same. All 7 floor speakers, including Surrounds and Backs, are the same drivers, same crossovers, tweeter pairs are matched, and yes the phase match matters. Lon Neumann and I are in agreement about phase matching. I listen to the results every day! I hope that someday you get to listen to a setup with phase matching. May it open your mind and ears.

 

[everettT]

Your reply is what I expected. I posted what I did so other people who are really interested in what industry professionals know will have ready access to it, and, the stuff you just wrote for perspective.

Now be sure to tell that guy, Lon Neumann, who mixed sound for Michael Jackson, and many other world class artists, that he is full of 'mostly bunk and nonsense'. Add your comments to the YouTube video. It will be a hoot!

You have a nice looking room. I have a similar arrangement with the soffit.

Here is a front pic of my setup:
View attachment 74046

Surrounds and backs are the same - same drivers, same crossovers, tweeter pairs are matched, and yes the phase match matters. Lon Neumann and I are in agreement about phase matching. I listen to the results every day! I hope that someday you get to listen to a setup with phase matching. May it open your mind and ears.

I'd say Dr. Mark knows what he is talking about 99% of the time, some just don't like his bluntness. Hopefully this can be understood the longer you're around.

 

[PaulBe]

I'd say Dr. Mark knows what he is talking about 99% of the time, some just don't like his bluntness. Hopefully this can be understood the longer you're around.

I'd say Dr Mark knows some things well, and very little about other things. This phase match issue is his blind spot. He does have a couple of years on me. I have only 55 years in the hobby, and only 35 years in pro audio.

 

[TLS Guy]

I'd say Dr Mark knows some things well, and very little about other things. This phase match issue is his blind spot. He does have a couple of years on me. I have only 55 years in the hobby, and only 35 years in pro audio.

Do you have the exact spot marked on your floor and the height at which all those speakers are in phase? You would also have to clamp your head in the same spot. Sound has both direction and time which is part of the phase relationship. You are spouting absolute bunk, as well as that so called "expert" in that you tube video.
Your speakers will not have perfect phase even for one speaker. The phase relationships will change even for one speaker as the speakers are separated in space, and the time relationship and therefore phase relationship between the drivers of a single speaker will alter depending on your location in the room, and how you are seated. The issue becomes compounded the more speakers you add. The issue will still be present, though somewhat ameliorated, if you use zero phase shift digital crossovers in active speakers. You can not make a passive speaker with zero phase shift that has multiple drivers and an analog crossover. Even then it would only hold for one speaker at one solitary position from the speaker unless it had a full range driver with zero phase shift. However, even single drivers have some finite phase shift.

Now, I'm not saying you should not take steps to minimize phase shifts in speaker design However, flat frequency response takes precedence over phase shifts. There has only ever been one truly phase coherent speaker and that is the Quad ESL 63 electrostatic speaker.

 

[PaulBe]

Do you have the exact spot marked on your floor and the height at which all those speakers are in phase? You would also have to clamp your head in the same spot. Sound has both direction and time which is part of the phase relationship. You are spouting absolute bunk, as well as that so called "expert" in that you tube video.
Your speakers will not have perfect phase even for one speaker. The phase relationships will change even for one speaker as the speakers are separated in space, and the time relationship and therefore phase relationship between the drivers of a single speaker will alter depending on your location in the room, and how you are seated. The issue becomes compounded the more speakers you add. The issue will still be present, though somewhat ameliorated, if you use zero phase shift digital crossovers in active speakers. You can not make a passive speaker with zero phase shift that has multiple drivers and an analog crossover. Even then it would only hold for one speaker at one solitary position from the speaker unless it had a full range driver with zero phase shift. However, even single drivers have some finite phase shift.

Now, I'm not saying you should not take steps to minimize phase shifts in speaker design However, flat frequency response takes precedence over phase shifts. There has only ever been one truly phase coherent speaker and that is the Quad ESL 63 electrostatic speaker.

The AV10 is a very nice processor. Enjoy your thread.

 

[PENG]

I'd say Dr. Mark knows what he is talking about 99% of the time, some just don't like his bluntness. Hopefully this can be understood the longer you're around.

Agreed to a point, at least in this case/topic, but it would have been to a much larger extent if he had gone into engineering, preferably electrical (or electrical and electronics, or measurements/instrumentation etc.) in those days, instead of medicine lol..

He, or we, can't convince guys like PaulBe, who clearly is on the subjective side, he emphasized the importance/relevance of subjective measurements, that I fully agreed, but on trying to establish what he experienced as reported in the last few threads on phase, I would put much more importance on any of such subjective measurements done in blind AB, at least single blind if not double blind. That of course is nearly impossible to do for home entertainment environment, even Harman would have difficulty doing it to Dr. Toole's satisfaction (I don't know that but can imagine it).

There is some threads on this very topic, below is one, and I would think the OP, if interested, might want to read it to see the tons of different opinions, many based on their own research/reading, and experience.

As to "experts" @TLS Guy , I don't know who he would consider expert, but if Dr. Toole is one he might consider as an expert, then he would probably be please to see that Dr. Toole and him might agree on this topic:

Linear Phase in Studio Monitors - the responses of Dr. Floyd Toole, Dr. Wolfgang Klippel, Andrew Jones, and James Croft | Audio Science Review (ASR) Forum

Here are a couple examples, noted/quoted by ASR members in the linked thread above:

Dr. Toole (again, just quoted by an ASR member, not sure if 100% accurate)

Naturally I did some tests, reversing polarities of loudspeakers, and introducing phase shift to distort musical waveforms — listening for big differences. They weren’t there. At least not in the music I was listening to, through the loudspeakers I was using, from the musical sources I employed. Maybe I was simply unable to hear these things. Yes, there were times when I thought I heard things, but they were subtle, and hard to repeat. Changing loudspeakers made huge differences. Changing recording companies or engineers made huge differences. But, the anticipated “dramatic” event of inverting polarity appeared to be missing, in spite of how appealing the idea of waveform integrity is from an engineering perspective.

(F. Toole).

A. Jones (another recognized by many as expert, assuming A. is Andrew)

One intriguing approach was pioneered by Bang & Olufsen (B&O), the “filler driver” concept. This was basically a conventional two-way speaker with a filler driver that corrected the phase error. Ingenious but just as flawed as the other approaches. Why flawed? Because all implementations of phase linear speakers other than those using concentric drivers achieve their phase linearity on only one axis. Every other angle, both horizontal and vertical, must introduce added differential delay and so eliminate phase coherency.

(A. Jones)

 

[TLS Guy]

Agreed to a point, at least in this case/topic, but it would have been to a much larger extent if he had gone into engineering, preferably electrical (or electrical and electronics, or measurements/instrumentation etc.) in those days, instead of medicine lol..

He, or we, can't convince guys like PaulBe, who clearly is on the subjective side, he emphasized the importance/relevance of subjective measurements, that I fully agreed, but on trying to establish what he experienced as reported in the last few threads on phase, I would put much more importance on any of such subjective measurements done in blind AB, at least single blind if not double blind. That of course is nearly impossible to do for home entertainment environment, even Harman would have difficulty doing it to Dr. Toole's satisfaction (I don't know that but can imagine it).

There is some threads on this very topic, below is one, and I would think the OP, if interested, might want to read it to see the tons of different opinions, many based on their own research/reading, and experience.

As to "experts" @TLS Guy , I don't know who he would consider expert, but if Dr. Toole is one he might consider as an expert, then he would probably be please to see that Dr. Toole and him might agree on this topic:

Linear Phase in Studio Monitors - the responses of Dr. Floyd Toole, Dr. Wolfgang Klippel, Andrew Jones, and James Croft | Audio Science Review (ASR) Forum

Here are a couple examples, noted/quoted by ASR members in the linked thread above:

Dr. Toole (again, just quoted by an ASR member, not sure if 100% accurate)


A. Jones (another recognized by many as expert, assuming A. is Andrew)

That is exactly the point I made. Even with two single stereo drivers there will be phase shifts as you move around the room.

 

[PaulBe]

Agreed to a point, at least in this case/topic, but it would have been to a much larger extent if he had gone into engineering, preferably electrical (or electrical and electronics, or measurements/instrumentation etc.) in those days, instead of medicine lol..

He, or we, can't convince guys like PaulBe, who clearly is on the subjective side, he emphasized the importance/relevance of subjective measurements, that I fully agreed, but on trying to establish what he experienced as reported in the last few threads on phase, I would put much more importance on any of such subjective measurements done in blind AB, at least single blind if not double blind. That of course is nearly impossible to do for home entertainment environment, even Harman would have difficulty doing it to Dr. Toole's satisfaction (I don't know that but can imagine it).

There is some threads on this very topic, below is one, and I would think the OP, if interested, might want to read it to see the tons of different opinions, many based on their own research/reading, and experience.

As to "experts" @TLS Guy , I don't know who he would consider expert, but if Dr. Toole is one he might consider as an expert, then he would probably be please to see that Dr. Toole and him might agree on this topic:

Linear Phase in Studio Monitors - the responses of Dr. Floyd Toole, Dr. Wolfgang Klippel, Andrew Jones, and James Croft | Audio Science Review (ASR) Forum

Here are a couple examples, noted/quoted by ASR members in the linked thread above:

Dr. Toole (again, just quoted by an ASR member, not sure if 100% accurate)


A. Jones (another recognized by many as expert, assuming A. is Andrew)

Perhaps I haven’t explained myself very well. I am not a subjectivist. Measurements matter. Measurements that we commonly depend on do not tell a whole story, and often become strawmen for argumentation by both objectivists and subjectivists. Why they become strawmen has various answers.

Floyd Toole did say – I’ll paraphrase it – ‘We do not listen in waveforms’. The reproduced sound does Not need to be waveform matched to the original source to achieve great reproduction. That is a good thing. Reproduction is an analogy.

Waveform matching from source to reproduction, and phase matching between reproducers, are two different subjects.

I declared that phase matching matters with correlated sound, and reproducers. This should be self-evident. We use the same speakers for L&R. The most coherent sound from L&R comes from speakers with matched drivers and matched crossovers. Any speaker pair – or combination - that produces a phantom image relies on reproducer matching to produce the best phantom image. This is the kind of thing that the BBC knew 50 years ago, and they are hardly subjectivists.

All multi-channel recordings made in acoustic space – especially those made with a Decca Tree style mic setup - have correlating signals between any combinations of the channels. We don’t need to lock our heads in a vice to hear these correctly. The Mic Tree is manipulated to the production requirements. Sound correlation between channels is also done with electronic sources and has been done since early 2 channel stereo.

Again, one does Not need to put their head in a vice, nor distance match their speakers to a millimeter, to hear the effect. However, sitting at MLP matters. There is only one good seat in a HT or home listening room. This has always been the case since 2 channel stereo. A phase matched HT system will reproduce recorded details that can’t be reproduced in common unmatched layouts.

The phantom image is very delicate. The speakers do Not have to be linear phase. They have to be as similar as possible to create that fragile phantom image. The image does not need source/reproduction waveform matching. It needs reproducer phase/waveform matching between speakers that produce a phantom image. On the production side, recording engineers will use matched microphones to best record stereo in an acoustic space.

The interesting thing is this lack of phase match is the kind of problem that room correction like Dirac tries to fix. They are partially successful.

I’m done with this topic.