Concert Hall sound

[gmgraves]

2 hours ago, phosphorein said:

 

I remember Whyte writing about this in Audio magazine and remember the Dead End being where the speakers were situated. I arranged my listening space based on Whyte's suggestion. My impression is that most mastering facilities are set up based on this concept.

Then I misremembered and that's all there is to it. 

[shtf]

17 hours ago, STC said:

 

You mentioned elsewhere that you are still chasing the elusive sound some 30 year ago that you accidently discovered. By now you should have known you are going the wrong direction. More than half of the sound that determines fidelity/realism is not even in the recording. It is the ambiance. Even with mp3 SQ you can make great sound if you address the room acoustics.

 

Where do you get this from?  Take your computer to your water closet and listen to the music in your first video again and then go sit in your backyard and listen once more and once again in your listening room. 

 

If the music in the video sounds even reasonbly different between locations then you just might have a point.  If not, then you're way off base regarding the significance of the listening room's acoustics and their contributions.

[fas42]

18 hours ago, STC said:

 

You mentioned elsewhere that you are still chasing the elusive sound some 30 year ago that you accidently discovered. By now you should have known you are going the wrong direction. More than half of the sound that determines fidelity/realism is not even in the recording. It is the ambiance. Even with mp3 SQ you can make great sound if you address the room acoustics.

 

There are a variety of reasons why I'm still "chasing" - and the main one of them is that the SQ that's possible is, yes, so elusive - at the moment.

 

Wrong direction? The amount of awful sound I've heard from ambitious systems over the years is pretty depressing - my interest is in trying to inject some sanity into the audio game, and move the thinking towards getting playback to, well, play back the recording with full integrity; rather that having rigs which are Yet Another Effects Unit.

 

The dilemma with producing high SQ is doing it with "robustness"; meaning, you can start a system from cold and after about 5 minutes, and irrespective of what's happening otherwise electrically nearby the setup will be performing to a high standard. I have never achieved this, because the raw ingredients, the components, aren't engineered well enough, or are far, far too expensive to consider playing tweaking games with - this is an absurd situation, and constant heckling by people like me on the sidelines is needed, until some more sense emerges.

[Fitzcaraldo215]

1 hour ago, shtf said:

 

Where do you get this from?  Take your computer to your water closet and listen to the music in your first video again and then go sit in your backyard and listen once more and once again in your listening room. 

 

If the music in the video sounds even reasonbly different between locations then you just might have a point.  If not, then you're way off base regarding the significance of the listening room's acoustics and their contributions.

Yes, he went way overboard in suggesting that MP3 could sound great with great room acoustics.  But, from much personal experience, it's clear that you are going to an opposite extreme.  Listening room acoustics absolutely affect the sound that we  hear in major ways.  There is so much empirical science to back this up, I don't even begin to know where to direct you for starters.

[Fitzcaraldo215]

15 minutes ago, fas42 said:

 

 

Wrong direction? The amount of awful sound I've heard from ambitious systems over the years is pretty depressing - my interest is in trying to inject some sanity into the audio game, and move the thinking towards getting playback to, well, play back the recording with full integrity; rather that having rigs which are Yet Another Effects Unit.

 

Yes, Frank, you are definitely the voice of sanity in the audio game.

[fas42]

6 hours ago, Fitzcaraldo215 said:

Yes, phantom imaging between two speakers becomes more accurate as the apparent, panned sound source approaches the speaker to one side or the other.  Also, the centered phantom image between two speakers with a 60 degree angle between them will be less accurately conveyed than if the angle was 30 degrees.  

 

There is also a special case of sounds from front dead center and slightly either side of that.  Due to our head related transfer function and ears to the sides of our head, there is a large drop at upper middle frequencies when heard from phantom imaging by two front speakers.  The same signal when played by a single center channel speaker eliminates that.  That is important for imaging at the front of the soundstage for music, and also for dialog articulation on video.  It is a frequency response problem with center imaging in stereo we have just gotten used to.

 

 

Probably the most remarkable phantom imaging that our ear/brains can do is with a true mono source being played over stereo speakers - identical signal from the two speakers. This produces an image which always remains perfectly in front of one, "follows you" as you move from between the speakers to the left of the left speaker, and all the way back to the right of the right speaker.

 

This can only happen when the setup is producing competent sound; anything less than that level of SQ and the sound "jumps back into" the nearest speaker as one moves sideways; which is of course what one gets with normal reproduction.

[fas42]

12 minutes ago, Fitzcaraldo215 said:

Listening room acoustics absolutely affect the sound that we  hear in major ways.  There is so much empirical science to back this up, I don't even begin to know where to direct you for starters.

 

The empirical science has always used playback systems that weren't of sufficient standard - "In the 1930's scientists tried to fly faster than the speed of sound, using every aircraft that was readily available - and failed. They confidentally stated, 'It's impossible to break the sound barrier, because we have tested for that possibility' ".

[Fitzcaraldo215]

2 minutes ago, fas42 said:

 

The empirical science has always used playback systems that weren't of sufficient standard - "In the 1930's scientists tried to fly faster than the speed of sound, using every aircraft that was readily available - and failed. They confidentally stated, 'It's impossible to break the sound barrier, because we have tested for that possibility' ".

Ah, I see.  The problem is they were not using a Franknfas-approroved system in their testing.

 

I have a better idea, though.  Instead of wasting your time on trivial playthings like audio, why no go and show them how to cure cancer.  There is Nobel Prize in it for you.  I am sure you have what it takes.

[fas42]

Sarcasm doesn't achieve anything ... there are plenty of people around who have discovered, or investigated aspects of what I'm talking about - I have pointed to them from time to time. But most of these people largely keep their heads down, and go along with the crowd - to keep the peace ... I'm pissed off that audio is still in the doldrums, and just doing a bit more to push this message than others.

[kumakuma]

8 minutes ago, fas42 said:

I'm pissed off that audio is still in the doldrums...

 

Is it?

[STC]

9 hours ago, gmgraves said:

That's the way I recall it. Of course, it's been close on to 40 years and human memory is quite fallible about details like that. I'm not insisting I'm right, but if I am wrong about Bert's LEDE arrangement, you can't prove it by me. I can ask Gene Pitts when next I speak to him (he was the Editor-in-Chief of Audio magazine for the last 20 years or so of it's life), he might remember more clearly, after all he interfaced with Bert a lot, while I just visited his house once.

 

gmgraves, you didn't just repeat an event more than 40 years ago but also provided a detailed description of the venue to justice your thoughts on this subject matter. Given your vast experience in recordings you should have know the sound as described, and I quote you

 

Quote

I heard something similar to this years ago at Bert Whyte's* house. He had constructed a dedicated listening room in what he called "live end, dead end" His custom speakers were arranged  at the live end of the room which was highly reflective with hard, irregular surfaces. His listening chairs were at the dead end of the room in which every building surface was covered in acoustic insulation five inches thick with a tasteful light tan grill cloth material covering the insulation. I have never heard such pinpoint imaging and such a bloom of acoustical space. Of course

 

cannot be correct. That will never work. 

 

Just to clarify,  here is a detailed description of his room which also confirms to what I have been saying all along.

 

Since that time, several hi-fi enthusiasts have installed 
live-end, dead-end listening rooms in their homes. Most 
notable among them is the associate editor of Audio Magazme, 
Bert Whyte. Both he and Mr. Lockhart have said that when 
they play records now for their friends and associates, no one 
can believe their ears. It seems reasonable that symphonic 
music, in particular, should sound better in this environment 
as it allows you to hear the acoustics of the hall in which the 
music was recorded, rather than the acoustics of your own 
listening room. 

 

and here from Stereophile

 

Quote

The best, most helpful listening environment known to me is the full live-end/dead-end treatment where the speaker end is as acoustically dead as possible, covers perhaps the first third of the room, then gives way to a very reflective live end equipped with diffusors and virtually no absorptive components. This means damping walls, floors, and ceiling with 3" to 4" of linearly absorptive material such as Sonex. In a pinch, a heavy rug will do for floor damping, but elsewhere, make it thick, and make it dead! And no furniture or equipment racks between, behind, beside, or close in front of the speakers---all this stuff goes in the live end. Among reviewers of my acquaintance, Audio's longtime Associate Editors Bert Whyte and Barney Pisha [both now deceased.---Ed.] share the prize for best listening room. Bert's was one of the first residential LEDE rooms in the country (constructed in 1980), a good 25'-long rectangular space on a concrete slab (concrete on mother earth is best for floors; anything less rigid becomes a sounding board for the music). Barney's listening room, much smaller than the pictures published recently in Audio would suggest, is a calibrated LEDE environment complete with elaborate diffusors in the live end.
Read more at https://www.stereophile.com/features/38/index.html#Hi2ywlCmGCESk2sh.99

 

Misinformation is what's killing real high fidelity and encourages snake oil.

[fas42]

12 minutes ago, kumakuma said:

 

Is it?

 

I agree that standards are slowly rising - excellent value for money equipment is around; careful buying will get one a setup that gets so much right in the first instance.

 

Audio shows and retail outlets are the giveaway - the former will be full of expensive equipment that will sound 'orrible, with just a couple of rigs showing good potential - if a car show was full of duds that were dreadful or outright dangerous to drive, how much respect would vistors have for the manufacturers, etc.

 

Last time I visited an ambitious audio dealer, everything sounded terrible - I was shaking my head after leaving the store.

[STC]

8 hours ago, Fitzcaraldo215 said:

Yes, phantom imaging between two speakers becomes more accurate as the apparent, panned sound source approaches the speaker to one side or the other.  Also, the centered phantom image between two speakers with a 60 degree angle between them will be less accurately conveyed than if the angle was 30 degrees.  

 

There is also a special case of sounds from front dead center and slightly either side of that.  Due to our head related transfer function and ears to the sides of our head, there is a large drop at upper middle frequencies when heard from phantom imaging by two front speakers.  The same signal when played by a single center channel speaker eliminates that.  That is important for imaging at the front of the soundstage for music, and also for dialog articulation on video.  It is a frequency response problem with center imaging in stereo we have just gotten used to.

 

I think all  this is in Toole's latest book: Volume 3 of Sound Reproduction.  But, phantom imaging is obviously vitally important to stereo and all forms of Mch.  They would not work adequately without it.  I also believe that phantom imaging, imprecise though it may be,  can be perfectly adequate to convey the diffuse reflected and reverberant sounds from Mch surround channels.  That is, I think, why Toole believes adding surround channels requires a huge increase in channel count in order to make much perceivable difference.  Adding height speakers is a different matter because that is adding additional location and dimensional information in the Z-direction.

 

Incidentally, Toole is a big fan of Mch sound.

 

I also disagree with you about what signal is present in Mch surround speakers on recordings.  I will go through it again.  In a simple Mch mic setup, there are stage mics for the front channels plus more distant hall mics, usually omnis, for surround channels.  Focus on one of those distant mics for a moment.  Imagine sitting where one of those mics is.  What will they pick up?  Obviously, they will pick up much reflected hall sound, given their location.  But, there is no way to block them from picking up or to suppress the direct sound from the stage at that more distant perspective.  Ergo, they contain signal that is an inseparable combination of reflected hall sound plus that more distant direct sound from the stage, just as you would hear if sitting there.  That direct sound component cannot be erased, nullified or removed from the signal via editing, mastering, etc. 

 

On playback, that combined direct plus reflected signal from the distant mic goes to a surround channel.  It reproduces the desired hall ambience picked up from hall reflections.  But, that direct sound is also there, delayed, somewhat down in level, and altered somewhat in frequency response relative to the front main and center channels by air/distance attenuation.  But, it interacts with the sound from the main channels, producing a phantom image mainly in the front to rear direction into the room.  The diffuse reflected energy component in the surround channel does that, too, but to a lesser degree.  

 

That phantom image of the direct sound from front and surround speakers is closer to the front speakers, because the front channels are somewhat louder, having been recorded closer to the performers.  This is why I hear the sound being "pulled into the room" in front of the front speaker plane in a way stereo does not do.  It is also why I find that discrete Mch provides a greater apparent depth of the frontal soundstage.

 

Oversimplified, that is what I believe is going on in Mch.  It also exactly reflects what I hear when I listen to the signal from surround channels in discretely recorded Mch - diffuse reflected sound plus direct sound from the stage.  And, properly done, it works.   I think it is the best approach yet to recording and reproducing a successful illusion of live music in the concert hall.

 

 

 

Quote

Yes, phantom imaging between two speakers becomes more accurate as the apparent, panned sound source approaches the speaker to one side or the other.  Also, the centered phantom image between two speakers with a 60 degree angle between them will be less accurately conveyed than if the angle was 30 degrees.  

 

Ok. Agree. That's why my two speakers are kissing each other with just about 3cm apart.  

 

There is also a special case of sounds from front dead center and slightly either side of that.  Due to our head related transfer function and ears to the sides of our head, there is a large drop at upper middle frequencies when heard from phantom imaging by two front speakers.  The same signal when played by a single center channel speaker eliminates that.  That is important for imaging at the front of the soundstage for music, and also for dialog articulation on video.  It is a frequency response problem with center imaging in stereo we have just gotten used to

...

 

[ Somehow, rest of the text gone missing...I will continue later.]

 

[STC]

9 hours ago, Fitzcaraldo215 said:

I also disagree with you about what signal is present in Mch surround speakers on recordings.  I will go through it again.  In a simple Mch mic setup, there are stage mics for the front channels plus more distant hall mics, usually omnis, for surround channels.  Focus on one of those distant mics for a moment.  Imagine sitting where one of those mics is.  What will they pick up?  Obviously, they will pick up much reflected hall sound, given their location.  But, there is no way to block them from picking up or to suppress the direct sound from the stage at that more distant perspective.  Ergo, they contain signal that is an inseparable combination of reflected hall sound plus that more distant direct sound from the stage, just as you would hear if sitting there.  That direct sound component cannot be erased, nullified or removed from the signal via editing, mastering, etc. 

 

On playback, that combined direct plus reflected signal from the distant mic goes to a surround channel.  It reproduces the desired hall ambience picked up from hall reflections.  But, that direct sound is also there, delayed, somewhat down in level, and altered somewhat in frequency response relative to the front main and center channels by air/distance attenuation.  But, it interacts with the sound from the main channels, producing a phantom image mainly in the front to rear direction into the room.  The diffuse reflected energy component in the surround channel does that, too, but to a lesser degree.  

 

cont/..

 

The sound that will be picked up by the rear microphone will consist of :-

 

1) Direct sound

2) 1st reflection

3) Reverberation.

 

In general these three combination varies according to the nature of walls reflection/absorption, distance from the source and the type of instrument (frequency response) of the direct sound. In last few year, the digital technology has advanced so much that it is now possible to isolate the the ambiance from the direct sound. Anyway, that's another topic altogether.

 

Theoretically, how the sound will shape at the position of the microphone can be recreated by using impulse response of the particular location of the hall. How it is going to sound depends on the hall's impulse response which can be used to recreate the reflection from that angle.  Going back to your post, the direct sound is already in the front left and right channel. The other elements of the sound can be created by the impulse response of the concert hall.  In multichannels, the rear hall sound is recorded by a microphone with the intended playback angle is around 110 degrees. Don't you think if you have another 12 channels of the rear channels that will be more accurate than the one meant for speakers placed at 110 degrees only?

 

Furthermore, a hall's acoustics characteristic is made of the three elements mentioned above varies from hall to hall.  In a bigger hall the 1st or early reflection could arrive after 40ms. In another hall it could arrive in just 15ms. The late reflection (reverberation) could be arriving after 80 ms to 300ms depending on the hall. These difference accounts for the difference experience in sound of different concert halls. Furthermore, concert hall goers would by now would have certain halls suites better for certain type of music due to the difference in the 3 elements of the concert halls.

 

1) 5.1 > 2.0

 

2) 2.0 with 30 over channels of rear/side ambiance > than 5.1

 

3) 5.1 with over 30 over channels of rear/side ambiance >  2.0 with 30 over channels of rear/side ambiance

 

to cont/...

 

 

 

 

[shtf]

3 hours ago, Fitzcaraldo215 said:

Yes, he went way overboard in suggesting that MP3 could sound great with great room acoustics.  But, from much personal experience, it's clear that you are going to an opposite extreme.  Listening room acoustics absolutely affect the sound that we  hear in major ways.  There is so much empirical science to back this up, I don't even begin to know where to direct you for starters.

 

I should clarify a bit.  A listening room’s acoustics do have some limited effect on playback sound via it’s dimensions, etc, but there is a quite an impact depending on the speakers’ inferior or superior placement within the room.

 

More specifically, I was implying that listening room acoustic treatments are of little value – provided the listening room itself is deemed reasonable enough – i.e. lacking serious room deficiencies and/or absurdities.

 

But I’m curious.  Aside from a speaker’s superior placement within a given already reasonable room, what are some of these “major” ways a room’s acoustics impact the sound we hear?

[fas42]

I enter "audio hell" via two missteps - i don't care about the room; and, I plunk the speakers down wherever it's most convenient to put them, where they will be the least nuisance ... burn, son, burn!!

[gmgraves]

3 hours ago, STC said:

 

gmgraves, you didn't just repeat an event more than 40 years ago but also provided a detailed description of the venue to justice your thoughts on this subject matter. Given your vast experience in recordings you should have know the sound as described, and I quote you

 

 

cannot be correct. That will never work. 

 

Just to clarify,  here is a detailed description of his room which also confirms to what I have been saying all along.

 

Since that time, several hi-fi enthusiasts have installed 
live-end, dead-end listening rooms in their homes. Most 
notable among them is the associate editor of Audio Magazme, 
Bert Whyte. Both he and Mr. Lockhart have said that when 
they play records now for their friends and associates, no one 
can believe their ears. It seems reasonable that symphonic 
music, in particular, should sound better in this environment 
as it allows you to hear the acoustics of the hall in which the 
music was recorded, rather than the acoustics of your own 
listening room. 

 

and here from Stereophile

 

 

Misinformation is what's killing real high fidelity and encourages snake oil.

I think I already agreed that I mis-remembered. Why the Spanish Inquisition?

[STC]

1 hour ago, shtf said:

 

Where do you get this from?  Take your computer to your water closet and listen to the music in your first video again and then go sit in your backyard and listen once more and once again in your listening room. 

 

If the music in the video sounds even reasonbly different between locations then you just might have a point.  If not, then you're way off base regarding the significance of the listening room's acoustics and their contributions.

 

Do you know what is near field listening?  Depends on the distance from the source, it can sound different or almost similar but I am confident that I will pass the DBT if I have to distinguish the two location. But if you take the nearfield example to the extreme than the headphone will sound identical in the two locations. 

 

 

[STC]

17 minutes ago, gmgraves said:

I think I already agreed that I mis-remembered. Why the Spanish Inquisition?

 

Oh.I didn't see your reply to phosperin. 

[semente]

3 hours ago, shtf said:

 

I should clarify a bit.  A listening room’s acoustics do have some limited effect on playback sound via it’s dimensions, etc, but there is a quite an impact depending on the speakers’ inferior or superior placement within the room.

 

More specifically, I was implying that listening room acoustic treatments are of little value – provided the listening room itself is deemed reasonable enough – i.e. lacking serious room deficiencies and/or absurdities.

 

But I’m curious.  Aside from a speaker’s superior placement within a given already reasonable room, what are some of these “major” ways a room’s acoustics impact the sound we hear?

 

Rooms dimensions affect frequencies below ~300Hz (resonances), room surfaces (and also those of the furnishings) affect frequencies above that (reflections).

http://realtraps.com/art_basics.htm

[Fitzcaraldo215]

13 hours ago, shtf said:

 

I should clarify a bit.  A listening room’s acoustics do have some limited effect on playback sound via it’s dimensions, etc, but there is a quite an impact depending on the speakers’ inferior or superior placement within the room.

 

More specifically, I was implying that listening room acoustic treatments are of little value – provided the listening room itself is deemed reasonable enough – i.e. lacking serious room deficiencies and/or absurdities.

 

But I’m curious.  Aside from a speaker’s superior placement within a given already reasonable room, what are some of these “major” ways a room’s acoustics impact the sound we hear?

Room acoustics is a complex subject.  Again, in recent readings, I highly recommend Toole's Sound Reproduction V3, which also goes into many aspects of speaker performance, etc.

 

The  major influence of the room is in the bass due to modes Induced by reflections based on room dimensions, construction, materials and speaker placement.  It is virtually impossible to design a listening room of typical size that is not influenced by these modes, though their magnitude might be partially mitigated somewhat by room design.  

 

I have measured several "good" rooms, one used by a music and equipment reviewer.  Modal variations were in the range of +- 8 to over +- 20 dB. That is quite a major impact that would not be tolerated in a speaker or in audio electronics. These were cleaned up nicely by the application of DSP EQ, much to the satisfaction of all listeners.  Yes, I agree, bass modes of this magnitude are very difficult to control via passive absorption, especially below 100 Hz.  

 

Above the Scroeder or Transition frequency of typically 300-500 Hz, the room reflections typically play less of a role and the speaker predominates.  But, early reflections due to speaker placement or highly reflective materials, like glass, can still cause frequency response issues, as can speakers without a fairly uniform directivity index.

 

The real point is reflections play a natural and inseparable part in sound as we hear it. They alter the sound and have a large effect on the sound we perceive. That is true in the concert hall and in the listening room.  But, listeners are generally unaware of them as their consciousness is preoccupied by the direct sound from the stage or from their speakers, as well as the sight cues from those sound sources.  Some listeners therefore don't believe reflections are significant, but they would be wrong in that.

 

 

[gmgraves]

16 hours ago, fas42 said:

 

The empirical science has always used playback systems that weren't of sufficient standard - "In the 1930's scientists tried to fly faster than the speed of sound, using every aircraft that was readily available - and failed. They confidentally stated, 'It's impossible to break the sound barrier, because we have tested for that possibility' ".

Now, Frank, that's a bit of an exaggeration. Nobody in the 1930's actually tried to fly faster than sound because there was no technology powerful enough to get aircraft past 400 MPH. The fastest aircraft in those years were various air races and the race planes could barely hit 400 MPH by the time WWII came along. During the war, fighter pilots on both sides reported that their aircraft started to shake violently in a high-speed dive and some even reported a condition known as "reverse aileron" where pushing the stick forward made the nose go up rather than down as it should. These pilots were approaching the speed of sound and the aerodynamics of their fighter aircraft were such that the planes didn't like that speed at all. and the pilots were terrified. Aerodynamic engineers dubbed the speed of sound as the "Sound Barrier" and actually thought that it could not be approached without destroying the plane and killing the pilot. The end of the war and the German V2 rocket showed that a self propelled machine could, indeed, survive the "sound barrier" in one piece and plans were being made to make a machine that could possibly go fast enough to to achieve supersonic flight. Here in the USA, Bell Aircraft experimented with rocket-powered machines while in England, De Havilland aircraft was working with Frank Whittle's radial turbojet engines to provide the necessary thrust on it's DH-108. De Havilland dropped out when the founder's son Geoffrey was killed testing the plane that was going to make the British attempt. In America, the Bell X1 was flown by WWII fighter ace Chuck Yeager. He officially broke the sound barrier on October 14, 1947. There is some evidence that a US Air Force pilot named George Welch unofficially broke Mach 1 in an XP-86 (later called the F-86) on the first of October of that year (beating Yeager) but it went unverified.

[semente]

1 hour ago, Fitzcaraldo215 said:

Modal variations were in the range of +- 8 to over +- 20 dB.

 

That's wild. What was the smoothing used for plotting that measurement?

[semente]

1 hour ago, Fitzcaraldo215 said:

The real point is reflections play a natural and inseparable part in sound as we hear it. They alter the sound and have a large effect on the sound we perceive. That is true in the concert hall and in the listening room.  But, listeners are generally unaware of them as their consciousness is preoccupied by the direct sound from the stage or from their speakers, as well as the sight cues from those sound sources.  Some listeners therefore don't believe reflections are significant, but they would be wrong in that.

 

In my opinion and understanding, one cannot put live and reproduced in the same bag.

 

In a live performance, say a piano recital, there's a sound source, a room with a particular acoustic signature and a listening spot where both direct and reflected sound arrives.

 

In reproduction, we wish to accurately recreate a soundfield, roughly similar to what the listener would have experienced, picked up by a mic onto two-channel stereo (to make things easier).

Since both direct and refelected sound will be reproduced from the same spot, the original soundfield cannot be recreated.

But, to accurately reproduce the signal one should as @gmgraves mentioned position the system in a dead or near-anechoic environment; otherwise the listening room's own reflections of the reproduced sound will add a layer of confusion which will probably affect tonal balance as much as imaging.

Cinema rooms, which unlike performance rooms are also used for reprodcution, have a lot of absorbtion built into their walls.

 

People may prefer, and many do, room reflections but this is a matter of taste and perception, not of accuracy. Listening room reflections are not cues of the original event ambience. But they enhance the soundstage-effect or 3D-ness by creating phantom images: phantom images.pdf

[Fitzcaraldo215]

13 minutes ago, semente said:

 

That's wild. What was the smoothing used for plotting that measurement?

That was at 6 dB per octave.  Likely it would have been greater with less smoothing.

 

Wild?  From what I have seen in Toole's book and numerous times elsewhere, it is quite typical.  But, amazingly, people just don't know unless they measure.  And, when they hear it cleaned up via DSP, they love the result.