Measurements & Sound Quality

[Ralf11]

Frank, you are the Deepak Chopra of audio

[sandyk]

27 minutes ago, STC said:

Unless you are discussing this with sound from headphones,

 

Yes, I was discussing it with sound from headphones, and with different S/W doing the .aiff to .wav conversion at Soundkeeper.

 Yes, there was one particular software version that " got out of the way " better too..

[PeterSt]

1 hour ago, Ralf11 said:

Frank, you are the Deepak Chopra of audio

 

In Australia ?

 

[GregWormald]

5 hours ago, sandyk said:

How can they ever be truly " lifelike" while using ONLY 2 front stereo speakers , which the vast majority of Audio systems do ?

 

Maybe "better than "lifelike"" if the venue detracts from the music rather than adds to it.

[jabbr]

10 hours ago, sandyk said:

 

 How can they ever be truly " lifelike" while using ONLY 2 front stereo speakers , which the vast majority of Audio systems do ?

 

My statement makes no such assumptions, nor is dependent on a particular number of speakers, particular file format, particular power supply, particular type of cable nor any other detail. I said that until we understand what is not adequately reproduced, then we cannot measure the difference between any actual system and an ideal reproduction system — the failing is not in the ability to measure but knowing what to measure.

[jabbr]

6 hours ago, GregWormald said:

 

Maybe "better than "lifelike"" if the venue detracts from the music rather than adds to it.

 

“Better than lifelike” is a purely subjective experience. There is no need to measure, just listen to what you like!

[Kal Rubinson]

11 hours ago, fas42 said:

This is how one advances the "art" - accepting a compromise simply because that's as good as one can get with the current situation, and personal knowlege, is not a useful solution.

Stereo is a compromise.

[sandyk]

7 hours ago, jabbr said:

 

My statement makes no such assumptions, nor is dependent on a particular number of speakers, particular file format, particular power supply, particular type of cable nor any other detail. I said that until we understand what is not adequately reproduced, then we cannot measure the difference between any actual system and an ideal reproduction system — the failing is not in the ability to measure but knowing what to measure.

Jon

 I don't have a problem with what you are saying, but realistically, I doubt that this will ever be achieved in the immediate future, especially with the current industry attitude as shown by dumbing down Audio with MQA to make a few more company balance sheets look healthier, and sell more of the same older material yet again.

 

Alex

[fas42]

7 hours ago, jabbr said:

 

My statement makes no such assumptions, nor is dependent on a particular number of speakers, particular file format, particular power supply, particular type of cable nor any other detail. I said that until we understand what is not adequately reproduced, then we cannot measure the difference between any actual system and an ideal reproduction system — the failing is not in the ability to measure but knowing what to measure.

 

What is usually inadequately reproduced is the fine detail; technically it may be all or largely there, but it is too distorted or masked by inadequacies of the playback chain - the listening brain either can't make sense of it, and then it just sounds a mess; or it is too stressful for our minds to untangle, and listener fatigue builds very quickly.

 

Objectively measuring this behaviour is not going to be easy, because it's 'buried' amongst the obvious, high level sound elements. And you can't just measure the behaviour of a low level track by itself, because the misbehaviour is due in large part from the presence of the high level content - it's a form of intermodulation distortion.

 

The listening mind has no trouble distinguishing an 'ideal', from conventional quality - all the usual adjectives and phrases immediately spring to mind; effortless, organic, natural, immersive, holographic, "you are there", "an open window", etc, etc.

[fas42]

Chopra? He was a bright boy, knew his endocrinology as well as anyone, but got buried in the spiral of modern living - "drinking black coffee by the hour and smoking at least a pack of cigarettes a day". Becoming aware of an alternative outlook, he vigorously pursued it, because he had an energetic mind ... not such a bad comparision, perhaps.

[fas42]

5 hours ago, Kal Rubinson said:

Stereo is a compromise.

 

Maybe a compromise, but can deliver remarkably impressive experiences, if the equipment used is up to it. Most people have at least once or twice come across a stereo rig "that blew their mind" - that shows what's possible, when all the usual compromises are absent.

[bluesman]

6 hours ago, Kal Rubinson said:

Stereo is a compromise.

All reproduced music is a compromise - I've never heard a playback that was truly indistinguishable from a live performance.  I've always believed that this is because intermodulation among all notes from all instruments being played is captured in every recording as part of the source waveform.  During playback, the original "natural" IM is created again, so there's twice as much being played back as was generated in the original performance.  And it's now intermodulating anew with the source signal to generate yet more audible energy that wasn't present in the performance.  I strongly suspect that this is what throws a sonic "veil" over all reproduced music and what keeps it from sounding truly live.

 

If you record a simple C major triad played on a perfectly tuned piano with the pedals up to damp the other strings, a spectrum analysis of playback will show a lot of energy at frequencies other than 262, 330, and 392 Hz (middle C plus E and G above it). Add the sums and differences of each combination of those 3 (62, 68, 130, 592, 624, and 722) to their own natural harmonics, and you already have a rich sonic stew in which many of the "ingredients" are not in the recipe and were never added by the chef. Any IM distortion added by the devices through which the signal passes on its way from source to sound is miniscule by comparison and, at least to me, immaterial because it's truly inaudible.

 

Then throw in phasing.  All of the harmonics and intermodulation products from a single instrument are produced with phase relationships determined almost entirely by the instrument and its player.  But the same C major triad created by almost simultaneous striking of 3 sets of piano strings by 3 hammers then passes through devices that add frequency-dependent phase shifts before throwing it back out at you as separate notes from multiple drivers, none of which has the radiation pattern of a piano.  It's not the same triad any more, and we haven't even started to throw in the environmental factors.

 

So I certainly agree that stereo is a compromise - but the entire process of recording and playing back music is a compromise in which the basic limitations seem to have no current solution.  The fact that so many systems are so good is a minor miracle

[fas42]

32 minutes ago, bluesman said:

All reproduced music is a compromise - I've never heard a playback that was truly indistinguishable from a live performance.  I've always believed that this is because intermodulation among all notes from all instruments being played is captured in every recording as part of the source waveform.  During playback, the original "natural" IM is created again, so there's twice as much being played back as was generated in the original performance.  And it's now intermodulating anew with the source signal to generate yet more audible energy that wasn't present in the performance.  I strongly suspect that this is what throws a sonic "veil" over all reproduced music and what keeps it from sounding truly live.

 

Disagree. That "sonic veil" can be completely eliminated - because it's an artifact of the playback chain not behaving sufficiently well.

 

Typically, a rig below par will project that sonic veil; then, there's an abrupt transition in the subjective perception when the rig rises above the necessary level; whichever way the latter is achieved. Everything "snaps into focus" - this is a good phrase to use, because it's like using powerful binoculars without understanding how to stabilise on what you're pointing at, and how to fine tune the optics settings; until you get this exactly right it's an exercise in frustration, with bad blurring completely ruining the point of using a large zoom.

[Ralf11]

8 hours ago, jabbr said:

...until we understand what is not adequately reproduced, then we cannot measure the difference between any actual system and an ideal reproduction system — the failing is not in the ability to measure but knowing what to measure.

 

I have a voltmeter - what should I measure?

[jabbr]

10 minutes ago, Ralf11 said:

 

I have a voltmeter - what should I measure?

Volts  

[mansr]

Just now, jabbr said:

Volts  

No, that's what he can measure.

[STC]

1 hour ago, bluesman said:

All reproduced music is a compromise - I've never heard a playback that was truly indistinguishable from a live performance.  I've always believed that this is because intermodulation among all notes from all instruments being played is captured in every recording as part of the source waveform.  During playback, the original "natural" IM is created again, so there's twice as much being played back as was generated in the original performance.  And it's now intermodulating anew with the source signal to generate yet more audible energy that wasn't present in the performance.  I strongly suspect that this is what throws a sonic "veil" over all reproduced music and what keeps it from sounding truly live.

 

In reproduced music (using stereo) we are recreating 1) the sound and 2) the position of the sound.

 

As far as to the accuracy of reproducing a single sound via a transducer, we achieved the threshold a long time ago where a recorded sound could convince animals whose survival depends on the ability to distinguish an extremely small difference in the sound which is beyond human capability. You can find research papers with spectrograms of real and recorded sound that were used in their studies.

 

In one such experiment where the scientists wanted to know how the parent penguin could identify their chicks among thousands of other chicks relied on a single transducer and managed to fool the parent thinking that they were their chicks call.

 

The real problem with reproduced music is creating the position of the instruments. In live performance (unamplified) we could locate the source based on HRTF. With stereo, to recreate the positional cues of different instruments it only uses one of the HRTF cues to recreate a phantom image. This is the difference between live and playback. Real image (position) is just one spot for each source in the live performance. However, with music, the phantom image is created by two speakers. The brain is continuously locating two sources to create a single phantom image. The process is contradicting how real sound in nature behaves and therefore itself is unnatural There is no way during playback of two speakers to recreate the soundfield or soundstage will ever be natural to us unless each instruments sound is confined to a single speaker.
 

Here is the video of the competing chicks call. The parent could reach them among thousands of calls. Initially, scientists thought the penguins uses some sort of physical landscape marking to identify the chicks location.

 

 

 

[esldude]

15 minutes ago, STC said:

There is no way during playback of two speakers to recreate the soundfield or soundstage will ever be natural to us unless each instruments sound is confined to a single speaker.

Yep that will work.  I've done this using 5 musicians close miked in a damped environment.  Then play back over 5 speakers.  It can have a sound that is very real.  It sounds real in your room, not so much real like where it was recorded. 

[fas42]

10 minutes ago, STC said:

The real problem with reproduced music is creating the position of the instruments. In live performance (unamplified) we could locate the source based on HRTF. With stereo, to recreate the positional cues of different instruments it only uses one of the HRTF cues to recreate a phantom image. This is the difference between live and playback. Real image (position) is just one spot for each source in the live performance. However, with music, the phantom image is created by two speakers. The brain is continuously locating two sources to create a single phantom image. The process is contradicting how real sound in nature behaves and therefore itself is unnatural There is no way during playback of two speakers to recreate the soundfield or soundstage will ever be natural to us unless each instruments sound is confined to a single speaker.

 

 

 

IOW, if we were to listen to live sound on the other of a wall, where there were only two openings to the other side, mimicing the positioning of stereo speakers, it would sound just like a hifi system! Of course, no-one has done this sort of experiment; because it might expose an Inconvenient Truth ...

[STC]

27 minutes ago, fas42 said:

 

IOW, if we were to listen to live sound on the other of a wall, where there were only two openings to the other side, mimicing the positioning of stereo speakers, it would sound just like a hifi system! Of course, no-one has done this sort of experiment; because it might expose an Inconvenient Truth ...

 

 

You have mentioned this many times and if this is how a high fidelity system should sound like than I am (and probably most of us) wasted our money and time.

 

The sound that is going to come out of two openings is the sum of all sound in the room exiting through the small opening. The ambience cues are now directionally wrong. No recording will have such amount of ambience in their recordings as that would make the sound lack clarity. The closest analogy would be standing at your windows and listen to the traffic. As you close the window, the sound texture and intensity will change. They are hardly the same.

[diecaster]

47 minutes ago, fas42 said:

 

IOW, if we were to listen to live sound on the other of a wall, where there were only two openings to the other side, mimicing the positioning of stereo speakers, it would sound just like a hifi system! Of course, no-one has done this sort of experiment; because it might expose an Inconvenient Truth ...

 

No, it wouldn’t. How could you think this?

[bluesman]

44 minutes ago, esldude said:

Yep that will work.  I've done this using 5 musicians close miked in a damped environment.  Then play back over 5 speakers.  It can have a sound that is very real.  It sounds real in your room, not so much real like where it was recorded. 

Isolating the instruments greatly reduces intermodulation between & among them, and a damped environment further reduces extraneous input from resonance etc. Playing each individual instrument, closely miked for recording to minimize bleeding, through its own speaker is the best way I know of to prevent intermodulation from contaminating the recording. It's closer to having the individual instruments in the playback setting.  That's why it sounds more like real instruments, but in the playback environment rather than the recording setting.

[Ralf11]

can you make a vibrating string come out of small metal dome?

[fas42]

The point is, what would it sound like? Because, that's largely what two microphones set up in the same position would 'see'.

 

STC feels that it would have a lack of clarity - I'm concerned with the realism of the sound; if you were to stand before a open door into a room where live music was being played, would it sound 'fake'? Now, replace that single door with two smaller doors, spread apart ... get my drift?

 

 

[jabbr]

3 hours ago, mansr said:

No, that's what he can measure.

If we also get him an ohmmeter then he can measure everything