Recording Methods and Fidelity

[gmgraves]

This is the perfect reply.

 

Stereo is actually an illusion, but one that is necessary if you wish to recreate the sound of an instrument playing in a resonant space.

Most pop and rock recordings don't have any spacial information to begin with, it's all fabricated in post-processing.

 

If you wish to create the impression of having musicians playing in your room then you'll have to do as Acoustic Research did.

Record each instrument individually in an anechoic environment with a single microphone and playback echo instrument through it's own speaker.

 

R

 

 

Stereo is merely the way that one captures, in three dimensions, the space that a musical ensemble occupies while playing. This notion that one can capture the individual instruments and then arrange them in their approximate locations for proper playback is wrong-headed but more importantly, it's NOT stereophonic sound, it's multi-channel monaural sound.

[Jud]

Oh, so you are that guy.

 

Uh-huh.

[Sal1950]

In my opinion and experience the best way to recreate the venue ambience and instrument positioning registered in the recording is done by reducing the playback-room contribution as much as possible (I'm speaking of recordings of live un-amplified music with minimal mic setups).

This means aiming the speakers at the listening point and listening as close to the speakers as possible (allowing just enough distance for the dispersion patterns of the drivers to integrate).

Besides listening near field, it is also convenient to use speakers with controlled directivity, exhibiting a progressive off-axis response attenuation in the upper-midrange and above such as that of the following examples:

Horns, waveguides and wide baffles generally produce this kind of dispersion pattern.

 

R

 

Definitely a recipe for for building a system with superb imaging!

I used Klipsch LaScala's for 30+ years. Out in the room about 5 feet off the front wall and 4 feet off the side walls. Aimed to cross over just slightly in from of the listening chair which was about 7 feet from the speakers and same from the rear wall. Being driven by VTL tube Compact monoblocks in a room fairly well damped with natural objects of drapes, carpets, and furnishings. This system was capable of creating a soundstage as good as I've ever heard, scary and uncanny could be the illusion in a darkened room With appropriate recordings the image could be pinpoint accurate placing instruments from side wall to side wall, and from the rear wall to a few feet in front of the speakers.

I badly miss that system but couldn't fit 1/6 of it in my current retirement digs. ;(

 

Really makes me giggle when I hear the guys speak of soundstaging with their headphones. IMHO there just isn't such a thing.

[esldude]

Stereo is merely the way that one captures, in three dimensions, the space that a musical ensemble occupies while playing. This notion that one can capture the individual instruments and then arrange them in their approximate locations for proper playback is wrong-headed but more importantly, it's NOT stereophonic sound, it's multi-channel monaural sound.

 

I don't know that it is wrong headed. It is highly impractical. It is multi-channel mono. Now such a thing would be ridiculous, but if you recorded each member of an orchestra up close and anechoicly you could in theory play all that back this way. Have a speaker in the same position, in the same hall, playing each person's contribution. Radiation patterns would differ somewhat. I believe the result would be a good fascimile to the real thing in that hall. And yes doing such a thing would be incredibly pointless.

[gmgraves]

Taste is a funny thing, heck I even love my spinach. But I won't eat no fish. My daddy always told me "if it smelled like fish, don't eat it!"

But your music is bought with your 2 cents, so

As long as you be payin the bills

You payin the cost, to be the boss.

LOL

 

That's very true. One of the reasons why classical music appreciation is declining in the United States is simply a lack of exposure. In the 1970's as our public education system started to slip from it's place as among the world's best to among the world's poorest, educators started paring everything from the curriculum that they considered non-essential. Music appreciation and, indeed, in many school systems, the entire music department was cut. This means that several generations of young Americans have grown up never having been exposed to great music at ALL. Today, if a song writer mentioned Pagliacci in a popular song, no listener would have the slightest idea what he was trying to say in his lyric, yet in the 40's and 50's a number of songs mention the character in Leoncavallo's unhappy opera as a metaphor for someone who is "laughing on the outside and crying on the inside". They could do that because the kids of those years understood the reference. They had been exposed to the music. Today's pop music audience wouldn't have a clue.

 

Another characteristic that I find interesting, is that while Western youth seem to be turning their backs on their own musical culture, youth in China, Japan, Korea, et all are embracing it. I find this odd. It's not their culture and they don't even use the same musical scale that we do (listen to some traditional Japanese, Korean, or Chinese music sometime if you don't believe me - to most Western ears it sounds like cats fighting - especially the Chinese). Yet, the Chinese love Beethoven, Brahms, Mozart, Bach, etc. and turn out more and more award winning young pianists and violinists every year. Our symphony orchestras have more and more oriental faces in them. It wouldn't surprise me to see that most American orchestras turn completely Oriental at some point. That's fine with me. After all, first class musicians make first class music!

[Sal1950]

Stereo is merely the way that one captures, in three dimensions, the space that a musical ensemble occupies while playing. This notion that one can capture the individual instruments and then arrange them in their approximate locations for proper playback is wrong-headed but more importantly, it's NOT stereophonic sound, it's multi-channel monaural sound.

 

That confuses me George. Yes a good stereo recording can add the sound of the space the performance was captured in. The air, the room sound itself with the feeling of it's space, but only downsized to the dimensions of the listening room. But also the positioning of individual performers within that soundspace is also if not the main point of stereo playback. Your talk of multi-channel monaural is only appropriate for recordings done in the most popular modern style. True minimalist recordings (such as yours) done with mainly a single stereo mic is not multi-channel monaural, but real stereo in it's most pure form.

[gmgraves]

I don't know that it is wrong headed. It is highly impractical. It is multi-channel mono. Now such a thing would be ridiculous, but if you recorded each member of an orchestra up close and anechoicly you could in theory play all that back this way. Have a speaker in the same position, in the same hall, playing each person's contribution. Radiation patterns would differ somewhat. I believe the result would be a good fascimile to the real thing in that hall. And yes doing such a thing would be incredibly pointless.

 

Not to mention wildly impractical and prohibitively expensive. I'd love to hear it once though. Of course for it to work correctly, each speaker representing each channel (and therefore, each musician) would have to placed pretty close to where that musician sat on stage. If each instrument were recorded anechoically, then the violins would coalesce into a real string section, the orchestra would interact with the hall acoustics, and the listeners would perceive the performance in real stereo! But can you imagine getting the levels in, say, a 96 piece symphony orchestra correct? What a nightmare!

 

In the 1930's, Bell Labs did just these types of experiments. They had real musicians playing in an anechoic chamber, (I don't know how many) one instrument per mike and each mike channel then feeding a corresponding loudspeaker in another room where the speakers were arranged in the exact facsimile of the musician's arrangement in the anechoic chamber. Then they started removing channels on the playback end and combining channels in the anechoic chamber. Eventually, they reduced the number of channels and speakers to two and still were able to recover the placement and phase information of the original performers, and that's where we get the idea that stereo means two-channel.

[Fitzcaraldo215]

I amuse myself every so often when in the presence of audiophiles by turning and shouting into the wall, "The sound of Bose!"

 

I almost hated to bring him up, but Bose was an MIT Professor who did some interesting research on sound and perception. That was before he became a multi-millionaire by trying to commercialize some of his ideas in his speakers, rather imperfectly say some sophisticated hi end audiophiles and I, but quite successfully in the mid-fi and mass markets.

 

In any case, I do not think there has been any credible argument overturning his early findings that to a pair of audience members' ears in the concert hall, reflected sound energy is many times greater than direct sound energy from the stage. The problem was how his speakers tried to implement that idea.

[Sal1950]

That's very true. One of the reasons why classical music appreciation is declining in the United States is simply a lack of exposure. In the 1970's as our public education system started to slip from it's place as among the world's best to among the world's poorest, educators started paring everything from the curriculum that they considered non-essential. Music appreciation and, indeed, in many school systems, the entire music department was cut. This means that several generations of young Americans have grown up never having been exposed to great music at ALL.

 

I'm sorry but I'm going to call you on that whole post. What a elitist attitude combined with a superiority complex that I find staggering.

Classical music has been declining since the days it was popular genre of it's time. Today for the majority of the people in today's world it's just BORING. It's not better or superior in any way and only your complete admitted refusal to listen to any modern styles of music can even begin to answer the question of why you have the opinions that you do.

There were great musical composers and musicians in every century and all musical styles since the dawn of music. To call everything except that which you feel is important crap is not only ridiculous but just exposes some serious flaws in the way in which you view the world and the people around you.

[gmgraves]

That confuses me George. Yes a good stereo recording can add the sound of the space the performance was captured in. The air, the room sound itself with the feeling of it's space, but only downsized to the dimensions of the listening room. But also the positioning of individual performers within that soundspace is also if not the main point of stereo playback. Your talk of multi-channel monaural is only appropriate for recordings done in the most popular modern style. True minimalist recordings (such as yours) done with mainly a single stereo mic is not multi-channel monaural, but real stereo in it's most pure form.

 

 

I agree with everything you say. What is it that confuses you? A stereo recording as opposed to a multi-miked, multi-channel monaural recording is essentially, recording the space that the musicians occupy. This space includes the instruments, the air around them, the hall in which they are performing, the phase and amplitude relationships between each musician and each instrument and the overall mixing, in the air, between the instruments and the microphones of all of these various characteristics. Whereas close miking or even contact miking captures only the single instrument itself. All other relationships (if they exist at all) are introduced, artificially, post-capture by the producers and engineers. This is actually OK in small ensemble recording where the goal might be to bring the ensemble into the listening environment (instead of vice versa). It is feasible that most living rooms could accommodate a trio or a quartet, so the idea that a performance could take place in that room is not all that far fetched. In such a case, it is not necessary for these musicians to bring their "space" with them. Your space will suffice. But a symphony orchestra? Here we are trying to bring the listener to the space where the orchestra is performing not bring the orchestra to the listener's space where it could not possibly fit, and even if it did, the acoustics would be all wrong for orchestral playback. I imagine that ideally, listening to a large orchestra via one's stereo would be the musical equivalent of watching a football game from a skybox. There you sit, all comfortable and warm in an easy chair while people bring you things to eat and drink and you watch the action through a big picture window and listen to it (and the ambience of the crowd) through a loudspeaker.

[Sal1950]

I agree with everything you say. What is it that confuses you? A stereo recording as opposed to a multi-miked, multi-channel monaural recording is essentially, recording the space that the musicians occupy. This space includes the instruments, the air around them, the hall in which they are performing, the phase and amplitude relationships between each musician and each instrument and the overall mixing, in the air, between the instruments and the microphones of all of these various characteristics. Whereas close miking or even contact miking captures only the single instrument itself. All other relationships (if they exist at all) are introduced, artificially, post-capture by the producers and engineers. This is actually OK in small ensemble recording where the goal might be to bring the ensemble into the listening environment (instead of vice versa). It is feasible that most living rooms could accommodate a trio or a quartet, so the idea that a performance could take place in that room is not all that far fetched. In such a case, it is not necessary for these musicians to bring their "space" with them. Your space will suffice. But a symphony orchestra? Here we are trying to bring the listener to the space where the orchestra is performing not bring the orchestra to the listener's space where it could not possibly fit, and even if it did, the acoustics would be all wrong for orchestral playback. I imagine that ideally, listening to a large orchestra via one's stereo would be the musical equivalent of watching a football game from a skybox. There you sit, all comfortable and warm in an easy chair while people bring you things to eat and drink and you watch the action through a big picture window and listen to it (and the ambience of the crowd) through a loudspeaker.

You should have left post 75 stand as written. Post 76 I miss understood.

[semente]

I almost hated to bring him up, but Bose was an MIT Professor who did some interesting research on sound and perception. That was before he became a multi-millionaire by trying to commercialize some of his ideas in his speakers, rather imperfectly say some sophisticated hi end audiophiles and I, but quite successfully in the mid-fi and mass markets.

 

In any case, I do not think there has been any credible argument overturning his early findings that to a pair of audience members' ears in the concert hall, reflected sound energy is many times greater than direct sound energy from the stage. The problem was how his speakers tried to implement that idea.

 

I think the problem with Bose is that he confused production with reproduction.

 

A piano playing in the Haydnsaal of the Esterházy palace in Austria will produce sound; if mic'ed adequately, the resulting recording will provide spatial cues (reflections and resonances from the hall).

If you are trying to correctly reproduce the sound of the piano and the ambience of the hall as they are registered in the recording the worst thing you can do is to use wall reflections which is what Bose's speakers did/do.

 

R

[gmgraves]

I'm sorry but I'm going to call you on that whole post. What a elitist attitude combined with a superiority complex that I find staggering.

 

What's elitist about it? All I said is that you can't expect people to make a personal decision about something if they've never been exposed to it and that our public education system used to be the organ by which young people were exposed to the arts (Yeah, I used music as the example, but after all, that's what we're talking about) and about 40 years ago, most high-schools dropped those programs. What's the difference between a program that exposes students to great music and one that exposes them to great literature? Yet literature is still taught and music appreciation largely isn't.

 

Classical music has been declining since the days it was popular genre of it's time.

 

It was never "popular" in the sense that you are using the term. It's ART, not commerce.

 

Today for the majority of the people in today's world it's just BORING.

 

I still say that's because they are unfamiliar with it.

 

It's not better or superior in any way and only your complete admitted refusal to listen to any modern styles of music can even begin to answer the question of why you have the opinions that you do.

 

You really don't get my point, do you?

 

 

There were great musical composers and musicians in every century and all musical styles since the dawn of music. To call everything except that which you feel is important crap is not only ridiculous but just exposes some serious flaws in the way in which you view the world and the people around you.

 

You don't really seem to "get it" at all beyond some knee-jerk attempt on your part to justify your own pedestrian tastes (guilt, perhaps?). Remember, you started this. I merely declined to venture an opinion on electric guitar sound because I have no personal experience with it. Then you started out commenting with mock sympathy about how pathetic I was for not embracing pop music and what a shame it was, and then you quickly descended into untutored psychoanalysis for the purpose of insult and self aggrandizement as an excuse for your own cultural shortcomings. Pretty transparent debating ploy, I'd say. And not worthy of you.

[gmgraves]

You should have left post 75 stand as written. Post 76 I miss understood.

 

 

Post 75 is my own take on why multi-miked, multi-channel recording doesn't work, while Post 76 is the practical definition of stereophonic sound.

[gmgraves]

Not to mention wildly impractical and prohibitively expensive. I'd love to hear it once though. Of course for it to work correctly, each speaker representing each channel (and therefore, each musician) would have to placed pretty close to where that musician sat on stage. If each instrument were recorded anechoically, then the violins would coalesce into a real string section, the orchestra would interact with the hall acoustics, and the listeners would perceive the performance in real stereo! But can you imagine getting the levels in, say, a 96 piece symphony orchestra correct? What a nightmare!

 

In the 1930's, Bell Labs did just these types of experiments. They had real musicians playing in an anechoic chamber, (I don't know how many) one instrument per mike and each mike channel then feeding a corresponding loudspeaker in another room where the speakers were arranged in the exact facsimile of the musician's arrangement in the anechoic chamber. Then they started removing channels on the playback end and combining channels in the anechoic chamber. Eventually, they reduced the number of channels and speakers to two and still were able to recover the placement and phase information of the original performers, and that's where we get the idea that stereo means two-channel.

 

 

I just thought of another problem with this idea. Musical instruments are more or less omnidirectional, speakers really aren't. That's going to change something, and I'll bet it changes the sound enough that it will significantly alter the experience from the audience perspective.

[semente]

Musical instruments are more or less omnidirectional, speakers really aren't.

 

I would have thought that it was the other way around.

Have a look at these examples:

 

 

 

 

R

[Sal1950]

What's elitist about it? All I said is that you can't expect people to make a personal decision about something if they've never been exposed to it and that our public education system used to be the organ by which young people were exposed to the arts (Yeah, I used music as the example, but after all, that's what we're talking about) and about 40 years ago, most high-schools dropped those programs. What's the difference between a program that exposes students to great music and one that exposes them to great literature? Yet literature is still taught and music appreciation largely isn't.

 

 

 

It was never "popular" in the sense that you are using the term. It's ART, not commerce.

 

 

 

I still say that's because they are unfamiliar with it.

 

 

 

You really don't get my point, do you?

 

 

 

 

You don't really seem to "get it" at all beyond some knee-jerk attempt on your part to justify your own pedestrian tastes (guilt, perhaps?). Remember, you started this. I merely declined to venture an opinion on electric guitar sound because I have no personal experience with it. Then you started out commenting with mock sympathy about how pathetic I was for not embracing pop music and what a shame it was, and then you quickly descended into untutored psychoanalysis for the purpose of insult and self aggrandizement as an excuse for your own cultural shortcomings. Pretty transparent debating ploy, I'd say. And not worthy of you.

 

Your words and unfounded condemnation of other peoples taste and what they consider ART has just once again put the nails in your coffin for being a elitist and having a superiority complex . We'll have to add that as the 11th commandment, "George is to be the sole arbitrator of what kind of music is and is not ART". Never mind he never listens to anything except that which his preconceived ideas tell him is ART. Maybe your right and know what is ART, but you have no idea about MUSIC

[gmgraves]

I would have thought that it was the other way around.

Have a look at these examples:

 

 

 

 

R

 

Well, not individually, of course, but taken as a whole an orchestra is more or less omnidirectional. Take away an orchestra's back wave, and it sounds diminished. That's why most orchestras play against "shells" rather than the stage scrim.

[esldude]

Not to mention wildly impractical and prohibitively expensive. I'd love to hear it once though. Of course for it to work correctly, each speaker representing each channel (and therefore, each musician) would have to placed pretty close to where that musician sat on stage. If each instrument were recorded anechoically, then the violins would coalesce into a real string section, the orchestra would interact with the hall acoustics, and the listeners would perceive the performance in real stereo! But can you imagine getting the levels in, say, a 96 piece symphony orchestra correct? What a nightmare!

 

In the 1930's, Bell Labs did just these types of experiments. They had real musicians playing in an anechoic chamber, (I don't know how many) one instrument per mike and each mike channel then feeding a corresponding loudspeaker in another room where the speakers were arranged in the exact facsimile of the musician's arrangement in the anechoic chamber. Then they started removing channels on the playback end and combining channels in the anechoic chamber. Eventually, they reduced the number of channels and speakers to two and still were able to recover the placement and phase information of the original performers, and that's where we get the idea that stereo means two-channel.

 

Articles I have read said Bell Labs (Harvey Fletcher I think) at one point did this with 64 microphones and 64 playback speakers. Their idea was wavefront reconstruction. I also have read slightly different info on the channels. What I recall, perhaps incorrectly, is they were able to keep much of the benefit as they reduced channels to 3. Couldn't get it to work to their satisfaction with just 2. Concurrently Blumlein was working on his method with coincident mics and that used of course only 2 channels. I wish more detailed info on the specifics of the Bell research were available. If anyone knows of it would be nice to point to a link if one exists.

[Fitzcaraldo215]

Articles I have read said Bell Labs (Harvey Fletcher I think) at one point did this with 64 microphones and 64 playback speakers. Their idea was wavefront reconstruction. I also have read slightly different info on the channels. What I recall, perhaps incorrectly, is they were able to keep much of the benefit as they reduced channels to 3. Couldn't get it to work to their satisfaction with just 2. Concurrently Blumlein was working on his method with coincident mics and that used of course only 2 channels. I wish more detailed info on the specifics of the Bell research were available. If anyone knows of it would be nice to point to a link if one exists.

 

I can tell you from experience with 3-channel RCA and Mercury recordings from the 50's remastered on SACD along with their "as released" mix downs to 2-channel, that the 3-channels win, hands down. That is, of course, using the discrete center channel in my Mch system for 3-channel or 2-channel playback. Try it yourself, if you can. Some of those recordings are still available. All you need is access to a decent Mch system. Even a dealer's HT system will suffice, if he has SACD playback capability.

 

If given the choice, and assuming recordings to support the format, I would rather have more surround channels, or even height channels, speculatively because the Auro 3D format is new, rather than greater numbers of front channels, however. The increased number of front channels is just a non-starter commercially. So, while you are at it, try some modern Mch recordings by Channel Classics, BIS, Pentatone, Chandos, etc. in 5-channel, with rear surrounds. I am far beyond convinced that they are today's best recordings in terms of approaching the sound of live concerts in the hall on a properly set up, high quality Mch system.

 

I do not think you will find anything useful in old pre-war Bell Labs experiments, limited as they were with antiquated recording and reproduction technology. They did not even have anything approaching mag tape at the time!

[semente]

I have never listened to a 5.1 demo; the shows I've been to only played movies in the multi-channel rooms...

 

And to be honest I never really felt attracted to it.

The expense is huge, the value for money for the same budget is probably much lower and it's already difficult to adequately position a single pair of speakers...and it takes a lot more space.

It's not really suited to European homes, less so for these tiny British living rooms.

 

Are there any integrated multi-channel amplifiers for audio?

How complex is the electronics part of the system?

 

I wonder how they setup their "rear" microphones?

In a "live" event the sound coming from the back is the rebound of what was produced in front of you and arrives (depending on venue size) with a significant delay and a fraction of the intensity or level.

 

It would be interesting to listen to a few good recordings in a properly setup multi-channel system even though I don't see myself threading that route...

 

R

[Sal1950]

I can tell you from experience with 3-channel RCA and Mercury recordings from the 50's remastered on SACD along with their "as released" mix downs to 2-channel, that the 3-channels win, hands down. That is, of course, using the discrete center channel in my Mch system for 3-channel or 2-channel playback. Try it yourself, if you can. Some of those recordings are still available. All you need is access to a decent Mch system. Even a dealer's HT system will suffice, if he has SACD playback capability.

 

If given the choice, and assuming recordings to support the format, I would rather have more surround channels, or even height channels, speculatively because the Auro 3D format is new, rather than greater numbers of front channels, however. The increased number of front channels is just a non-starter commercially. So, while you are at it, try some modern Mch recordings by Channel Classics, BIS, Pentatone, Chandos, etc. in 5-channel, with rear surrounds. I am far beyond convinced that they are today's best recordings in terms of approaching the sound of live concerts in the hall on a properly set up, high quality Mch system.

 

I do not think you will find anything useful in old pre-war Bell Labs experiments, limited as they were with antiquated recording and reproduction technology. They did not even have anything approaching mag tape at the time!

 

First a couple people seem to have lost the concept that much of the ideas esldude and I were throwing out were tongue in cheek. For sure my post on a whole front wall of soundbars was a complete bit of sarcasm and a LOL thing.

 

Second I agree with you on multi channel sound. There are some amazing sounding 5.1 recordings out there and personally I find it sad that the audiophile community for the most part have turned their noses up to the whole idea. BluRay offers just about any HD audio option you could ask for, with or without video. Sometimes I'll watch my live concerts with video. other times I leave the flatscreen off and keep the room dark. It's a win-win situation that you can enjoy any way you please.

Stubbornly insisting on 2 channel stereo only is just cheating yourselves out of a wide range of possibles.

[sandyk]

Really makes me giggle when I hear the guys speak of soundstaging with their headphones. IMHO there just isn't such a thing.

 

Then you must have a pretty crappy headphone amplifier, headphones, DAC and source material !

[Sal1950]

Then you must have a pretty crappy headphone amplifier, headphones, DAC and source material !

 

Good shot, but it ain't gonna work.

Headphones just don't do soundstageing, not in the way we talk about with speakers.

Ever heard a set of cans place a drum kit 10 feet in front of you against the front wall.

No you haven't and if you say you have I know your lying.

[sandyk]

Headphones just don't do soundstageing, not in the way we talk about with speakers.

I didn't say that they gave the same as speakers.

It is however possible to achieve a good sense of width, depth and/B] height using the right gear and suitable recordings. One example is the downmixed "The Storm" from Chesky Records. I had a compilation CD with this track as the last, and was lying on the bed listening to it with headphones.

I had forgotten about this track, and looked out the window to see the approaching storm, but it was blue sky outside.

Some Binaural recordings are also capable of similar through headphones. Chesky has at least one Binaural album available .

 

First a couple people seem to have lost the concept that much of the ideas esldude and I were throwing out were tongue in cheek. For sure my post on a whole front wall of soundbars was a complete bit of sarcasm and a LOL thing.

 

What a combination, esldude, and "esldude on steroids" ! (grin)