near field VS room interaction...the way it is supposed to be done

[JinMTVT]

Just a quick thought i had recently ...reading posts and webpages

would like to have your opinions on this matter , so i can understand etc..

When a regular recording is done ( they use stereo omni micros? )
the sound that is recorded is what one would've hear where the micros are located right ?

why in the hell, do we then want our own room and contraption to modify or reverb this recorded information since it already contains spatial and temporal information while it was recorded ?

aren't we adding things that aren't supposed to be ?

why aren't headphones the "perfect" way to listen to music then ?
i've tried several binaural recordings, and some give pretty amazing results
but it lacks the "feel" or volume loudspeaker listening session
( or the headphone disposition on my head/ears just make it wrong )

i am under the assumption, then when playing back a recorded live event
( not too sure on how studio recorded things work in all that )
that was done with a single stereo mic ( aka orchestral ? ), the best way to listen to it would be direct loudspeaker sound with no additional modifications/reverbs and indirect reflections etc .. ?? ( near field )

please enlighten my path ... trying to understand what is the real goal here

( that brings questions on a few loudspeaker designs ...like omni directionals
etc.. )

also, please tell me how studio recorded music is intended to be played back ?

 

[dantheman]

Regular recordings don't have a regular. The need is standardization(s)and there's not much of it about.

Until then, the 'flat' thread is probably a decent guide. A lot of malarky in there, but it sounds like you can sift through it.

Dan

 

[cuibono]

You've brought up a complicated topic, with a lot of facets.

First off, omni mic's are not used as much as cardioid or bi-directional (ribbon) mics. In fact, they are used much less often. The first thing to understand is that the brain does tons of processing on the sound it picks up at the ears. Tons. That is why, even with just a stereo pair of microphones, a recording doesn't come out sounding 'natural' - your brain is missing a bunch of information and cues that it would otherwise have in the 'live' situation. I bet there are almost no recordings done with just two mics. The absolute minimum seems to be four, and that is for very serious purists.

Basically, recording is an art, where there are tricks and lots of processing done to get the recording just to sound 'natural', say nothing of what it takes to be a 'commercial' product. It is a testament to the complexity of our sensory process. Binaural recordings are very interesting, but they too lack certain cues - particuarly, they can't trick the brain into believing the sound is originating outside the head.

About playback, there is no general answer. For instance, classical music is not made for radio play, and usually sounds really bad over a standard, crappy radio. Most pop music is made for radio play, and sounds really bad in a really nice stereo setup.

Personally, I wouldn't worry about things too much, and just do whatever you enjoy.

 

[JinMTVT]

"Personally, I wouldn't worry about things too much, and just do whatever you enjoy."
unfortunately not something that i accept

i will research a bit on cardioid and bi-direct mics to undestand, thanks to pointing that out


but i still wonder, if one is to record sound wave pressure
( because this is only what there is to it nah ? )
at a fixed point with a certain type of mic
this recording is supposed to hold all of the information
( again only soundwaves ) that this location sees during the recording
( assuming near perfect mic )

so then, knowing how the mic is recording, shoudln't we be able to then playback this recording with appropriate driver
but then, we can't place our ears at the exact same place as the new driver
so this is where it gets a bit mixed up for me

i seriously thought that near field listening , minimizing room interactions and other shiznits, would emulate the recording pretty well to our brain ??

if the drivers play the sound pressure wave accuratly, just as our ear woul've received if at the same location/time than the mic, and if new room and setup doesn't transform anything or add anything significantly, wouldn't we be getting the exact same pressure wave ?

 

[dantheman]

Believe you me, most recordings are radically manipulated post microphone--thankfully. There are actually good reasons for that--pleasurable listening is a goal. This is part of the reason why the unflat playback notion is off.

The goal of the home audio should be a reasonable facsimile of the mastering engineer's intent. Forget about the mic technique.
Read this as it should help and the attached links at the bottom:
audio blog: Tightening The Loudspeaker, Recording and Room Connection

Dan

 

[dewardh]

the sound that is recorded is what one would've hear where the micros are located right ?

Have you ever been at a recording session, either orchestra or "studio", and seen where "the micros are located" ? ? ? For the most part you wouldn't want to be there even if you could.

It is mostly possible, with much fussing and adjustment from the mixer to the loudspeakers themselves to get the overall tonal balances acceptably correct, but there is enough variation in production technique (and intent) that even there you will find no one "solution" that sounds right with all recordings.

Spatial cues are a whole other ball of wax . . . there is in actual fact no way to accurately encode the "spatial and temporal information" that you would hear in any normal listening position in a way such that it will be correctly reproduced by two loudspeakers in a room. The best that we can accomplish is a collection of aural "clues" that trick the mind into creating a (mostly) satisfactory illusion . . . and in doing that it turns out that reflections from the final listening environment can be, in some cases at least and probably in most, more of a help than a hinderance. Anechoic listening is no more satisfactory than it is practical . . .

One thing that almost everyone (who has worked in the field) agrees on, though, is that no matter what your "theory" and how much you think about it at the end of the day reality still trumps all our grand designs . . .

 

[dewardh]

The goal of the home audio should be a reasonable facsimile of the mastering engineer's intent.

Any "mastering engineer" with that kind of an ego problem should be taken out and shot.

The goal of "live" recording should be to produce a reasonable facsimile of the original performance, and of a "studio" recording to produce a product that satisfies the artist's and producer's intent. In both cases there is, and will continue to be, argument about the extent to which the recording should be "tailored" to the typical consumer's reproduction environment (that being, ultimately, the producer's call). Live "classical" recordings are most commonly presumed to be intended for (relatively) high quality playback equipment . . . and there *is* an "original performance" that serves as a reference. Studio recordings have no "original performance" as reference, and are typically produced to "sounds good to the typical consumer" standards. For the most part these days that means lower "quality" than most "high end" listeners would want, or expect.

 

[Rudolf]

JinMTVT,

you probably will be interested in these microfone demonstrations. They will show you, how even "just two mics" can lead to wildly different recording results.

Rudolf

 

[purplepeople]

About headphones vs loudspeaker. Your whole body will feel the loudspeaker playing. It may not be something you notice, but the vibrations are there.

ensen

 

[speaker dave]

if the drivers play the sound pressure wave accuratly, just as our ear woul've received if at the same location/time than the mic, and if new room and setup doesn't transform anything or add anything significantly, wouldn't we be getting the exact same pressure wave ?

The problem is that the wavefronts that create those sound pressures at the microphones are coming from all different directions. A pair of omni mics wouldn't care about arrival direction but human hearing (directional ears and time/phase difference sensing between the ears) will perceive the arrival differences.

Listening with headphones or with 2 speakers in a dead space gets you a pretty good binaural experience, except you can't subconsciously turn your head to figure out whats ahead and whats behind, so it isn't a perfect solution. The soundfield will typically collapse inside your head.

With conventional speakers you would need a good number of surrounding systems to fairly replicate a space. Alternativly you can mess with the room and speaker's directivity to try and simulate something near to the soundfield of a real performance space with only 2 channels, but that is made difficult because the dimensions are fairly disimilar.

Gee, I guess if it was easy we would have perfected it years ago.

David S.

 

[graaf]

When a regular recording is done ( they use stereo omni micros? )
the sound that is recorded is what one would've hear where the micros are located right ?

wrong, it doesn't work that way, in fact no one knows how stereo works exactly

in case of binaural - which is not stereo - perhaps it is more like the sound that is recorded is what one would've hear
this is at least the intention BUT - and it's a really big but - still we don't know how to reproduce it because still not all information required for natural sounding sound event is in the recording - most of head RTF is not perfectly natural and pinnae RTF are absent

why in the hell, do we then want our own room and contraption to modify or reverb this recorded information since it already contains spatial and temporal information while it was recorded ?

(...)

why aren't headphones the "perfect" way to listen to music then ?
i've tried several binaural recordings, and some give pretty amazing results
but it lacks the "feel" or volume loudspeaker listening session
( or the headphone disposition on my head/ears just make it wrong )

I think that there is in fact ONE answer both those questions - our hearing mechanism expects in natural sound events sequences of cohehent reflections that make sense - also from perspective of head and pinnae RTF

Moulton is right:

I'd like to redefine what we mean by a sound. The conventional definition is that sound is something that emits from a musical instrument. Psychologically speaking, that's not quite true. It's the energy emitting from a musical instrument plus its volley of early reflections that actually goes into our perception of what a sound really is.
(...)
In actual fact, loudspeakers themselves are perceived in stereo as early reflections of a sound whose direct version we missed. So we're listening to the first of a set of early reflections that includes all of the walls and so on

I would say - loudspeakers themselves SHOULD BE perceived in stereo as early reflections of a sound whose direct version we missed because more often they ARE NOT because reflection pattern resulting from loudspeaker-room interaction doesn't make any sense...

...and loudspeakers work somehow thanks only to a kind of trick that fails as soon as listener moves out of the narrow sweet spot or sometimes even when we listener just moves his head

therefore to get natural sounding soundstage some omni, dipoles or other reflecting designs/ placement tricks are required

regards,
graaf

 

[graaf]

The problem is that the wavefronts that create those sound pressures at the microphones are coming from all different directions. A pair of omni mics wouldn't care about arrival direction but human hearing (directional ears and time/phase difference sensing between the ears) will perceive the arrival differences.

yes, absolutely

Listening with headphones or with 2 speakers in a dead space gets you a pretty good binaural experience, except you can't subconsciously turn your head to figure out whats ahead and whats behind, so it isn't a perfect solution. The soundfield will typically collapse inside your head.

well, You can always put yor head in the vise ;-)

Gee, I guess if it was easy we would have perfected it years ago.

I think You greatly underestimate two factors - power of mimetic inertia and power of Kuhnian paradigm

actually - the more inside we are the more we do what other insiders do and the more educated we are (in our paradigm) the less we can see solutions that can be found outside

regards,
graaf

 

[JinMTVT]

wow so many interesting replies thank you all for your great help

i will try and read more about recording and mics in the next few days before
typing more stupid ( read ignorant ) stuff on here ahah

i still don't understand why we aren't doing it better than what we have here, now
i've just been to Montreal salon son et image festival,
and again, ( something like my 6th-7th time ) was not impressed much at all
even by some 150K$+ HT setup
( in fact the 8K$ HT setup using TOTEM loudspeakers was far more impressive )

i have never been in an anechoic listening environment...
how does it sound?
why is listening only to recorded sound without any room interactions
( just like with headphones? ) less impressive than in a regular room ?

i also understand that studio recorded music is only what it is

what about orchestral music? is it recorded with multiple scene mics ?
or with a single stereo mic?

i will try to listen to the orchestral music that i have in my library , and try to discern mic setup and soundstage

and true as it was pointed out, loud sound vibes all of our body and adds on something HP cannot reach , even when the quality using loudspeaker is lower than that with the HP ( from my experience ) there is some additional feeling

 

[dantheman]

Any "mastering engineer" with that kind of an ego problem should be taken out and shot.

The goal of "live" recording should be to produce a reasonable facsimile of the original performance, and of a "studio" recording to produce a product that satisfies the artist's and producer's intent. In both cases there is, and will continue to be, argument about the extent to which the recording should be "tailored" to the typical consumer's reproduction environment (that being, ultimately, the producer's call). Live "classical" recordings are most commonly presumed to be intended for (relatively) high quality playback equipment . . . and there *is* an "original performance" that serves as a reference. Studio recordings have no "original performance" as reference, and are typically produced to "sounds good to the typical consumer" standards. For the most part these days that means lower "quality" than most "high end" listeners would want, or expect.

That implies nothing about the mastering engineer's ego. Oye Deward. There are actually good people in this our world. Believe it or not. Obviously we don't shoot all the bad ones anyway.

Dan

 

[graaf]

i have never been in an anechoic listening environment...
how does it sound?

very bad, a disaster, sound in the head, here is an account of a particularly impressive example of such disaster:

"Interestingly, a demonstration of four-loudspeaker Ambisonic recordings played in an anechoic chamber yielded an auditory impression that was almost totally within the head. This was a great disappointment to the gathered enthusiasts, all of whom anticipated an approximation of perfection. It suggested that, psychoacoustically, something fundamentally important was not being captured or communicated to the ears.
An identical setup in a normally refl ective room sounded far more realistic, even though the room refl ections were a substantial corruption of the encoded sounds arriving at the ears

http://www.diyaudio.com/forums/multi-way/172806-flat-not-correct-stereo-system-91.html#post2507802

http://books.google.com/books?id=sG...dspeaker Ambisonic recordings played"&f=false

note that Dr Toole is also quoting Moulton

why is listening only to recorded sound without any room interactions
( just like with headphones? ) less impressive than in a regular room ?

we don't know, although I have my hypothesis that I have already presented in my previous post

regards,
graaf