Because we have two ears and a bunch of processing to allow us to distinguish various sources rather than a conglomerate signal. The timing and directional cues captured by dummy head arrays is more compatible with reproduction on headphones than speakers.

"we have two ears and a bunch of processing to allow us to distinguish various sources rather than a conglomerate signal"

well said, and succient.

The short answer is that our EYES do a lot of processing and "Fill in the blanks" to what we're hearing out in the 3rd or 4th row.

The long answer is a paper I wrote back in 2004, which used to be on my website under "Articles & reviews", but seems to have slipped away somehow.....(gotta check with my web maven about that!)

Let me re-visit the original document and tweak it up a little for current-day, and I'll repost it on my Wordpress Blog, and link it here.

Ok, I just re-blogged this on my WordPress page.

Full article here:

[[url=http://[/URL]="http://westonsound…"]Recording Classical Music: Microphones and Multitracks « Joe Hannigan's Blog[/]="http://westonsound…"]Recording Classical Music: Microphones and Multitracks « Joe Hannigan's Blog[/]

Actually, when my dad was playing with the Syracuse New York Symphony Orchestra, they were making a recording at Carnegie Hall. The CBS Masterworks remote crew was brought in for this particular recording back in the early 1980s. They put out 30 Neumann microphones going to a pair of 16 track Ampex MM 1000s that they had brought in. On a break, I asked the engineer how those 3 LCR microphones sounded in the fourth row without the 27 others? He smiled and said "wait till you hear this". So he rolled the machine back and hit play. He muted everything except those left center and right microphones. It was simply gorgeous! And I asked him what the need was for those other 27? It was just something that they normally did and he told me, most of the recording would rely upon just those three in the fourth row. So they do that. Of course those other 27 would be utilized as highlights when needed in the mix. But that's essentially all those other 27 were, highlight microphones. And you can enjoy those highlights with a Highlife since they are triple hopped.

When I've made recordings at the Kennedy Center, it's a MS pair of Beyer M-130/160 with a couple of flanking M-160's and when necessary, a couple of highlight microphones on stage and/or solo vocal microphones at the front of the stage. But mostly just those two pairs hung from the ceiling at approximately the fourth row. Sometimes my flanking microphones will be Omni Neumann's KM 86/U 87's, 414's?

I make the best dummy head, me.
Mx. Remy Ann David

Remy

Impressed! You are one of the few who have made good recordings that way (and have posted about it). Do you think that the mics in the 4th row sounded better (because of the exceptional hall) than they might in a different, less good hall?

Regardless of your answer, I think you have made your point: in the right circumstances, the 'mics in the 4th row' thing works!

Joe- Just read your article- well put! Excellent points about visuals and about distancing effects. I'll keep it on file!

Exsultavit, post: 388038 wrote: Do you think that the mics in the 4th row sounded better (because of the exceptional hall) than they might in a different, less good hall?

4th row back in some halls would be about the right distance for condenser stereo pairs if the conductor is right at the very edge of the stage. Most halls will not ever be as good as Carnegie's main hall. Lincoln Center for instance is an abomination by comparison.

Placement of a main stereo pair is dependent primarily on three things:
#1 the type of microphones one is using,
#2 how large is the ensemble and how close to the lip of the stage or proscenium are they set up, and
#3 how good is the hall acoustic.

We try to minimize visual interference automatically but when push comes to shove, an audio engineer is after good audio.

So...are we talking about an array, a stereo pair or, as the title says, "a mic"? Though the OP mentions dummy head setups the post seemed to be about putting one mic where people sit. Adding a second mic completely changes the game.

I usually use an omni pair, but I was keeping it open. More a discussion of why we, as audience members, hear things so differently than microphones.

I get requests (usually from folks who don't record, but sit in the audience) on why I put mics close. I was trying to think of a quick, simple way to answer them.

Of course, sometimes it DOES work to put mics in the audience area. As John pointed out, it depends on several things. And I just noticed that I unwittingly referred to putting a pair of mics "the fourth row center at Carnegie Hall". I was just making up an example, but Remy pointed out that she actually DID that (or observed it) in that hall, and it worked quite well!

Okay.

One problem with putting them in the audience is that they're closer to the audience noise than the intended source (assuming it's a live recording with an audience) so inverse-square law is working against you.

When placing mics in the audience, crowd noise is an issue. Height is your friend here as well as judicious compression of the applause. A short vocal mic stand won't be useful at all. Around here I have to use the front two rows of center seats frequently.

Sent from my DROIDX using Tapatalk 2

bouldersound, post: 388071 wrote: Okay.

One problem with putting them in the audience is that they're closer to the audience noise than the intended source (assuming it's a live recording with an audience) so inverse-square law is working against you.

Certainly true for live recording, but even for empty house recordings virtually nobody records this way. If I read correctly, the 4th row example placed the mics up in the air - still not where the ticket-holders sit.

One of the problems with on-the floor recording is that much of the sound produced would have a stagefull of stuff to get thru before reaching the mics - much of the direct sound and highs are lost. It's probably no coincidence that mics praised for the most convincing recordings always seem to have a treble response bump . . .

We require a different mix of information (direct sound, high freq information, etc) on record than in real life, due to the inherent shortcomings of playback thru 2 (or 5+) channels. Playback presents the ears/brain sonic information in a very different way than real life. During playback, sonic events are both delivered and received in an unnatural way.

For perception of a 'real' sound located 17 deg left of center (say, a percussionist striking a wood block) requires only one sound source. To simulate this in playback requires at least two sources. We have intuitively developed recording practice (and gear) that helps to compensate for the fuzziness that any image located between speakers will have.

It's interestng to note that in the whole recording process, the one piece of gear that we don't often prize for neutral response is microphones. When we do use a neutral microphone, it is either 1) being used to make a binaural (headphones-only) recording, which removes many problems of playback, 2) Is positioned somewhere we would never put our ears in a concert hall, or 3) is being used for measurement, not recording.

In the natural world, sound from one source is received and comparitively processed via two ears. Accurate placement can occur from an infinite number of listening positions. In playback, it's almost the opposite:

Real world: One source per sound --> from nearly any listening position --> accurate perception
Playback: Multiple sources per sound --> only one ideal listening position --> virtual perception, never fully real, extremely dependent on speaker-room-listener variables.

[[url=http://[/URL]="http://en.wikipedia…"]Wavefield Synthesis [/]="http://en.wikipedia…"]Wavefield Synthesis [/](requires a pretty large number of individual speakers) is around the corner, but it will be a while before it's practical. If this playback ever becomes the standard, the way we make recordings could be much different.

-- Mark