Back/Surround Ambience (recording)

[kfbkfb]

Much has been written about how instruments/vocals are placed in the mix in the front channels of a surround sound recording.

AFAIK, recording ambience isn't well defined, I don't know if there are "sweet spots" for microphones for capturing the ambience in such a way as to be able to identify the recording hall/venue.

Are only 2 mics used (1 for LB/LS, 1 for RB/RS) or are several mics placed at various heights and distances and mixed later to try to accurately capture the ambience?


Kirk Bayne

 

[proufo]

Ambiophonics -- Recording Engineers' Corner

 

[jimfisheye]

There are physics based stereo techniques to capture a field recording in natural perspective. XY, ORTF, 3-1 spaced pair, Decca tree, and a couple others. Rooms can be complex. If you have some church like place where you hear distinct echoes from different alcoves and such. You'd have to mic that up if you wanted those elements captured to reproduce in discrete surround.

Usually the room ambience isn't treated with that kind of attention to detail. (Kind of busy right now making the music elements on point!) You want the overall sound of the room and/or the sound of the audience.

Sometimes there's a pair of mics at the sound board. Because it's convenient to place them there next to where they plug in and in your little FOH safe zone. That gets the sound of the band in the room at that spot, for good or bad. I like to put a pair of mics on the edges of the stage pointing out at the audience if I'm putting up extra mics. Keeps them in sync with the rest of the recording right out of the box for one thing. (Not that that's a problem after the fact.) Gets the excited front row audience more than the boring middle of the room audience. I often don't put up room mics though. If someone asks, I'll sarcastically quip that I have plenty of "room mics" on the stage! (I guess that isn't very surround minded though, is it? Maybe lose a point there.)