Quote from: al w. on Today at 08:55:24 AMin addition to the excellent advice above... re: crowd noise -- don't be afraid to run wide AB with your cards. I've had massive improvements with crowd noise running my hypers AB spaced 30cm
sure there are tradeoffs with regard to stereo image and such, but it's worth it to me
just my two cents!
^ +T
Yeah, except now we're getting into sophisticated management of crow noise in the "rank newbie" thread. Wider microphone spacing doesn't reduce the level of the noise, but helps portray in a way that begins to separate some of it from the music, making it less distracting and annoying even though its no quieter on the recording. Do the other things if possible (get closer and/or higher) as they are more fundamental in increasing the ratio of music to noise, but using a stereo microphone configuration that has a wider spacing can help perceptually.
It does so by causing the randomly distributed chatter to be more spread out across the playback image, with more of it pushed out toward the sides of the playback image, leaving more room for the music in the middle, which helps your ear/brain more easily separate those things.
Because omnis tend to be spaced more widely, the phenomena is especially noticeable when using them. Couple reasons for that. One is that a little bit of the proverbial "hole in the middle problem" with wide-spaced-omni actually becomes advantageous. "Hole in the middle" is a bit of a misnomer. It's more like a "thinning out" of image placement to either side of center. Specific sources tend to image either near the center or farther over to one side or the other, and somewhat less so between those three positions. The way in which it helps with portrayal of audience noise is that the music remains centered since the microphone pair is oriented perpendicular to the stage and PA. Because the path-length from those sources to both microphones is the same, that content is fully "in phase" across both channels. In contrast to that, randomly distributed audience noise sources will be picked up with varying phase offsets, causing them to be more widely distributed across the playback image, and due to the wide spacing, a lot of that will have a significant phase offset between channels causing it to image well off to the sides. The diffuse reverberant content (that is the non-specific, non-discrete audience noise that's not phase-correlated at all) doesn't image discretely or follow the hole in the middle thing but is portrayed diffusely and evenly across the entire playback stage, sort of gluing it all together.
Some more advanced arrays place a third microphone, stereo pair or whatever in the center between the two omnis, taking further advantage of the "hole in the middle" phenomena, and allowing the omnis to be spaced a bit wider still.
Is noticeable with omnis spaced 3', which is generally safe for two channels. Its really noticeable at about twice that spacing, but you then need to be careful about the situation unless running additional mics in the center. Times when I've been recording from an audience position but not able to hoist high, using an array that includes omnis spaced about 5' along with other mics in the center, I've been amazed how now very close audience (which is still gonna be loud regardless simply due to proximity) are mostly heard only over in one channel or the other, unless they are positioned pretty much directly in front or behind.
Apologies to OP John for going a bit overly far into the weeds on this. I'd advise you not to worry about this stuff for now! Keep your focus on the big picture, begin making recordings, and refine technique over time. Just know we're here to discuss this kind of arcane stuff as you move forward.