Re: [linux-audio-user] Live recording : Post production/ removing noise

When I was a student at Oberlin I worked for the audio department of the Conservatory, so I recorded somewhere around 100-150 classical recitals a year, almost all with a stereo pair. I used a whole lot of small diaphragm condensers in an ORTF setup (cardioid mics with 110 degrees between and the capsules 17cm apart). I'm a big fan of the Neumann KM184 mics. I also used the Sennheiser MKH140 mics sometimes, and shoeps CMC cardioids. I didn't worry too much about the music getting mixed down to mono, which is why I didn't use an XY configuration very much. Generally I prefer near-coincident (the mic capsules a little apart, as in ORTF) to coincident(The capsules right on top of one another, as in an XY setup) because it captures delay as well as amplitude information and gives a stereo field that I like better. I less commonly used a spaced pair of omni mics, which in my understanding capture the stereo field mostly with delay info. (Sources on the left hit the microphone on the left a little before they hit the right mic) I like a spaced pair for a large ensemble, and for a really big group sometimes I'd use 3 mics evenly spaced, or even an ORTF flanked by omnis. We had a couple pairs of Neumann M150 mics which are absolutely wonderful. You do need to pay attention to where you point them though, because they get more directional at high frequencies. I also used Sennheiser MKH20 mics for less critical applications. With all of these stereo pair techniques, I pan the left mic hard left and the right mic hard right, or more commonly, I'm just recording each mic directly to the left and right channels of a DAT with a CD backup. Also, it's important to be flexible, probably 85% of the time I basically just set up a pair of mics in the center of the room about 10-15 feet in front of the performer (for an individual or small ensemble. Back it up a bit for larger groups) with one of the techniques described above. It wasn't unheard of though, to vary wildly from the standard 2-mics-in-the-middle approach, so if you have time for a sound check, it's nice to be able to move the mics around and let your ears decide. Depending on your clientelle that can be a rare luxury, though, so get used to figuring out why a room sounds the way it does so you know where to put your mics. As far as fixing noisy recordings, there's only so much turd-polishing you can do, but I've had some success with the Gnome Wave Cleaner. You've got to be pretty careful though, because if you use it too aggressively it makes things sound really nasty. Watch out for a kind of metallic comb-filtery kind of effect. hope this helps, spencer On 8/25/06, ish(a)sarai.net <ish(a)sarai.net> wrote: