> I have a recording from a lecture. It was recorded in a large > auditorium and of course it show in the recording. I'd like to process > the recording to get a more intimate sound. It there any way of > reducing that ballroom echo a bit? If it can be done with a ladspa > plugin so much the better. Hi, Alex, You can try various filtering things, but all are subject to a certain amount of failure. I don't know about plugin modules, but I can tell you in general, the way you'd fix this is using "Deconvolution." The idea is simple -- it's basically "unfiltering," but there are a couple of problems. 1: You have to have some idea what the room does to the signal. (Possibly some info can be taken from your recording.) 2: It's really sensitive to the numbers you get from the first step -- so even in theory (i.e., on paper) it doesn't work all that well. In practice it's pretty hard to make work -- this is really "black magic" DSP. [though there's no such thing.] So, having said all that, you will probably get *better* results by using noise gates with a fairly high "off" level, i.e., not hard-gating, and possibly by using a key input that is bandpass filtered at about 2500-3000 Hz (tune by ear to the speaker's voice -- and filter out lows and highs.) I'm pretty sure the last will be possible using LADSPA tools -- though I can't say exactly which you're looking for! If it's any help in the future, I've found that most speakers (if this were at University, not public speaking for $$) will let you park your recorder closer to the stage -- the best answer of all is to keep the reverb out of the recording to begin with. It'll never sound like a voice over recorded in a studio, but maybe something here is helpful. Cheers, Phil Mendelsohn -- Dept. of Mathematics, 342 Machray Hall U. of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 Office: 446 Machray Hall, 204-474-6470 http://www.rephil.org/ phil at rephil dot org
