Question on recorded feedback

HappyPuppy1033 · #1 01-23-2009, 02:14 PM

My band has a live recording and I'm doing some amateur mastering on it. In a couple parts we got some microphone feedback, does anyone know what frequency mic feedback occurs at so I can try and tone it down? If I can't entirely eliminate it, I'd at least like to try to make it so it doesn't hurt your ears if turned up loud.

MakiSupaStar · #2 01-23-2009, 02:18 PM

As far as I know, if you're getting feedback, you're not going to be able eliminate it without eliminating the other parts of your recording. All you can do is punch down the volume at that point to compensate for it.

heavyfunkmachin · #3 01-23-2009, 02:40 PM

mic feedback has to do with room acoustics, size of walls, sounds on the room... etc...

i´m NO expert, but i believe that usually mic feedback has a very narrow frequency band...

what would I do if i were in your position?

i would copy and paste the fragment were you have feedback in a new track, check among feedbacks during the recording to make sure that they all have the same pitch, play the bit in a loop and figure out the pitch of the feedback... with a piano, software (band-in-a-box, reason... you name it), by ear... im sure you can find online some kind of piano... i dunno... but once i had find the exact note at witch it´s feedbacking, i´ll have the frequency of the feedback (maybe this can help)

then, I´ll get the software´s eq and dump the feedback´s frequency when it happend.
you might loss some sound information, but that´s the easiest way i can think right know. maybe there´s a better way to do it... some hitech software or something... but that´s just what i would do.

good luck!

Ben Clarke · #4 01-23-2009, 02:41 PM

Zoom in on the waveform so you can select just the areas with feedback. Try a narrow, deep EQ cut. It will likely be most effective between 800Hz and 5KHz. It really varies. If this is too fiddly for you, you can also just crush that section (if it is brief) with a comp or limiter to mitigate the nastiness.

It always takes some experimentation to get good results with this, but stick to it and you will be able to get it listenable if nothing else.

hbarcat · #5 01-23-2009, 04:50 PM

It wouldn't be rock and roll without feedback.

agreatheight · #6 01-23-2009, 04:59 PM

Take the track and run it through a simple spectrum analyzer. You may be able see a spike where the feedback is and be able to get an estimate it's frequency. Then set up an eq with a tight q or band and move it around until the sound is attenuated.

You could also try a more advanced spectrum analyzer, like the one in Adobe's Soundbooth. It allows you to remove sounds visually. I have used it to remove birds chirping in video interviews. They do a 30 day trial.

If you get stuck, email me and I might have time to peek at it.

heavyfunkmachin · #7 01-31-2009, 02:00 AM

+ 1

much smarter than my answer!