An Audio Test

[filkertom]

The second half of my DucKon set was recorded in a meeting room, as opposed to the ballroom. There's a low consistent hum in the background, more obvious when I'm not singing, and I can't seem to remove it without sucking all the life out of the overall audio. A song from that second half is right here (a 60 MB download of a .WAV file, "Smurfin' Safari" in case you're interested). Would some of you mind listening to it and giving me your opinion as to whether it's too distracting, or not noticeable, or what? And if you have an idea as to what I can do to get rid of it, that'd help as well. I've been EQing for a lot of the day, to no good effect.

ETA: I think I got it, or got most of it. A noise gate, a wedged notched EQ starting at 113 Hz, and another EQ to add warmth back in the middle. The hum is still there, but much less obvious than it was.

Comments

[solarbird]

Still downloading, but after listening to the first 20 seconds of it or so: I think you need a super, crazy tight notch filter around 225hz. (That's not an exact figure; the dominant tone in the hum is just sharp of A220. Make it about 4hz wide and search until you get the worst of it.)

eta: listening to it all the way through, you're right, it does get submerged in other noise. You might also try a noise gate approach, particularly if you have a frequency-range-specific noise gate.

[solarbird]

Damn, it's over a way wider set of frequencies than I'd hoped. That sucks. So much for the notch hope.

The best I can think of right now is to filter around the worst of it where it's at its loudest - it cuts out during the guitar intro, in this case, at least - and live with the resulting lack of lower midrange until you can crossfade over to the full recording (well, with the low end rounded off to get rid of some residual rumble) at best opportunity. Like, for example, here:

http://solarbird.net/Temp/smith-2010-07-06-01.wav

(I figured a public URL was okay given you'd posted one. Tell me when to yank it and I'll do so instantly, of course.)

You'll note there's still some hum in this. I got rid of as much as I could without making that section sound like ass, so, tradeoffs.

[scifantasy.livejournal.com]

I...am not sure I even hear it. So, one vote for "not noticeable."

[vik_thor]

A second vote for "not noticeable".

[tollermom]

If I'm listening for it, I hear it during the intro, but it's not annoying and I don't notice it once you start to play. I didn't put it on the big speakers... that's just with headphones or the laptop speakers. For a live recording, it sounds pretty damn good... I don't know that I'd risk sucking the life out of the recording by trying to notch it out.

[dave-ifversen.livejournal.com]

It was only noticeable on the quiet parts. I played around with some noise reduction during the intro http://www.ifversen.org/00testwav1_intro_NR_short.wav See if that sounds any better...

[dave-ifversen.livejournal.com]

I used an FFT noise reduction algorithm in the sound editing software I have. Of course, that file is only the first minute or so, just the spoken intro leading into the guitar part. That file will be deleted the instant you say so..

[johnridley.livejournal.com]

I was going to suggest trying FFT.

[ruisseau.livejournal.com]

I hear the hum during the spoken intro (sounds like an air conditioner), but once you start playing, I don't hear it anymore.

On a secondary note, I wish I hadn't been napping while you were doing your second concert, dammit!

[hms42]

I don't hear the problem, but I can run that thru Audition with a noise filter on the dead air to see if I can pull it and not screw up the recording. Also, did you get the link I sent to you last week?

[bedlamhouse]

I'd try gating it first, even a simple gate just based on volume level. If nothing else, you might be able to manually go through the track and turn the gate on and off in the specific places where nothing else is there (I know I can do this with Cubase).

[shockwave77598.livejournal.com]

When your voice picks up and the AGC kicks in, the flourescent hum goes away. Before that, yeah, it's pretty noticeable.

You use Reaper, right? There's a spectral filter that lets you draw a rectangle around the spectra you want to delete. Or any notch filter at 60hz will work as well. Double check with a spectrum analyzer first because lots of flourescent bulbs also radiate at 120hz as well.