Topic: Recording Interference

[jamroom]

At a recent show, I recorded six sets from the various artists involved. Due to the venue limitations. I wore the mics attached to my collar. On three of the sets there is varying degrees of interference. First set, it lasts for 30 seconds and is a constant stream of bursts of noise. I took a couple of screenshots of this in audition in waveform display. The later sets only have much shorter bursts. Two questions.

1) I'd like to try to clean this up as much as possible using audition (2.0). Any help would be appreciated. I have tried a few things, but to no avail. Not expecting miracles and I already have had to say to folks that there was a problem with the recording and that's a bit depressing.
2) I don't think this is standard mobile (cell) phone interference, as it doesn't follow the usual pattern you hear over speakers when the phone is too close. Any ideas what it might be?

Here is a sendspace link to a very short snippet (in mp3 - 242kb) of the noise with the acoustic guitar prelude. Be careful which "download" you click. Click on "Click here to start download from sendspace", or you will end up trying to download an app.
http://www.sendspace.com/file/gcbw0l

You can see the underlying music quite clearly

This screenshot is a zoom-in of the above noise.

[LikeASong]

In my opinion that is unrecoverable. Strange noise you got there, mate...

[yousef]

I don't know what the hell that is but I would say that it is completely unrecoverable. I think the waveform itself tells you as much. Sorry - I know how much this sort of thing stings.

There is something oddly familiar about the character of the noise - brings back memories of the badly burned CDRs.

What recorder and media were you using?

[bombdiggity]

Ouch. 

Oddly I did have a bit of a cell phone buzz on something for the first time a few months ago.  Fortunately just a few brief bursts and not hugely loud.  It happened when a friend (sitting next to me) was operating the gear.  I attribute it either to some peculiarity of his cell (or the very large venue).  Don't think I've ever had it happen before but it is disconcerting.  And weird since I can't quite tell how something like that would enter the recording chain. 

[jamroom]

I have given up on the long burst, but was hoping there was a good way of reducing the noise on the short bursts so that it doesn't seem so obvious over the volume level of the unaffected parts of the track. I have been having trouble with this. It still sounds loud.

Gear was CA11v2->9100->R05.

Typical that out of six sets, two of the three affected were the two I most wanted. Heh. Life can be cruel. I guess that interference will always be with us, given how prevalent the constant use of the phone is at gigs.

[yousef]

Can you send me a link to a full song and I'll have a tinker? I imagine that there is very little music under those bursts of noise but I think there's certainly scope for reducing the discrepancy between the music peaking at -28dB and  the 0dB interference...

[LikeASong]

I think you'd better fade out the music before the interference starts, fade in when it ends, and do some crossfade in order make it the most comfortable to the ear.
Good luck if you even have an attempt to remove/reduce the interference!

[jamroom]

Should anyone be interested, I don't know what the source of the interference was, but the cure was replacing the sd card. Go figure.

[Gutbucket]

You could try spectral editing, which would probably be the best bet for removing the short bursts of periodic noise.  It would not work on a 30 second long solid burst however.  I'm not aware of any freeware that features that, but you can load a trial of Izotope RX or Samplitude, Sony makes one, I'm sure there are others.  Basically you look at a visual display and draw a box around the offending sound and the software then reconstructs that region by looking at the audio surrounding it, based on some parameters you specify.  For best results, read the documentation to understand which parameters are appropriate.  You would need to draw boxes around each individual burst, but it might supprise you at what it can do.

[trustthex]

I had an SD card issue w/ my LS10 last spring, never had one w/ my R-09.  Wish I marked down which card that was.

[F.O.Bean]

i CANNOT STRESS ENOUGH you reformat your cards EVERY SHOW, or until it is FULL. NEVERRRRRRRRRRRRRRRRRRR just delete stuff off the card. you MUST ALWAYS reformat once your music is safe and where it needs to be

[John Willett]

I had an SD card issue w/ my LS10 last spring, never had one w/ my R-09.  Wish I marked down which card that was.

I only use SanDisk cards - the best and most reliable.

[John Willett]

i CANNOT STRESS ENOUGH you reformat your cards EVERY SHOW, or until it is FULL. NEVERRRRRRRRRRRRRRRRRRR just delete stuff off the card. you MUST ALWAYS reformat once your music is safe and where it needs to be

I absolutely agree,

[microburst]

I reformat my card and deck after each and every show (as long as I don't forget  , which is very rare).  Want to hear some annoying radio interference?  Listen to this...http://archive.org/details/kdtu2013-01-11.mk5.flac16.  That's some annoying hum right there.

My friend Tony said his recording of this set and all the other sets from this room and this particular day are wasted...said 1-2 minutes are fine then there's a horrible screaching/glitching noise followed by essentially no music for each and every set.  He was running into a Littlebox so take it for what it is.  Anyway, seems my sonosax picked up some interference but not horrible but fortunately the V3 didn't pick it up for my other pair - clearly some better shielding going on in that unit vs the sax.

[jamroom]

i CANNOT STRESS ENOUGH you reformat your cards EVERY SHOW, or until it is FULL. NEVERRRRRRRRRRRRRRRRRRR just delete stuff off the card. you MUST ALWAYS reformat once your music is safe and where it needs to be

Care to explain why? The card in my recorder (no, not the crap one) has been in constant use for five years now with nil problems. I have only ever deleted the files after backing them up. The offending card in my OP had been formatted, but not used for recording before.