How to track the source of high-pitched audio interference?
April 11, 2012 7:30 AM Subscribe
I have high-pitched ringing in my the recording set-up of my new home voice recording studio (it seems to have a pulse, not steady, and occaionally disappears). Where should I start trying to get rid of it?
posted by acm to Technology (21 answers total) 1 user marked this as a favorite
I'm using a brand new Mac Powerbook (OSX Lion), Mbox 3 mini (runs to computer via USB A/B), balanced XLR cable. Have checked mic and cables at a nearby studio and they seemed fine. Ringing resistant to the following:
1) unplugging computer from power
2) turning off ProTools, etc.
3) removing firewire drive
4) replacing the XLR cable with different/shorter one
5) turning off all lights in house (includes a dozen dimmers)
6) unplugging house WiFi, cordless phones, small stereo in same room
7) turning off furnace, ceiling fan downstairs, etc.
Strangely, if I hold my hand/arm a few inches above the mic, the ringing goes away, which makes me think it's more "in the air" than "in the wires," but what do I know! (With a prior cable, touching the end where it joined the mic stopped the ringing, but this newer cable isn't plain metal right there.)
So, should I start by trying to upgrade all my cables to more shielding? Add power conditioning of some sort to the circuit? Get an electrician to come and look for poor wiring? (or could I walk around my house with a multimeter and somehow check for current leakage in outlets and wall switches? how??) Turn off banks of fuses and see if anything drives it out? (then what??) The n-space for investigation seems huge, so I'd love to get some advice on where to start and/or how to block RFI.
The only other information I have is that we get poor radio reception in this room as well, but don't know why. (The furnace chimney may run behind the wall with our stereo against it.) Live in an urban area, room is on 4th floor of our house, attached to another unit on one side... Help!