Today was a day for work away from the internet–working on Free Will pacing notes (a book this big? The pacing can get delicate), and finishing the buzz hunt in the studio.
About a year and a half ago, right toward the end of DF10, a nasty new buzz crept into my recording studio. Straight, evil, 60 cycle nastiness from hell. I got a couple of workarounds to finish DF10 and do the first few eps of Free Will, but the amount of time it was taking me drove me bonkers. All the other recording I did during this time wound up happening at other places, because trust me, you could *hear* this. Even if I buried it in background foley, it was nasty.
But because writing new material was higher priority, and all the voice work I had in the meantime was low key enough to do on my mobile rig at a friend’s house, I put off dealing with it.
Until today. I had some new equipment going in inline, and that’s as good a time as any to check every cable connection and power outlet in the place.
After going over everything, and finding no reason for the buzz, I had a friend over who’s done a good bit of electrical engineering. It took him about ten minutes to double-check my work and discover what I hadn’t: that on the high tension wire pole outside, an antique transformer had gone on the fritz, and it was throwing off EM like you wouldn’t believe.
I asked him “So, other than moving house, what can I do?”
He showed me a trick that is so head-smackingly simple, I figured I’d pass it on in case any of you are running into similar problems. He used one of my dynamic mics to map out the magnetic field. He hooked it up to the board, boosted the frequency with the buzz, and started sweeping it around the room. Once he got the shape of the field, he started twisting the microphone.
One of the things you look for in a good dynamic mic is excellent side and back rejection. Turns out this works for magnetic fields as well as for sound. Once he got the shape of the field (which confirmed his suspicion that it was coming from the transformer outside), he positioned the microphone so it’s hind end was pointing in the general direction of the transformer, then he handed me the headphones.
No buzz. Not even a little bit. He said “Now, if it bugs you again, check the orientation of the microphone, then just change the angle until you aren’t getting a buzz. This should work with just about any pro mic you’ve got.”
So, if you have ground buzz that you can’t identify, try looking out the window. Or, just try changing the angle on your mic. Sometimes, really really silly things can fix major problems.