John Sayers' Recording Studio Design Forum Archive

Hi -

I've got a studio in a commercial building in Los Angeles. I've got a noise in my recording chain (only present where there are preamps and phantom power happening) and I'm wondering if anyone can help me identify it before I go about troubleshooting. It would help me to know if I'm dealing with RFI, EMI, etc and maybe someone out there will recognize the sound of this immediately, then I can save a lot of energy and time by knowing how to find the problem!!

I've attached it below. I've pulled it up in my eq plug that has an analyzer and there are frequencies happening at exactly 1k, 2k, 4k, 8k… as well as that crackly sound…

How are you recording that? Sounds a bit like the typical interference caused by notebook power bricks. Got any of those around?

Or maybe old analog CRT monitors? Those things can also inject noise into ground.

By the way, I'm not seeing anything at 1K. The main tone there is a bit above 4k, but there's also harmonics and sub-harmonics, plus a few other things.

But I suspect that something else in the room is the root cause, and it is being picked up by a poor quality cable, or due to poor grounding in your room. Is the room wired for star grounding?

- Stuart -