Nightly Power/Noise Issues

Discussion in 'Microphones (live or studio)' started by Brian Ronald Jones, Apr 18, 2011.

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  1. Brian Ronald Jones

    Brian Ronald Jones Active Member

    Apr 18, 2011
    Chico CA
    At night, around the same time, all of the speakers in my studio start to make noise. It's a crackling noise, like a scratchy record, mixed with a little hum. I think it might start when the security lights outside the building come on, but at this point I am certainly not sure.

    When my monitor speakers are plugged into my Profire 2626 outputs, they make the noise, but when I turn the Profire 2626 on or off, just for a moment the noise goes away, and I get a faint radio signal, then the noise comes back on, and the radio signal goes away. RFI? However, when I have my monitors plugged into my Focusrite Octopre mkii, instead of the Profire 2626, the noise is there until I turn the focusrite on, and then it goes away completely. My brother's SWR Bass rig is plugged into a Monster Power Center, but it doesn't seem to help.

    Does anybody know what I should do to deal with this issue? It seems to affect all my power outlets. I don't know much about power filtering or conditioning, and since my brother's monster power center doesn't help, and my focusrite preamp does, I have no idea what's going on. Is this a ground loop? RFI? I don't really understand those... is this something that a UPS could fix? Do I need an electrician to figure it out? What do I do next?
  2. TheJackAttack

    TheJackAttack Distinguished Member

    Mar 20, 2008
    currently Billings
    Your security lights are probably sodium lights if they are commercial models. These create all kinds of noise on an electric line. Kind of like having a light dimmer switch which is hell on audio lines. I have also seen consumer security lights with motion detectors and photo cells for night/day automatic switching cause noise on electric lines too.

    Not all "power centers" are equal. Also there is the fact that speaker lines are unbalanced and can actively pick up EMI or RFI pretty easily sometimes acting like an antenna.
  3. GZsound

    GZsound Active Member

    Mar 20, 2001
    Near Portland, Oregon
    Home Page:
    You could try a UPS, but make sure it's a sine wave type.

    You could also find out if your power is properly grounded at your power panel. In theory, you should not be on the same circuit as the security lights, but you might get the hum just because your entire building is on the same main power circuit.

    As I said, try a UPS and see if that helps. Monster does make power conditioners that do more then just act like fancy surge protectors, but they cost over a thousand dollars to get a true "power conditioner".

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