dawsonaudio said:
I should say that my studio wiring is looped around all four walls. Not sure if this is causing a magnetic "loop" of some kind which is creating this weird interference. Considering eliminated electrical wiring in all four walls and having all power terminate on one side closest to the subpanel. Not sure if this will help eliminate some interference.
It's not that weird. Clearly it's mains. The more current running through the wires, the greater the magnetic field. The ideal arrangement is to minimize high current devices in areas where microphones and guitars and other coil based devices will be used. And, wherever you must have power, you want currents to return very close to the path from which they came so that the fields cancel. And shielded cables power cables (called BX here in the US) might help too.
So you want to get away from any high currents. You suggested you're next to a panel in a garage? Is this for a house? There may be no solution for that. All of the current for refrigerators and AC and TVs and such throughout the house are going to be going through that panel. Do you have a basement? If the panel is in the garage then a basement with no panel is even better.
It might help to re-arrange wires. Don't plug things into different wall sockets. If you have a heavy duty socket directly connected to the panel, then attach an equally heavy duty cord to that socket and run it some distance over to your desk with the monitors and such. At the other end of the cord put a heavy duty 4 socket floor box. Then attach extensions and power strips that fan out from that one point. Try to power all gear that will be patched together to the same branch point. Meaning try not to connect ground loops. For example, if you have a guitar amp connected to one power strip and a rack effect unit on different power strip and then you try to connect the send of the amp to an input of the effect unit, you now have a big loop. If there's any difference in grounds or if there's a lot of noise on one ground (more current means more noise) that loop can cause noise.
Also try running separate cords from the panel to high current gear that doesn't need to interconnect (meaning differences in ground potentials won't matter as much). Guitar amps would be a great candidate for example. You might also try a separate line for your monitors. Technically you will of course interconnect to your board but if the interconnect is balanced, it may pay to power them separately but share signal ground.
So with some careful re-arrangement you might be able to make things better. Build it up incrementally and see what causes noise. Start with a mic-pre and a headphone amp and turn everything else off (especially computers).
The best possible solution would be to put computers with fans and high current stuff like monitors in one room and then you have a bundle of cables into a very quiet place with no fans and accoustic treatments and no high currents.