Whether you’re wiring up a project studio at home or hooking up your guitar, keyboard or PA at a gig, hum is your number one enemy. Besides checking for ground loops and making sure your audio gear is connected to the same electrical circuit, you need to pay attention to your cable runs.
The main thing to do when routing signal and data cable is avoid AC wiring. We know it’s tempting to run all your cables – audio, digital and AC – neatly in parallel along the baseboards to your monitors or other studio gear. And it’s equally tempting onstage to clump mic cables, effects sends and AC power under a single strip of gaffer’s tape. But you’re asking for trouble! It’s much better to run the AC around the room in the opposite direction, and to have two separate cable paths onstage.
If you must route the cables along a parallel path, keep them separate. We’ve heard several differing views on the minimum separation between parallel runs of AC and signal/data cabling – anywhere from 6 inches to 4 feet, depending on the source. Contractors doing fixed sound system installation try to keep 6 inches between the two. However, some sources claim that AC wires produce a field 18 inches out from the wire.
If your AC and signal cables must cross, it’s best to let them intersect at a 90-degree angle.