Noise During Recording: Part 6

Electrical equipment connected inside your home can throw noise into your power system that can then make it into your recordings. This is called AC line noise. The most common offenders are refrigerators, HVAC, fluorescent lights, and dimmer switches.

Diagnosing AC Line Noise

Line noise can have a wide variety of sounds, but it is always tied to the operation of the piece of offending equipment. If the noise only happens when your fridge turns on, you’ve found the problem. But don’t throw that fridge out just yet! There’s a better solution.

Fixing AC Line Noise

1. Buy a high quality studio power supply with signal filtering from a company like Furman or the like. Don’t go for the cheapest option; we need quality signal filtering here, not just surge protection, and you’ll have to pay a little extra for that.

A good quality signal filter in your studio power supply is very effective in preventing AC line noise. I like to make sure that my entire studio, all of the gear, is all running through the same master filtered power supply. If you do this, you can solve most ground loop problems and any AC line noise issues while using a single piece of gear. Two for one!

2. Try not to have your home studio running on the same circuit as a major appliance like a fridge or a dishwasher.