Noise During Recording: Part 7

For our final chapter on noise in the recording studio, we’re talking about RFI, or Radio Frequency Interference! Radio Frequency Interference occurs when noise from airborne radio signals moves into your recording equipment.

Most professional quality cables and components are shielded to prevent this type of interference. But, if your cables are old, broken, or of low quality, or if you’re buying the absolute cheapest recording gear possible, this type of noise could be a problem for you.

Diagnosing Radio Frequency Interference

RFI can make a variety of unique sounds that don’t sound like other types of noise. These include audible conversations, picking up radio stations, bursts of static, clicks, and pops. The “hashing” sound of an active cell phone being held near a speaker is an example of RFI.

Fixing Radio Frequency Interference

1. Keep cables carrying audio signals at least a foot away from any power supplies, radio transmitters, or transformers. Distance from the source has a big effect on RFI.

2. Stay away from radio stations, AM radio in particular.

3. Use balanced cables as often as possible within your studio. These days, the only unbalanced connections you should see is between an instrument and its amplifier.

4. Cell phones off or on airplane mode while recording.

5. Identify the source component accurately. The trickiest part with RFI is identifying the specific source of the problem. Isolating the one unshielded component that’s allowing RFI interference into your system can be tricky, but the actual solutions are usually very simple once you’ve done that. A small piece of aluminum foil wrapped around an offending guitar pickup or amp tube can be an effective solution.