Post by cbdroege on Mar 27, 2017 3:25:07 GMT -8
Inspired by the "how to remove noise" thread to share this tip that I had to learn the hard way. 
Go through all the normal diagnostic steps in your environment and equipment before jumping to this conclusion, but another thing to consider if anyone has some still undiagnosed noise issue:
It's rare these days, but if you're recording in a building with old, unshielded wiring, it can be picking up noise from the ambient EM interference in the environment, especially if you are also near power-lines or a neighborhood transformer box. This is tough to diagnose and deal with because it's not noise that you can do anything about in the recording space, since the power system of the building is transmitting it directly to your recording device by the electric current. It comes up in the recording as constant buzz.
Luckily: If you have this issue, it's usually easy to fix. Instead of using the 'noise removal' feature of your editing program, use a filter that removes just a specific frequency from the recording (notch filter). Unless the building also has dirty power (which, at that point: why are you recording in an old abandoned warehouse on the docks?) the buzz will be at a specific frequency and have very little variation, so removing just that one frequency can clear up the whole recording, even from under your performance (unlike the noise removal tool). You'll have to do a little bit of trial and error to find the exact frequency, but in the US it will be very close to 120, since that's the frequency of power transmissions in the US. If you change your set-up, it may affect the frequency coming through again, and you'll have to search for it again, but once you find it, it'll sound like magic has cleaned the recording.
As a side note: If your building wiring is picking up a nearby radio station broadcast, you are SOL. Either replace the wiring in the building with some shielded wiring, or find a new place to record. You'll know right away if that's your problem because, if you turn up the gain, you'll hear the actual radio broadcast inside your recording. Yes, I've had this issue before. ;D I was helping set up a radio station booth, and it turned out their building was just down the hill from the broadcast tower for the local NPR affiliate. They had to find a new building...
Go through all the normal diagnostic steps in your environment and equipment before jumping to this conclusion, but another thing to consider if anyone has some still undiagnosed noise issue:
It's rare these days, but if you're recording in a building with old, unshielded wiring, it can be picking up noise from the ambient EM interference in the environment, especially if you are also near power-lines or a neighborhood transformer box. This is tough to diagnose and deal with because it's not noise that you can do anything about in the recording space, since the power system of the building is transmitting it directly to your recording device by the electric current. It comes up in the recording as constant buzz.
Luckily: If you have this issue, it's usually easy to fix. Instead of using the 'noise removal' feature of your editing program, use a filter that removes just a specific frequency from the recording (notch filter). Unless the building also has dirty power (which, at that point: why are you recording in an old abandoned warehouse on the docks?) the buzz will be at a specific frequency and have very little variation, so removing just that one frequency can clear up the whole recording, even from under your performance (unlike the noise removal tool). You'll have to do a little bit of trial and error to find the exact frequency, but in the US it will be very close to 120, since that's the frequency of power transmissions in the US. If you change your set-up, it may affect the frequency coming through again, and you'll have to search for it again, but once you find it, it'll sound like magic has cleaned the recording.
As a side note: If your building wiring is picking up a nearby radio station broadcast, you are SOL. Either replace the wiring in the building with some shielded wiring, or find a new place to record. You'll know right away if that's your problem because, if you turn up the gain, you'll hear the actual radio broadcast inside your recording. Yes, I've had this issue before. ;D I was helping set up a radio station booth, and it turned out their building was just down the hill from the broadcast tower for the local NPR affiliate. They had to find a new building...
