How do I filter out single coil hum? Do I use the notch filter, and if so, where do I need to set it?
I sympathize, as I love P90 pups, and they are horrible for hum pickup.
If you are in the US, hum components occur at multiples of the 60 Hz AC mains line frequency. The most predominant is usually 120 Hz. (100 Hz in countries with 50 Hz AC line power).
If you wish to filter at recording time ("live"), using a parametric or graphic equalizer: This will probably effect the sound of your guitar/bass tone in an undesireable fashion. A better option to this would be a noise gate, though a gate works best with "louder" material. Orientation of the instrument can help greatly, as well -- stay away from flourescent lamps, your amp -- anything with a power supply, situate the player in the orientation that minimizes the hum.
Post recording, you may be able to use some good audio editing software (Adobe Audition, nee Cool Edit Pro 2) that offers high Q (narrow/fast transition) filtering, and set this to a 120 Hz (or 100 Hz) notch to knock down the hum by 6 to 20+ dB. Again, you may affect the sound, but in the software world you will have much greater flexibility, as you can choose the amount and type of filtering (e.g., FFT, FIR, graphic, parametric ...), redo as necessary and/or choose to filter only the passages where the noise is evident.
A lot is possible with patience. Good luck.
-=tension & release=-
thanks.
How do I filter out single coil hum? Do I use the notch filter, and if so, where do I need to set it?
First, (unless you're using an LCD type) turn off the computer monitor, and see if the bulk of it goes away.
Next, stand in place and slowly spin around, listening for the spot where the hum is lowest, or fades out completely. If you don't have it completely gone, take a few steps in the direction of the lowest hum level and see if it will fade completely out. When it does, mark the spot and note the direction you need to be facing ( a square carpet scrap with an arrow on it works nicely for this). Stand there to record.
Notch filters can help, but the best thing is to minimize the hum as much as possible before applying any EQ or "mix fix" solutions.
