Using EQ to Conquer Hum

By nature, hum-causing electricity in the United States has a fundamental frequency of 60Hz (hence the name 60-cycle hum) and harmonics of different volume at 60Hz intervals such as 120Hz, 180Hz, etc., running throughout the frequency spectrum. EQ set to any harmonic frequency of 60Hz can be used to filter out offending frequencies. It should be noted that the narrowest Q possible should be used in order to cause as the least amount of damage to the overall sound quality of the audio. Using a high-pass filter dialed in to 60Hz or 120Hz you can effectively reduce a good portion of the hum. Of course, on bass-heavy instruments, the high-pass filter could remove crucial low frequencies, and must be used cautiously. On a single-coil equipped electric bass, setting the high-pass filter to 120Hz would pull a substantial amount of the low end out, causing a weaker bass sound. But since it’s not uncommon to cut the bass at around 50Hz, a cut a 60Hz would probably handle any hum issues with little impact on the overall integrity of the tone. On the other hand, with an electric guitar equipped with single-coil pickups, the high pass filter could be set to 120Hz without causing substantial damage to the sound.