These frequencies are the lowest audible sounds humans can hear. Normally heard in a bass, sub-bass, or low-pitched drums. Boosting these frequencies can shake a room or a car and they can be heard from far away. That can be cool, but too much boosting will make your mix muddy and undefined. It’s hard for our ears to pick out individual notes in super low frequencies, so use this region with caution. On an amplifier or speaker system, these frequencies would be heard via a subwoofer.
- Lo Mid (80 Hz to 320 Hz).
These frequencies are resonant and pleasing to the human ear. A lot of producers boost the Lo Mid on drums to make them “pop” a bit more. Melodic instruments that fit this range include cello, bassoon, baritone and tenor saxophones, trombone, and the low notes of a guitar. On an amplifier, these frequencies would be controlled with the bass knob.
- Mid (320 Hz to 1,280 Hz).
These are the frequencies that humans hear the most clearly. As a result, boosting the Mid can almost have the same effect as simply boosting the overall volume. If you want a particular instrument to cut through a mix, boost the mid. But be aware that too much Mid-boosting will tire the ear and overwhelm the listener. On an amplifier, these frequencies would be controlled with the middle or mid knob.
- Mid Hi (1,280 Hz to 5,120 Hz).
Mid Hi should be boosted sparingly because this is the frequency that can be most damaging to the human ear. When boosted correctly, the Mid Hi will produce a chime-y, bell-like sound. The Mid Hi is also the frequency that sounds most like distortion. This can be a great effect for intense, fuzzed-out keyboards or guitars. On an amplifier, these frequencies would be controlled with the treble knob.
- Hi (5,120 Hz to 20,000 Hz).
These frequencies are among the highest that the human ear can perceive. They range from stinging and annoying (in the lower part of this range) to ambient and atmospheric, as though you’re hearing background wind or surf (on the upper end of this range). A lot of producers dip the lower Hi so that nothing sounds too piercing but boost the super high frequencies to create atmosphere. On an amplifier, these frequencies would be controlled with the presence knob.