Phoenix Audio DRS-EQ/500 - Mono Class A 4 Band EQ for the API 500 Series - Manual (Page 5)

We have selected eleven switch-able frequencies, which we will be most used
for a variety of instruments and voices. The switch-able frequencies are :
HF – 15k & 10K
Mid HF – 6K, 3K & 1.6K
Mid LF – 800hz, 400hz & 200hz
LF – 130hz, 80hz & 40hz
Each of the four EQ bands has 16db cut and boost so its very powerful and
each click of the detented pots will equate to around 1.5db in either cut or boost.
How they are used in application settings could be like this :
Vocals :
Boost at 15k to inject some air into the vocal
Boost at either 800hz or 400hz
Cut at 3k
Cut at 130hz or 80hz
Acoustic guitar :
Boost at 10k or 15k
Cut at 200hz
Electric Guitar :
Cut at 130hz
Boost at 200hz
Boost at 6k
Cut at 10k
Drums :
Kick Drum: HI-PASS, Boost 80hZ, Cut 400hZ, Boost 6kHz, Cut 10kHz
Snare Drum: HI-PASS, Cut 80hZ, Boost 200hZ, Cut 1kHz, Boost 10kHz
Rack Tom: HI-PASS, Boost 130hZ, Cut 400hZ, Boost 6kHz, Cut 10kHz
Floor Tom: Boost 80hZ, Cut 800hZ, Boost 6kHz, Cut 10kHz