Amp tuning question

[SDMorris]

Quick question. My amp has three different tuning options, the Frequency knob, the EQ knob, and the gain knob. I know the gain knob controls the power of the signal to the subs, but im not really exact on what the other two do exactly. Im sure its pretty simple and a dumb question but I figured I'd ask.

The thing that brings this up, is that sometimes when I work on my system where I take the amp out or something like that, I always turn my gains down completely and re-tune by ear for safety. But I notice when I do this, all songs sound different again. Like notes that were really loud before in certain songs, are much quieter, and some notes in songs are way louder then before. Im assuming this has to do with either the EQ or Frequency gains on my amp.

Thanks for the help!

[7jezuz7]

I don't know about eq but the frequency one should be so that you could set a cut off frequency which is usually at 80 hz. Or it may be a subsonic filter in Which you would have to set it to a little under whatever your box is tuned to.