How to properly set gain?

Okay once I have all the equipment in my vehicle, how do I properly set the gains on both the sub amp and the mid/highs amp.  I burned a test CD with frequencies from ranging for 20hz to 20Khz.  What frequencies need to be used to listen for distortion? In the subs and mids/highs?

Thanks fr your help.

400 Hz is comfortable to listen to (not too high) for the mids, and 50 Hz is a good one for the sub bass.  But you've got several, so listen to several.

Start with the head unit because this first part is critical.  A lot of folks assume 3/4 on the dial is right and proper and start there without listening for clipping.  Use the tones for this part as much as you'll use them to set amp gains.  At this point the amp gains must be turned to minimum.  Once you find that place on the deck where the tone changes to a clipped signal (you'll hear it best if you've recorded sine waves), you'll use that point as maximum signal strength to set amp gains.  And you'll know to never turn the dial past that point when playing your music.

Assuming you used a program that allowed you to set the sine wave tones at 0 db, you are good to go.  Because recording tones at any level below that may be lower than some of your music sources.

After setting the deck level, choose one amp or the other and choose a frequency in the range of the speakers you will be listening to.  Play the tone and turn the gain, stopping when you hear the clipping and turning it back just enough so that the sine wave sounds clear and clean again.

Manipulation of fader control, or removing/changing input RCA's will be necessary as you move from one gain adjustment to another.  Be sure to set the crossovers after the gains have been set.  I hope you've recorded tones in the range of the sub-to-mid crossover setting.  I use tones in increments of 2 to 3 Hz for that so that I can hear a change at a specific frequency...like if I'm using 80 Hz for the xover, I'll have tones recorded at like 72,74,76,78,80 (of longer duration), 82, 84 etc.