Audio Systems: car audio, kicker amp, musical sound quality

Question
03 nissan frontier, aftermarket system.... kenwood kdc-mp642u head unit, two set's of kicker ks650.2 component speakers on zx400 kicker amp 4ch, two 8" kicker L7's on kicker zx750 mono amp, 1500 watt sunami cap. want to figure out the EQ on head unit for best performance on component's love lot's of treble the more the better but i want to crank it up while keeping speakers within there range.

Answer
Setting the eq is totally subjective in car audio systems.  Even the very best auto sound is not suitable for scientific balancing due to the sporadic and non-uniformity of the acoustic space.

Best way is to take at least 5 tunes on your favorite CDs or mp3s and choose

-  Male voice solo
-  Female solo voice
-  Music only, no voices - of your choice but with lots of range and dynamics.
-  Music with lots of bass sounds.
-  Music with lots of treble sounds.

If you choose tunes that you like and represent the range of dymanics and musical sound quality they will guide you.  Play each one and set the eq for the best sound to your ears.  Go back through them multiple times until you find the best settings for the sound quality you are aiming for at the different levels you want to hear them at.

You may find there are different settings that you like for each type of music. Nothing wrong with change the eq to match the sound you are looking for.

In the worst case you may want to switch speakers or add tweeters to the system  (or subwoofer, etc.) to get it where you want it.

Have fun.

PS:  You should go through the audio level setting sequence as well making sure you have all your speakers balanced with each other. See page 28 in the manual.

Page 31 gives the setup procedures for manual eq adjustments.  They are pretty broad bandwidths for doing any serious fine-tuning of the aduio.  For a purist, like myself, I look for setting everything for the overall flat response. In your case you want more treble sounds so you must adjust band 3 area for the 4k Hz and up to enhance the treble.   Actually, treble is considered above 1,000 Hz.