So where should i start to adjust the sound/EQ?
I have a Eclipse AVN6620 and there are so many adjustment i dont know where to begin. To be honest i dont even know what some of the settings mean.

TruBass ON/OFF?
Harmonizer LOW/HIGH/OFF
Loudness ON/OFF?
I also have like 7 HZ bands
Q-curve pattern WIDE/NARROW/Normal

Now for the subs i have
Woofer Output Mono/Stereo
Phase Control Normal/ Reverse
Cut of Frequency 63/80/100/125/160/200Hz
then there is a button for each 6dB/oct.....12dB/oct....PASS

So if anyone has a clue please educate me!!

just play with the different options until you find a sound that you like thats what i did.