Audio Systems: pioneer deh-p7750mp, pioneer deh, pioneer headunit

Question
i have a pioneer headunit (deh-p7750mp 50w X4).im struggling to set the equalizer settings.the sound(bass &midrange) sounds very hollowLbut wen i try remedy this the high pitched soundsL especially vocals wit t's & s's start 2 distort(like the singer has an extreme lisp) oh...& the speakers are  standard midrange doorfitted speakersLill be doing a full upgrade on the sound peripherals within the next couple of months

Answer
well my friend, this is one of the problems with EQs.  to make a long story short, they're only good if they have bands at the same freqencies where you have problems.  and to make it worse, if the bands are too far apart, they will have a tendancy to drag alot other freqencies along with them.  Eqs dont just adjust the 1 freqency that they are set to, but a range of freqencies, often stretching all the way to the center point between it and the next eq band or further.  so for instance, lets say you have a 4 band eq. with settings at 100hz, 1 khz, 5 khz, and 15 khz.  and lets say your 6khz in music is too loud but your 4 khz is too soft. what do you do?  chances are, your ear will hear the harshness of the 6khz being too loud so you'll reach for the closest band that your eq has, which is 5 khz, and pull it down.  so now you've fixed the 6 khz being too loud problem but you've also pulled the 4 khz down even further and that was a problem already, so now you've made that worse.  
most of the time poor quality speakers, like the ones found in factory setups have very sharp, spikey responces that simply cant be fixed with any eq.  most often the solution isnt tweaking the eq but changing the speakers.
I had a friend once that struggled setting an EQ for days and came to me to set it for him and as soon as I heard his system I realized he simply needed a set of tweeters.  he kept trying to compensate for something that the EQ just couldnt do and he would just ended up frustrated cuz it would just make everything sound worse.
I'm not saying EQs are useless by any means but they have their place, and thier limitations.  the only EQs I would say are useless are the ones that are "factory preset" eqs  YUCK!!!  these are the ones that say "rock, pop, jazz, etc"  these are useless and the best setting you could ever put this on is "flat" usually!

if you are unhapy with the quality of your sound, I would say that you've done a good job so far by getting this CD player, next step may be to get a good set of component speakers like the polk DB 6500's UP FRONT only! not in the rear (if you want me to explain just ask) and maybe even an amp to run them, depending on your listening prefrences, etc.

let me know what you think and get back to me.
looking forward to hearing from you.