definition for SPL and SQ?

what is the definition for SPL and SQ, when people talk about sound? also what is the difference?

SPL = Sound Pressure Level.  It is a measure of loudness with units of decibels (db).  It is also generally used to indicate car audio systems designed to be loud.  Every loudspeaker produces SPL.

SQ = Sound Quality.  It is a combination of objective measurements like frequency response and distortion and subjective judgements like imaging.  It is generally used to indicate car audio systems designed for accuracy.

damn, i guess if i wasn't such a blonde (actually have dark brown hair) i could've figured that out.

so basically SPL are for competitions and SQ is for people that care about the way music sounds?

yeah sounds like me. in my younger days, haha even though i'm only 20, i used to love to jam out. but now sometimes i just like the clear sound of music that i can get. don't get me wrong, there is nothing like the feeling of driving jamming to some hardcore rap bumping.

how do i go about deciding which one is right for me and how do i differentiate between the two when chosing components for my system? i want something that sounds good but can also hit like no other when desired. i'm not looking to enter any competitions or anything. just a nice musical experience in my car.

There is no real way to tell you which one to choose as it is all up to you, from what you are saying I think you want a mainly sq system with a little bump to it.  My answer for this is (and these arent the only brands and models to use but I would recommend these as I have had great luck with them and systems set up with all of this stuff together before), I would recommend getting some nice components up front, there are tons of good ones but the really popular and consistantly crisp sounding ones are brands like focal and mbquart.  I would say a nice set of 6x8s or 6x9s in the back, it will give a good balance of midrange and treble, I personally prefer Infinity for 6x9s and JL or Eclipse for 6x8s, but then again there are other brands.  My recommendation for an amazing sq sub that can really bang when you want it to would be the JL W3v2, if you have the space and money I would say go with the 12w3v2s in the powerwedge box (slot ported and built perfectly to spec, I love this box!), those subs sound beautiful and if you crank them up will blow away most other subs in their power range.  Once again these are only my opinions and suggestions, but hopefully this will give you an idea to build from.

alright, most of the stuff i had was from the first system when i didn't have as much cash and stuff so it was pretty simple. back then i just wanted to hit hard all the time. i had 2 12" bazookas and a bazooka amp.

now i have a 97 accord coupe. alpine cda-9827 HU. i still have the bazooka amp (el2100) and 2 12" infinty reference subs (1230w). they aren't in the car yet so right now all i have is the head unit. i'm thinking about building my own box for the woofers so i would probably just put new speakers in the car because i think two of them are blown. i'm more than willing to have this an ongoing project as opposed to have everything put in in 2 days or something.

as far as my budget i would like to spend no more than like 800. being in college i don't have that much money but i also want something that sounds good. i have a part time job but the hours will dwindle once school starts, studies over work for now. i was thinking about mb quart components up front and infinity kappas in the rear. possibly amping them by an alpine (40 watts x 4 rms). someone told me to look at maybe a JBL GT series amp for the subs. but if i could get it to the point where the interior speakers sounded alright, and hit alright, then i could wait until i have more money and time to put in the subs. the only thing about this though is the wiring, i would rather wire both amps (subs and speakers) at the same time that way i don't have to go back and re-wire and ish like that.

any suggestions are greatly appreciated.