so i currently own a 12in alpine sub. i'm thinking about going with a 10in sub, but i wanna make sure that if i do i get something with good quality. Please give me your suggestion. Also, please show pics of your sub-woofer setups.

 

i went from a 12 type r to a 10 type r, i cant hear much different really and alot is going to depend on your box

 

I highly agree.
Box design has a HUGE impact on the performance of the sub. For example, a ported enclosure designed specifically for the woofer is going to be CONSIDERABLY louder than the average sealed enclosure. Unfortunately, it is also going to be much larger than the sealed enclosure, which limits its installation location possibilities.
You want to have an idea of what you are aiming for, then tailor your setup toward that goal.
For example, I built my sub setup mainly to give me the low ended, tight, quick thump associated with a kick drum as I listen mainly rock and jazz. I also have a 5 gal. air tank in the back hatch area with my amps in a false floor off to one side and I didn't want to build my sub over the top of it all. I also wanted to bring the sub as far forward as possible to keep the sound image as realistic as possible. I ended up building a sealed 10" into the back of a custom console so that the 10" sits directly behind and between the two front seats.
What I ended up with is this: (please pardon the dust. The pics were taken when the console was installed and I hadn't cleaned everything up yet)

 

clean set up, if you like alpine stick with alpine,ive got type-r's and like em

 

the alpines are clean and not over the top

 

2 dvc 12"s in a ported box with a 1000w memphis amp go hard, real hard

 

if ya want a10 and still have room but have clean sound id go with a jl audio w3 ,10 good price great sound small size go to a shop and check it out you will be amazed from it..if ya want to go ***** out then go with the top of the jl audio w6/7 ...here is a link to the 10 if ya ask me jl audio is one of the best out there..dont go cheap you will regret it ..

http://www.shopatron.com/products/pr...r=92151/1451.0

 

i have memphis and love them i have the m3s

 

Sick

and best advice....plenty of 10's outperform many 12's. You did mention you wanted SQ vs SPL is that correct and what is your budget? matching your components specs is key what amp are you going to run and what size enclosure/type do you want to use?