well, i'm in the process of building my crx, so this is what i'll be shooting for.

i want to use a single 10" but a friend told me a 12" would be better. now by the look of how this set. they are running two amps, one per coil. so since if my sub is RMS is 900 watts 2 - 400 watt RMS amps should be fine?

what i'm looking for is like a blueprint of some one doing the same type of box(or a link). my friend said to use fiberglass, i've never used fiberglass before. so i'm really not trying to do it that way but if i must... any help would be helpful.

 

The above is a 4ch amp, [right] driving front and rear speakers, and a mono block sub amp, [left] driving the sub.
And the above is not a CRX, or it's the first one I have seen with 4 doors.

Because of the lack of room in a CRX the spare tire well fiberglass sub box is the best way to go, if you have not done fiberglassing before, there are more then a few tutorials you can Google up, and I would practice a little on something other then your car.
There is enough room in the spare tire well to build a MDF sub box, for a single 10" even a single 12" sub with out raising the floor more then 1" - 3", [depending on sub, IMO a 10" is all you need for your CRX, amp rack can be built where the rear security tray is. 94

 

i know it's not a crx. it's the skunk2 fit they did for the street tuner show or so. but i liked the way the system was done. so i was shooting for almost the same set up. and i was thinking about doing a different set up. which in i wanted to see/hear how a two amp on a DVC sub sounds.

 

Although you can use two amps to drive a DVC sub, it is not recommended, unless the amps are strapable, the output on two diff. amps are not exactly the same, and problems can arise, it is also not necessary unless you have a MTX Jackhammer. 94

 

uh i will have a little problem w/weight if i could fit a MTX Jackhammer. lol. but hey man thanks for the advise.