well the speaker box FINALLY got done and I actually covered it (on a side note Felt with spray adhesive makes a pretty nice box covering and really cheap too) anyways I put the 2 10's in the box and they dont hit as hard or sound as good as they did in the square box(14"x14"x26") they were in (bought it all used) my box takes up ever inch under the seat of a ext cab
BTW there 10" Kicker Comp VR's

 

did you have them in your truck in the other box?
could be diff air space between the old box and the one you built causing performance change. depending on install and direction facing of the new box/subs will also cause gains or losses.
sounds like you need to redesign and rebuild your box. you can get loud, deep, good sound from a box under the seat.

got any pics, i'll help you design something up if you like.

 

ill get some pics this week the box I built can not be any bigger it takes up every inch (and still fits under the back seat) its really close and it goes all the way to the ends (I even had to notch it where the seat mount is its so long) I did have the other box layed in the back of my truck but I hate the idea of not being able to use the back seat and I think it dosent look professional at all. the ONLY thing i can think that might be hurting me is a built braces inside the box and they dident allow much room for air to get though between the speakers because there in the transmssion hump spot of the box so I used a whole saw and drilled like a 2.5" hole and a 1.5"hole in them to allow more air to get threw maybe this isent enough...

 

your subs should have a dedicated air space you should design to. YOu need to match that air space to get the best performance. Also, each sub should have their own enclosure, meaning no air should move between the two sub spaces.

 

both same air space, seperated air space,.....doesn't matter.
subs firing different ways will have different response charictaristics. down fire is more boomy, downfire sealing the front face of the box to the floor and having the sound come out the rear, will be more boomy and hit lower notes. forward and up have better sq. you can fit a ported box under there too. subs up ports forward, subs forward ports rear. if you can glass the bottom of the box to fit the floor contour, you're even better off. there's a few links around of d.i.y.'s if you want to try it.just some things to think about.

 

Make sure they are wired right. Parallel, series. When the bass hits do they fire out, or suck in?

 

also if they are in a non divided box {sharing the same air space} make sure that you are running them mono. if not they will sound like

seth

 

what's the cubic ft. inside the box, if you don't want to rebuild the box, you might have to get more speakers that are made for that air space. I have two BRAND NEW never played alpine type R 10's that hold 1500W max each for sale or possible trade w/boot if your interested in goin that way.

 

well I played around with everything checked some wiring and it tuned it a little bette and everything sounds right... thanks for all the help guys

 

I agree with most of the other posts.

1. If the subs are sharing the same airspace, check the phase of each. (make sure both are firing in sequence rather than 180* out of phase. This is a common mistake.

2. If they are in a sealed enclosure, stuff the enclosure with a quality poly-fill. This will lower the relative Q of the enclosure, lower the tuning frequency. Look for a ~15% INCREASE in theoritical enclosure size as well (woofers will "think" they are in a larger enclosure). I think you may have the issue of not enough airspace.

3. I would suggest playing in mono as well if possible.

4. Check you pre amp outs from your head unit. Some of the head units have many sets to choose from. Some of these outs will only send front channel or rear channel or left or right signal to the amps. You want a full range signal (with the correct x-over as well).