ok i've almost got my system done, but my subs dont sound like i want them too. i built a blow thru for 2 15's, which are in a 5 cube box(too big?) and they fire into a 3 cube chamber that vents into the cab thru a 8x43" opening thats 4" long. i guess its basically bandpass with an external port. the problem is that the subs wont play low, they hit really hard but lack the bottom end grunt, i'm sure my old tens had more bass you could "feel" if you know what i mean. what could i do to help this? even with the x over set at 20 hz (lanzar 1200d amp) they just dont play low. btw the 5 cube chamber the subs are in is sealed.

What subs are they? I did a pass through in a full size chev with 2 15" MTX T61544A's, they were each in a separate 3.5 cubic foot enclosure tuned to 30 hz. It pounded and was actually the "tightest" bass I have heard in a long time, they sound awesome with punk rawk. I made sure the opening I cut was at least equal to the cone area and port area added together.

ed 15k's. the subs are in a common chamber. its tight but it just seems to have a real peak, almost annoying around 70hz, and not much output below that

Well I cetrtainly wouldn't want some random tuned bandpass in my car, I would make sure that the cutout from the cab to bed has at least the area of the cones if not more open. What is the recomended box volume for those subs? With sealed boxes a generall rule of thumb is that in a smaller space (interior) the boxes have to be bigger and in a bigger space (interior) the boxes can be smaller for a given response.

so i guess i should rebuild the box. but i already am at max opening

Do you have pics anywhere?

i have pics(drawings) of what it looks like now

hey Anthony, sorry i didnt get back to u in a while. school stuff just flooded my email account so i lost track of all the incomming male.

this is what i would do. you said your subs a 6 inches from each side so that gives u room to put in a 4 inch port on both sides between the sub and the side wall in your 5.5 cube box. the ports would have to be 9 inches long each. that would tune u down to about 32hz and should pick up low notes much better.

so the front of the 5cu box would look somthing like this
http://members.rogers.com//box15ported.gif

ports go on both sides between the sub and the side walls. 4 inches in diameter and 9 inches long. if u can try to find some aero ports/flared ports to use. if not regualr 4 inch pvc pipe will be fine.

^^^ hey no problem, i kinda forgot about you as well, been busy with work and crap. but i will pick up some pipe today and give that a try.

well i did it and it works awesome, it sounds so much more powerful now, like 15's should, thanks a bunch man. just some fine tuning with crossover and eq and i'm set. the only problem now is when i turn it up, everything goes blurry lol [img]smile.gif[/img]