Sealed Box too Big?
I purchased this dual 12" sealed box which has an internal volume of 1.34 cubic feet per chamber, because they are seperated for my two Pioneer Premier subs which have an rms of 1000W. Pioneer recommends .5 cubic feet at the minimum and 1.0 and the max. Could this be why my boom is so crappy? I have two very strong amps hooked up, one to each sub. They are Power Acoustik A2400DB's which have an rms of 1400W. Is this why my bass response is so crappy? Premiers are excellent subs and I've heard that a bad enclosure can make even the highest quality sub sound like crap.
By crappy i mean that the bass is low, not loud enough, the measurements I gave were 1.34 cubic feet on the inside of the box not the out. Yes, you were right when you mentioned the subwoofer, it must also take up some space in the box.
Be sure that what you measure is net volume, today subs has big magnet and structure and that takes space inside the box, so your 1.34 cu.ft box actual volume (subtracted by the sub's own displacement maybe close to 1 cu.ft)
You have to make sure that the box is properly sealed, any leak and the response will suffer. Have a kind of absorber inside the box, especially in the back panel, this will reduce box resonance and standing wave.
Check your amp's setting maybe you have the crossover point set to high or to low. Usually it's between 80-120Hz, depends on your component system's low extension.
Actually I'm a little bit confused here, what 'crappy' that you meant? Is it not low enough, or not loud enough, or what?
Oh yes, also check your deck's EQ setting, excessive EQ boost can also make the sound .... well ..... crappy 
Ok then. Pioneer reccomends between 0.5 to 1 cu.ft usually this mean that 1 cu.ft will give you the lowest extension and flat response. The 0.5 cu.ft will sacrifice the low end in favor of the peaky response between 80-100Hz and a little bit more increased power handling. This will add the 'punch' to the system, it will sound louder by 2-3db, and will be more likely to suit your taste.
Lets experiment with adding solid material's inside the box, like rocks or bricks, so some of the volume will be displaced. Start with 1/4 of the box listen the change, add more if you want more thump. After you find what you want, just measure the net volume of the box, throw out the bricks, do some calculations, and . . . just cut the box and make it smaller.
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