I'm running two of these subs in a 97 Maxima off an Orion XTR900 amp. They are bridged mono in a v-shape box through the arm rest. The RMS is rated at 600 watts each sub, I'm pushing close to 900 to both. They seem to bottom out easily when playing very loud and deep bass. That ****es me off. The enclosure was made to EXACT A/D/S specs. 1.1 cubic feet total space for each sub and polyfill. I also have a subsonic filter set at about 25hz. Please help me figure out what is the possible problem with my install, or these subs simply cannot handle the power I'm giving them? Here is a picture of my box. Thanks
http://images.cardomain.com/installs...7_195_full.jpg

 

1.1 cu ft for EACH sub?

a/d/s specs the box at 0.5 cu ft minimum, and if you're running more than double that, you'll have tons of problems with midbass and too much excursion at higher power...
the box is just too big to control the sub.

try stuffing some styrofoam blocks or chunks of wood inside the box to bring it down to about 0.6 cu.ft per speaker, then see how it sounds then. I'll bet that fixes your problem.

 

Matt, I spoke to Pat, the head tech support for A/D/S and he is the one who recommended such box dimensions. As far as midbass goes, the sub is crossed over at 63hz/24db and it still seems that it's crossed over too high. Also, it bottoms out on low powerful bass notes. What to do, what to do....How much smaller should I really make it and still have excellent sound quality.

Anton

 

Anton,

I think a/d/s is just a little overzealous in saying that the subs can handle 300watts per coil. Also, are these dual 4 ohm, dual 8 ohm, or what? Don't forget ohms law. Two 4 ohms coils bridged = 2 ohms. four 4 ohm coils bridged = 1 ohm. Now connect that to a bridged amp and it sees it the same way as it sees a stereo 1/2 ohm load. That's prety damn low. So the amp may also be overloaded. Also, as Matt said, a large box lowers the power handling of even high performance subs. A small box can extend quite low into the lower frequncies in the car. That's why 6 1/2 inch mids have such great midbass.

 

i see one possible problem! you have both subs firing into each other canceling out certain frequencies and sound waves. Try firing one into the box and leave the other alone.

my.o2

 

jsut try the styrofoam thing, or stick some wood blocks in it.. it doesn't cost but a few pennies, or trip to the scrapwood pile.. (be sure to glue/screw the wood in place before driving!)
but it'll only take a little of your time and very little money to find out if that's your problem or not. if you don't like the way it sounds, pull it out and try something else.

but I'll put my money on the box being too big. VAS on those things was only 1.6 cu ft, and "usual" box volume is waay below VAS. i.e. you should try about 0.5 cu ft each and see how that does.

 

Yeah, with that much power to a voice coil that small I wouldn't drop the box Q below 0.707. So that means about 0.63 ft cubed net per sub. And I would double check your crossover settings, and measure the actual crossover frequency with a frequency counter if you aren't sure by ear that the X-over is working properly. Then double check your level settings on the amp, all the settings(the 10dB boost in particular). I once had a boost **** cranked all the way to the right when I really wanted it cranked to the left. Can't remember how I did that, maybe from laying on my back in the trunk. But it sure didn't help my 5 1/4 mids.

450 X 2 @ 2 ohms stereo. And delivering this with only 60 amps max current? Most fuses will take a momentary peak up to but not exceeding twice the rating. 120 X 12 = 1440 x 60% efficiency(this is optimistic) = 432 max watts per side before blowing the fuses. So, you probably don't have too much power.