Hi, Need experienced help, I just received and installed my Fi SP4 15 D2, powered by a Crescendo B3500D(the volume on the amp is up to 75% on the gain knob on the amp and bass boost in 0 and on the head unit the subwoofer level is in max), and I feel the bass is weak for what I expected...

1- Is this normal? Or what should I do?

2- Is there a specific way to put the ohm load down to 1 ohm on the sub?

3- What specific grill fits this sub?

Thank you.

How did you wire it?

if that isn't loud then you got something wired up or installed incorrectly. we need more info on box specs. also verify that the subwoofer is wired in parallel to 1ohm.

a grill for this sub would probably require some fab work. perhaps counter sinking the sub and using something like this so that the surround doesn't impact the grill. http://compare.ebay.com/like/170906147213?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar

Where did you get the enclosure?

what is the box tuned to? how many cubes is it? is it ported or sealed? how is it wired on the sub and what kind of electrical do you have?

I have a flare ported 3.5 cubic feet box, the sub it's wired positive to positive, negative to negative and from there to the amp, I have good and the recommended electrical in my car.

What size port? What electrical?

I think it's 6 inch, I have a kinetic 2400 in the back, the big 3 and a 160 amp alternator.

On the amp:

Where is you subsonic set at?

Where is your crossover set at?

What is the model and name of your hu?

Does it have have on/off for the sub controll? Does it have have a sub low pass filter?

Did you buy the amp new?

subsonic: all the way down

crssover should be around : 80-100hz

its an jvc hu and yes the sub control volume is at max

yes the amp is new

double check every thing. Also make sure your rca's are connected properly.Maybe you are getting your subsonic filter and crossover confused. double check that as well.

Make sure your grounds are clean and solid. Lots of people overlook a bad ground.

Subsonic needs to be set 2-3Hz below your port tuning frequency.

Ok, what exactly is the subsonic for?

Subsonic is like a high pass filter, it plays frequencies above the set point and attenuates frequencies below to prevent damage to the sub in the box.

OK, that's what I thought, thanks.

you didn't check your impedance to the amp? I would turn your gain down now, and save your equipment before you figure this out. If you are hooked up - to - on the sub, you are not @ 1 ohm. On a dual 2 ohm voice coil you need to wire + to - and + to - on the other side. + out to amp from one side, and - out to amp on other side. Check wiring diagram at the12volt.com before you get stuff rolling again.

you didn't check your impedance to the amp? I would turn your gain down now, and save your equipment before you figure this out. If you are hooked up - to - on the sub, you are not @ 1 ohm. On a dual 2 ohm voice coil you need to wire + to - and + to - on the other side. + out to amp from one side, and - out to amp on other side. Check wiring diagram at the12volt.com before you get stuff rolling again.

Thats 4ohm you have stated. He has it wired the rite way.

Dual 2ohm voice coils wired in parallel= 1ohm

Edited February 8, 201312 yr by jj1479