drivelikejehu

a bunch of stereo stuff came in my car and im not too happy with what it sounds like. need some suggestions on what i should do.

Problems:

theres very very little bass coming from the sub, and everything 100hz+ is going to the 4 speakers in the cabin, which makes me think the sub is way underpowered?

i get a terrible hissing sound in the backround of every song, even on the radio. (the power to the amp is running right next to some signal cables?)

drivelikejehu

Car came with:

Sony XR-C720 head unit
Sony XM-4045 4/3/2 channel amp (dont know wattage)(can it power 5 speakers liek this??)
a Tri-Mode Crossover with two leads in from the amp, and three leads out (one to the sub and 2 to front speakers) (other two leads from amp go directly to other 2 front speakers)
Powering:
Polk 5.25 2 Pc. system (4ohms)
Bazooka T-82s

Stuff I have:

Rockford P4004 1200watts 4/3/2/1 channel
2 Rockford P2S04 12" stage 2 (4 ohm) subs (theses are WAY too big for my car anyway, i dont plan on both being in there)

i was thinking of running the four front speakers on the Rockfrod amp, and the bazooka sub on the Sony amp alone, but the front speakers are 4 ohms each, can I do this? (the diagram for powering 4 speakers with the rockfrod amp says each speaker is getting a 2 ohm load)

or poweing the sub and 2 front speakers off the Rockford amp and 2 rear speakers on the sony amp, but i run into the same problem with the impeadance. (2 ohms to the front speakers and 4 ohms to the sub) is there anyway around this?

AustinCustoms

The problem is simple. They put cheap sony stuff in there. But it should be OK to do the speakers on the fosgate amp, and the bazooka bridged on the sony amp. The OHM load is the minimum.

drivelikejehu

thanks! just to be sure... i can use the rockford amp to power the 4 fronts, even though they are 4 ohms each? heres the diagram for the rockford amp when using 4 channel and 4 speakers.

does anyone know the specifications on the sony xm-4045 amp.. i cant find any info on that thing.

AustinCustoms

Yes OHMs is the resistance. 2 is the minimum. Anything over works too.

drivelikejehu

i just made the changes and it sounds GREAT! the rockford amp powering the polks makes a world of difference. thanks for the help!

the only this is i get a whine that sounds like the engine rpms. its super annoying, did i run a wire across somethign i shouldnt have?

AustinCustoms

probably. Make sure your power wires are away from your signal wires. if the have to cross, do it in a "T" (+). If that doesn't work, try a capacitor or a noise supressor. Glad to hear that worked.

matts86fc3s

ive got a panasonic head unit CD/MP3, two 4'' speakers in dash, two tweaters mounted up front and in the rear i have two 500 watt 6x9's in my cargo boxes, and two 5 1/4's in my strut towers all powered by 500 watts and a 10 inch sub behind pass. seat powered by 400 watts.... heres the pic...

http://photobucket.com/albums/c39/mattrx7/

sounds awesome when car is not turned on... my exhuast is soo damn loud and i have no front carpet or padding

drivelikejehu

thanks for the help everyone! i rewired the entire systema nd ran the power cables on the driver side, and the signal cables on the passenger... and the whine is gone!

it sounds great, and gives me a much better feeling now that i know how everything is, and is done correctly.

if anyone wants to buy two unused rockford 12" Stage2 subs, let me know. 100$ each.