Anthony

so i have a alpine cda-7995 mp3/cd head unit and 4 infinity 6.5' speakers. the head unit needs to be amped to work but i was looking into getting a sub soon and i don't really wish to buy another amp. i have a 4 channel eclipse amp which is individually amping each speaker so i was looking for possible options on powering a 12 in sub.

john666

do i even need to say anything..

97teg

If you dont need fading you can hook the left front and rears together to the left front channel and the right front and rears together going to the right front channel. Then bridge the rears toa sub. Hopefully the amp is big enough to run the sub. OR you could just ditch the rears and run the front speakers how they are, unhook the rears and birdge the rears to the sub. The second is what i would do but you loose the rear speakers. Which ever sounds good to you. Again hopefully the amp is big enough to run the sub.

Anthony

don't be such a post whore, either contribute or don't post. this is not off topic, and the fact is if i'm not car audio savy it's because i don't major in car audio like some people.

b00gers

just a quick correction, the HU can work without an external amp. its the speakers that need an amp to work since there is no internal one in the HU. im sure you knew that, but just worded it wrong. h: anyway...

you have a 4 ch amp. you have 4 speakers. and you now want a subwoofer. but you dont want to buy another amp to power the sub.

you can do a couple things...97teg said it...but i'll say it again anyways. h:

1. you might be able to bridge the F and R left together in parallel, and the F and R right together. that way, those 4 speakers will take up 2 channels on the amp. the downside. you will lose that "fading" ability because the whole right side is looked at as "one" speaker and the same for the left.

and by wiring it together in parallel, you are cutting the impedance in half. it just went from a 4OHM load to a 2OHM load. what does this mean? in the simplest terms, you have to make sure that your amp is stable at a 2OHM.

to wire the speakers in parallel, you take the "-" on each of the two woofers and that goes to the "-" on ch1 of the amp. and you take the "+" from the same two woofers, and that goes to the "+" on ch1 of the amp. then you do the same for the other 2 woofers.

2. your other more easier option is to just get rid of the rear speakers. by doing so, you are opening 2 channels on your amp. those two channels can be bridged to accommodate the subwoofer. downside, you lose the rear fill. i have this setup right now, the only downside i really see is that people sitting in the rear complain about only hearing the bass.

if you are going this route, take a look at your amp, and determine what impedance you need your sub to be when you bridge your amp. most likely its 4OHMs. then go from there.

to bridge the last 2 channels on the amp, you simply use the "+" from ch3, and the "-" from ch4.

Anthony

thanks will and 97teg i will most likely go the route of buying another amp and sub.

b00gers

even a better choice :thumbup: