i have a MB Quart dsc4125 4 channel amp that i want to bridge down to 2 channels to run my ID XS65 components. off my head unit i have 2 sets of rca, one set for the "Front" and one set for the "rear"

my question is how do i get the signal to be stereo and not mono? i hooked up the rca's like i normally would.. i put the "front" rca's on channels 1 + 2 and the "rear" rca's on channels 3+4, i switched my amp to 2 channel mode, turned it on and the signal was mono (i could tell because i used a song that usually has the left speaker playing in the beginning, but both were playing)

how do i plug in my rca's to make the signal stereo again while still being bridged?

The reason it's not working is because you have both speakers playing both left and right signals.

You will need to purchase a pair of y-splitters. Connect them to the end of the RCA's at the amplifier end of the cable. Let's say you have the left speaker on channels 1&2 and the right speakers on channels 3&4. You would then plug the y-splitter for the left signal cable into the inputs for channels 1&2 and the y-splitter for the right signal into the inputs for channels 3&4.

so i would only need one set of rca's going from the headunit back to the amplifier then? so i will have a left and a right rca, i put a y adapter on the left one and put it on channels 1+2, then put a y adapter on the right one and put it on channels 3+4?

so i need 2 of these http://www.knukonceptz.com/productDetail.cfm?prodID=KLA-1F2M-BK

one attached to the left channel of a rca and the other attached to the right channel of a rca, with only one rca cable ran from the head unit to the amp?

Edited April 26, 201213 yr by curt96olds

If i'm not mistaken you turn the switch to mono and the run the rca's to 1-3 or 2-4 for stereo bridged but you might want to check your manual.

EDIT: Switch it to 2ch and run the rca's from 1-3 or 2-4. They more than likely sum both channels in mono for front and rears so it may not make a difference which pairs you use.

Edited April 26, 201213 yr by Skullz

To run that comp. set while utilizing the full use of that 4 channel amp to do so, is to hook it up into stereo bridge.

Place switch into 4 channel position.

rca from head unit -------------------- amp

front right ------------------------------ rear left

front left ------------------------------ front left

rear right ------------------------------ rear right

rear left ------------------------------ front right

turn off filter on head unit (if it has one) and set amp x-over switch to full or all pass for both front and rear channels on the amp

Edited April 26, 201213 yr by StreetLegal

Put the switch to 2ch and plug in your RCA in 1&2.

Put the switch to 2ch and plug in your RCA in 1&2.

i tried that, and it still played in mono... im not sure what im doing wrong.

i have 3 sets of rca ran in my car right now,

the "front set" hooked to the front outputs on the headunit

the "rear set" hooked to the rear outputs on the headunit

and the rca ran for the subs, which is out of the equation as far as this problem goes

the combinations ive tried are

rca's hooked up like normal, meaning the front outputs on h/u to the front inputs on amp, and rear outputs on h/u to the rear inputs of the amp

then i tried to totally disreguard my "rear set" of rca and just run the front set to channels 1+2 on the amp while it was in 2 channel mode and i still got mono

so i would only need one set of rca's going from the headunit back to the amplifier then? so i will have a left and a right rca, i put a y adapter on the left one and put it on channels 1+2, then put a y adapter on the right one and put it on channels 3+4?

so i need 2 of these http://www.knukoncep...dID=KLA-1F2M-BK

one attached to the left channel of a rca and the other attached to the right channel of a rca, with only one rca cable ran from the head unit to the amp?

Yes, only 1 RCA cable from headunit and using the y-splitter to send only the left signal to both inputs for 1&2 and only the right signal to both inputs for channels 3&4.

If i'm not mistaken you turn the switch to mono and the run the rca's to 1-3 or 2-4 for stereo bridged but you might want to check your manual.

EDIT: Switch it to 2ch and run the rca's from 1-3 or 2-4. They more than likely sum both channels in mono for front and rears so it may not make a difference which pairs you use.

I couldn't tell from the manual what that switch does. Which is why I suggested the y-splitters. I couldn't find in the manual an example where that switch was set to 2-channel or an explanation of what the switch does.

I was afraid in 2-channel mode it would simply route the input from channels 1 & 2 to the inputs for channels 3 & 4 so that you could use only 1 RCA cable to supply input signal to all 4 channels. In which case, it wouldn't work for bridging.

To run that comp. set while utilizing the full use of that 4 channel amp to do so, is to hook it up into stereo bridge.

Place switch into 4 channel position.

rca from head unit -------------------- amp

front right ------------------------------ rear left

front left ------------------------------ front left

rear right ------------------------------ rear right

rear left ------------------------------ front right

turn off filter on head unit (if it has one) and set amp x-over switch to full or all pass for both front and rear channels on the amp

1) That would unnecessarily require 2 runs of RCA cables from the headunit to the amplifier with zero benefit.

2) He needs to highpass the speakers, either with the headunit or at the amp. He shouldn't have the both set to full range.

Put the switch to 2ch and plug in your RCA in 1&2.

I couldn't tell from the manual what that switch actually does? If it simply duplicates the inputs from ch 1&2 to ch 3&4 then it wouldn't work.

thanks Impious, you cleared up all of my questions, and even though the other suggestion sounds like it could work since i already have the second set of rca's ran.. im gonna go with the rca splitters, that way seems the easiest, i just hope it works, running it through my head it sounds right, so we'll see lol

thought he would be using the passive crossovers from the component set.

thought he would be using the passive crossovers from the component set.

I presume he is as well. Passive crossovers only lowpass the midbass.....it's not a bandpass filter on the mid, the passives don't highpass it also. That needs to be done actively, either in the HU or in the amp.

thought he would be using the passive crossovers from the component set.

I presume he is as well. Passive crossovers only lowpass the midbass.....it's not a bandpass filter on the mid, the passives don't highpass it also. That needs to be done actively, either in the HU or in the amp.

I run my 4 ch amp in bridged mode to one set of speakers in the front. I did not use any y-splitter, but I already had 2 sets of rca ready.

I don't remember exactly how my installer set it up, but I do know he had to reverse something ! Like Street Legal said, I think so.

Good luck !

yeah im using the passive crossovers that come with the speakers, i have the HPF on my headunit set to 80hz