I have an Alpine with 4 pre outs. The rear set can also be set to sub-woofer out via the Head Unit. I have a set of Subs running off of a mono amp, and another 4 channel amp running the rest of the car. My question is: What is the best way to hook this up? I'd like to configure the Sub Out option to go from the rear pre out to the Sub amp, and the front pre out to the "A "side of the 4 channel amp. However, how should I connect the rear speaker out to the "B" side of the 4 channel for the cars rear speakers? The amp has a speaker level in option as well. Should I run the Head Units rear speaker wires the the "B" side of the amp? Hope I've not confused anyone.

I think i understand what your saying. I had to read it a few times but i undestand it now. As for using the speaker level input...you wont get the best sq that way. What is the model number for your Alpine. Mine is a couple years old now and it has front, rear, and sub RCA outputs on the back. for a total of six. As far as i can tell from what you said ur only real option is to just do what u stated. you really dont need to run the four channel at all. The vocals in my firebird are very loud and clear without an amp, and my bass is just amazing. If you really really want to amp your speakers, as far as i can tell, your only option is to do what you said above

I think you know what you think I'm thinking.......I think

Anyway, I explain things better than I can type them. I just got hold of a CDM-7861. Seems like quite a nice deck. I already have two Rockford Fosgate 10" subs powered by a Fosgate 300 watt mono amp. Now in addition to that I'm going to use the 4 channel to power the rest of the car (sail panel and kick panel speakers. So basically I'd have the rear preouts going to the subs amp only. The front preouts going to the 4 channel, leaving only speaker outouts from the deck for the remainder. Just wondering if I'd be stressing the Head Unit out by using preouts and speaker outs?

hey man. using the speaker level input isnt the best idea. just as mtwlkn122 was saying.

what your deck has is 2 pre-outs. front and rear. each of the rca connectors are not counted as one, but as a pair. alpines do have a way to use the rear as a sub out. thats a great, great feature.

my suggestion is to run your front pre's to channel 'a' of your 4-channel, and obviously your rear pre's to your sub amp. now, run to your local car audio store, and ask them for a line converter. you'll want to get one that has adjustable volume. what a line converter does, is take an amplified signal, and converts it to an audio signal. it has 4-5 wires coming up into a little box. that box has another set of rca's. hook this up to the wires on the back of your alpine for the 'rear speakers' (usually the purple-purple/white and green-green/white if i remember correctly) and run the new rca's to your channel 'b' of your 4 channel. this will give you a nice clear sound. and it keeps you the same length of rca's going to your amps. also, as a side note.....make sure you run your amp power on one side of the car, and your signal on the other. this will help with any ground noise.

scosche makes a killer adjustable line converter for around $20.

here is a picture.




hope this helps my friend

Thanks for the help. I actually have a 4 channel line converter that I was going to use on an old Sony. I'll just use 2 channels for the rear speaker outputs. This is still better for signal than running the speaker wires direct to the amp? This amp does have speaker level inputs as an option

yeah man. getting it to those rca pre's is a major deal. you actually get some decent voltage that way. if you use the speaker level inputs, you're just sending amplified signal to the amp, and the the amp converts it. the amp doesnt have quite as good capabilities. on top of that, if you convert the signal right out of the head unit, it has a longer path to clean up.

Sounds good, I'm going to hook it up as you suggested. Once connected to the line converter, will the rear speakers be affected by volume change to the sub? Or will there control be independant of the sub?

Why not just split the front output and send it to the front and rear inputs of your amp?? Since you're using the rear for the sub out, you don't have a fade capability anymore, just adjust the gains on your amp to where you like the front/rear balance and you're set. I've done this on more than one system and it works great, just get a couple of RCA Y adapters to split the front output.

you should have independent control of the sub this way. now, fading...thats a different issue. but thats what the volumes on your amp are for.


also, you can just split it out if you want. the only problem with that, is that you cut the voltage going to each input. the voltage is one part of the quality of sound that comes out.

ie: alpine says that have 5v pre outs....now, they dont actually produce that, but its still a pretty clean signal. the louder your volume is on your reciever, the more voltage will pass through it. so, to do this....say your alpines top volume is 60. test your amp with your reciever volume around....45. so 45 is your normal listening position. the volume you like. if you're amp's gain is low, no big deal. its not usually good for them to be cranked all the way up anyway. this will send good voltage. dont let the speakers distort here though (using the gain on your amp). that way, if you have the tops off, and feel like cranking it up, you still have "15" to move.

eclipse is the only reciever that i have seen that has a perfect 16v signal. and it requires a serparate box. its 8v outa the reciever, and then hits the box, and converts to 16v. 16v is like plugging a microphone into a sound system. its pure voltage. but then again, i've only found one amp that will support a 16v input. so no worries. haha

sorry if that was TMI. just want to get you as much info as possible.!

I wonder if your 4channel amp has a mode selection on it.Then you dont have to worry about splitting signal or y adapters etc.alot of 4 channel amps have a switch on it so that if you only have one input(front rca's) you plug them in channel A and the amp will send sound output to all 4 speakers and all you have to do is adjust and tune the fronts and rears on the amplifier.

You wont have fading ability but atleast you will have sub control and your system will still be at its best ability without signal dropping.I prefer not to use rear speakers anyway.

My orignal system was stout for non amplified,it consisted of a pioneer headunit,alpine type r 6.5 coaxial front speakers in custom kick panels,6x9 woofers..dont recall the brand.The pioneer is able to use rear speaker line as subwoofer and can be bridge and put out a decent amount of power for the 6x9.sounded like a single ten to most ppl.Then i decided to try a single ten in a box running off deck power bridge and it worked even better surprisingly.Ran that for 2 yrs happily as a perfect low budget daily system.