I have a HU that only has two sets or RCA amp preouts. One set is currently going to a 2 channel amp that I have hooked up to a 10" I have another 4 channel amp that I want to connect to the door speakers. Is there a way to hook everything up with only 2 sets of amp preouts? I want to still be able to control front/rear and left/right with the HU. Can you use the wires that go from the HU to the stock speakers and route these wires from HU to amp and then to door speakers? I dont know a ton about this stuff so any help would be greatly appreciated. Also, I am replacing the door speakers and will have 45w RMS going to each one. Any suggestions for something that will sound good? Components vs 2 way vs 3 way? Trying to not to spend too much so any good deals that are out there right now would be helpful too. Thanks a lot!!!

 

You can hook up two amps with two sets of RCA's. The RCA pre-outs should be labeled "front" & "rear." Hook the front RCA's to the speaker amp and the rear RCA's to the sub amp. I don't think you will be able to control the front & rear speakers with a two channel amp....

This won't work...the only input the amp receives from the HU is the signal, via RCA cables.

 

Thanks,

Well I have a 4 channel amp I was going to put on all the door speakers which should allow me to control front/rear, left/right. I just didnt know about the RCA hook ups. I dont suppose there is a way to split an RCA so the signal could be sent to two locations (speaker amp and sub amp)???

 

No, you can't split the RCA cable from the speaker amp to the sub amp...but most amps have a RCA output that allows you to run a RCA cable from the speaker amp to the sub amp. It has the same principal, but without a splitter...make sense?

 

You can get single male to double female splitters from just about any place that sells home or car audio. But you will only have to do this if none of your amps have the pass through like 2trucks is talking about. If you choose to use a splitters either at the HU or where the amps mount you could even install a 15Kohm potentiometer into the line going to the sub amp to give you a variable sub level control. Better yet you could get a decent pre-amp or EQ in half din size that would give you even greater system control as well as sub level front rear fader control. You have alot of options actually. Just depends on how you wanna go about it. The EQ is a nice touch to really dial in your sound just like you want it. I see really nice used EQ's selling on ebay for 50-150 bucks so if you think about it that way it would really be a very small investment and yield excellent system flexibility.

 

Question about the potentiometer.

You said to mount it between the speaker amp and the sub amp. So your taling about putting it in series with the RCA cable? Will this basically just be a volume adjustment for the sub? If this is the case it will only let you decrease the level going to the sub amp correct? If you could maybe explain the benefit to this a little better I would really appreciate it!

Thanks!!! Its really nice to have a resource like this when you dont have all the answers...

 

Yes, the potentiometer will control the level of the sub amp by changing the impedance on the RCA output stage of the HU. Just as a 4 ohm load creates more power from an amp than an 8 ohm load. I know that is not as scientific as some may like it to be but I try to keep everything on a level that everyone can understand.

Yes, You would wire it in series with the RCA cable (center conductor) I suggest using a dual pole potentiometer so that you can control both left and right signal equally without variance in signal level (or resistance).

By the way. In regards to your previous post I assumed you want to split the RCA cables prior to your mid/high amp. So, therefore I would suggest that you use the single male to double female RCA adapters (splitters) at the HU on the rear RCA outputs and use them to drive both sub amp and rear speaker amp (ch 3&4).
This way you can mount the sub control pot up in the dash somewhere. Or, like I said previously. I think your greatest benefit would be to add the preamp or EQ to the system. By the time you pay for the RCA splitters and the potentiometer you will probably be around $20 provided you can solder and have what you need to make the mod. For $30-40 more you could just add in the EQ or Preamp and get additional benefits.

 

Oh, the benefit of the potentiometer would be only that it allows you to control the sub volume level independently from your front and rear speakers.

 

Actually, you can do that. Those are also know as "high-level inputs" if I am not mistaken. Some of the older amps had both high and low level inputs, high being speaker wire inputs and low being RCA's. If your amp did not have these, Wal-Mart sells a converter for about 15 bucks that takes your speaker wire inputs and runs them through this little black box which has your RCA's on the other side
This little device is actually used for people that want to use their stock radio but want to add an amp.

 

I never said he couldn't use high level inputs. His question was...

 

The answer to this question is yes. Maybe there is just some confusion, I'm not trying to be a butt or anything.

 

Since you say it can be done, please explain to me how you can install an aftermarket amp using ONLY factory wiring.

 

He did not mention using only the stock wiring. You have to run speaker from the HU's speaker out to where ever the amp is located. Then use the line converter to convert the speaker wire to RCA's.

Ok, I see where he says use the stock wiring, but why in the world would you want to use that little bitty stuff. Especially if you are wanting to run them through an amp. Unless the amp is like 20x4 that little stock wiring would probably get hot and become a fire hazard.

 

Actually, the factory speaker wiring is heavy enough to handle more than 100 watts RMS with room to spare.

If I am not mistaken, the factory wiring is #16 AWG. That is plenty capable of handling your average load presented by a door speaker / amp combination.

 

I agree with B-MAN on that one. Check your wire gauge charts to actually see what the amperage/wattage capability of the wire is on the stock speakers. Keep in mind you must use wire length also as a factor in your determination.