New amp

I just got a JBL PX300.4 4-channel amp this weekend. I'm going to be hooking it up to my front and rear speakers of course. I currently have an Infinity amp hooked up to my headunit that's powering my "10 sub. My H/U is an Alpine CDM-7874 wich has 2 perouts on the back of it. The ones my sub amp are hooked to right now are used as either rear channel preouts, but also have special functionality for when a sub is hooked to them, so that's how it's setup as right now. Since I plan on keeping the sub hooked to them, the other set of preouts I'm planning to hook to the JBL 4-channel amp for my rear speakers, and then my fronts I'll hook up via a line level input/output to the amp. How would I go about running the wire from the fronts to the line level converter box I have, and should I mount that box in the trunk close to the amp, or somewhere under the dash closer to the front speakers? I want to keep the sub hooked to the H/U since it controls the volume of it independant from the other speakers, and hooking the sub with a line level, then I can't control it independantly like I can right now. Or is there some sort of RCA splitter I can get that will allow me to hook BOTH the front and rear channels of the amp, to the one set of preouts on the back of my H/U? :confused:

Thanks for any help.

i am pretty sure that there is rca splitters that convert two cables into four. someone told me about them on here before. i would also say to mount your converter box back by the amp.

Coo, thanks.

Would I get much signal loss using a splitter like that? Though now that I think about it, I won't have adjustability of the fader if I go this route, ugh! This is frustrating. I guess I'll just have to go line level inputs for the front channels and have the rears to the RCA preouts. :bloated:

what are line level inputs?

i got an idea. what if u get two of the rca splitters, i believe they are called y cables and put it on the rear channels. hook up rca jacks to the splitters, one pair going to the four channel jbl rear, the other to the alpine for the subs, and regular rca's from the h/u to the alpine's front channels. all ur doing now is sharing the rear h/u outputs and no it won't affect sound quality, but in case ur still worried about it, get the good wires such as monster cables. this application can be use if the amps are far from each other.

if the amps are both in the same area such as the trunk then this can be a simpler method. run rca's from the h/u's front and rear to the amps destination and there u can use a y cable whether from the front or the rear to separate amps. this can make it alot easier and at the same time u save a couple bucks by buying only 2 long rca jacks whereas of 3 in the other application. -warning- make sure if u are going to use the second apllication that the y cables are of good distance, lets say 1.5 to 3 ft if available so u have enough wire reach, or buy a 1.5 ft to 3 ft rca jacks if the y cables don't go the long.

as far as which channel to use for the subs i would have to say use the front if ur trying to create that sound stage effect where the concert (music) is in front. u might already know this, but to get this effect the gains should be more for the front and less for the rear using the h/u fader, so if u have a low rear gain output, this too will effect the subs causing it to have less bass. just a suggestion. although now u can still adjust your subs this too will effect your front or rear interior speakers a little bit unless theres a crossover on the jbl to get rid of the lo's programmed from the h/u for the subs. hope this helps.

makes me kinda glad i got this orion amp which i mention in another thread where i can get six channels from one single four channel amp. this can give me 4x100watts rms to the interior and at the same time bridge the front and rear of the same 4x100 output to get 2x400 rms for the subs. but in my setup, all i need is just one channel bridge to the sub although it needs a filter to drain out the mids and highs, but still it got the job done with a lot less money and work :icon16:

line level inputs are the RCA's, as opposed to speaker level.

A LONG time ago, I had a line level fader - one RCA pair in, two RCA pair out