2004 JBL Synthesis Amp Replacement

[kscott]

Before you bite my head off, I have searched through these forums for quite a while, but still have this question.

I have a 2004 Sport with the 10-speaker JBL system.

I am replacing the factory HU with a custom-built PC (details here: http://www.mp3car.com/vbulletin/showthread.php?t=36104)

Coming out of the PC will be standard stereo RCA jacks. I would LOVE to just use the amp that is currently in the system, but after reading and experimenting, I have come to grips with the fact that it won't happen.

So, I'm amp shopping, but I'm new to car audio. Here are my requirements:
Must take RCA inputs
Must power ALL current speakers (including center front and sub)
Must sound only AS GOOD AS my current system (I've already spent enough $$)
Must be able to be mounted where the current amp is so I can use the current speaker wires.

I'm really looking to do something inexpensive here, so what should I be looking for? Any recommendations would be greatly appreciated (my local stereo shop tried to sell me a $600 amp yesterday).

Thanks in advance.

 

[rando]

It depends on how you want to hook it up. Do you want 4 channels + center + sub? (i.e. six amplfied channels) or can you forgo front/back fading? Looking at your setup, it looks like you plan to use the built-in sound car on your motherboard. Does it provide a seperate sub output or would you be more satisfied pulling the base out of your left/right channels (external to the computer)?

Sorry for so many questions, but the possibilties are fairly large though they might get narrowed significantly based on your budget and space constraints.

 

[Cliff s]

To do some shopping do a Google search, it will give some ideas what's on the market.

All the speaker wires terminate at the stock amp. My suggestion is to use 2 or 3 of
the equalizer amps, some have 200 watts. These are fairly inexpensive and you can
equalize the speakers seperately. The front two on one amp the rear doors on another
and the sub and rear post ones on another. These amps are small and with a custom
bracket fit where the stock amp is. If you can be satisified with permanent settings
and don't like to diddle, this should work. Equalize the whole system to where you
like it and enjoy.

I am still trying to decide what to do with mine.

Cliff s

 

[kscott]

i can definitely forgo front/back fading for now if there is a substantial cost savings (which i think there is). and yes, i'd like to pull bass out of the L/R channels from the sound card (onboard M2 10K).

in fact, for now i wouldn't mind losing the two tweeters in the cargo area either. so i guess that leaves me with left-front door, right-front door, left-rear door, right-rear door, center dash, and sub.

dont really know what i'd want to do about the center dash speaker. either dont use it, have it be a mono blend of L/R, make it L or R, or have it be a true center channel. i dont think i really care... whats the cheap option?

thanks for the help.

 

[kscott]

cliff -

these equalizer/amps... i've never seen them before. it looks like they're basically just equalizers that amplify the audio a little bit on the output. doesn't seem like they're actually made to do amplification, but they might work.

is that an accurate reading of what they are?

i'll definitely keep that open as an option.

thanks..

 

[rando]

So maybe you can get away with a standard 4 channel amp them. Use two channels for your left/right (front and rear in parallel -- assuming your amp can do it). You can either ditch the center channel and bridge the remaining two channels to drive your sub or use 1 channel for the center and 1 for the sub. Alternatively, you can buy a few (potententially smaller footprint) 2 channel or mono amplifiers.

I'm not sure if the factory tweeters in the far back have built in crossovers or if that part was in the factory amp. If the crossovers are in there, you can probably just run those in parallel with the rest of your left/right channels.

 

[Cliff s]

Here is a link to one brand, Pyramid

www.pyramidcaraudio.com

Maybe a model 808, there is also a place to download the manuals on the site.

These are widely discounted and rather inexpensive. The purests will scoff at them, but they should work OK.

Cliff s

 

[FlyingDutchMan]

I'm not sure if the factory tweeters in the far back have built in crossovers or if that part was in the factory amp. If the crossovers are in there, you can probably just run those in parallel with the rest of your left/right channels.

Rando...from the wiring diagrams is doesn't look like tweeters in the far back are wired for stereo, or is that just me reading he diamgram wrong? Both are wired to the amp to the same single channel it looks like?

 

[kscott]

i read that the same way. which means that the crossovers are probably built into the amp and it feeds a mixed L-R audio to the tweeters... i guess.

 

[rando]

I hadn't looked at the diagrams ... but yah, it appears the two rearmost tweaters run off a mono channel. The diagram also shows a series capacitor (i.e. highpass filter) embedded in the speaker (same for the front tweaters). If you want to run them L/R, it looks like you can pick up the wiring for each speaker at J42 or use the S23 (OEM amp connector) for the R and IE1 (A2, A4) for the L -- you'll have to pull some pins or cut wires.