[joeyv123]

I've been searching some older posts but haven't quite found answers to some questions I have about the "stock" 4 speaker stereo.

The stereo sounds ok, though, as I've read it may be worthwhile to replace the speakers. I turn down the fronts and run most of the audio thru the rear speakers. I like how the sound resonates through the cabin from the rear. However the volume isn't quite there, and it gets a bit muddy when it's pegged. What I'd like to do is add a 4 channel power amp, bridging two channels for a sub and running the other two channels to the rear speakers.

What would be the most cost effective way of doing this? How do I avoid amplifing electrical system noise? Also, how do you control power to the amp? I don't want to drain the battery by not having a way of turning off the power amp.

 

[Robo]

There are many opinions on what audio brands and wattage's work best for particular applications; this is just basic info and comes from first-hand experience over the years.

For the OP question ----- no remote turn-on wire with standard factory head unit:

For turning on/off the amp look at the rear fuse box (trunk) (Fuse #9, 20 Amp Yellow, Usage = Cigarette Outlet). Just need to purchase a standard fuse tap and this will turn on the amp whenever the ignition key is on.

There's many ways of adding amplification to the base 4-speaker stereo.
Here's the low/high cost of doing it:

Low cost system 4-channel amp
channels 1&2 = 50 watts rms
channels 3&4 Bridged = 150 watts rms -
nice SQ and mild SP:

1. Modest 4-channel amp (example: 600 total amps and 4-Ohm configuration)
2. Two 6.5" 3-way rear speakers that handle 50-60 rms watts ea.
3. 10" vented sub 4-ohm 250-300 watts rms/set at 40Hz range - nice bottom end thump so the lights don't totally dim all the time


High cost system 4-channel amp
channels 1&2 = 75+ watts rms
channels 3&4 Bridged = 400+ watts rms -
loud SQ and intense SP:

1. High dollar 4-channel amp (example: 1000+ total amps and 2-Ohm configuration)
2. Two 6.5" 3-way rear speakers that handle 75-80 rms watts ea.
3. 12" vented sub 2-ohm 500-600 watts rms/set at 30Hz range - extreme bottom end thump and the lights totally dim.

Connecting it all - Using Base 4-speaker Head Unit

1. Tap into rear speakers for line-level inputs (amp w/very low .01% THD or use line-level to RCA converter if no other option)
2. Run 6.5" speakers off amp channels 1&2
3. Run 10"/12" sub Bridged off amp channels 3&4
4. Leave 6x9"s connected to head unit

Professional Installation
The flip side is most stereo shops like to install decent/high power 2-way 6x9"s in doors and 2-way 3.5"s in the dash and run them off 4-channel amp by either front/rear line-levels or RCA converters. The rear 6.5"s would stay connected to the head unit and be used only as FILL. Most people like the sound stage up front instead of coming from the rear.

 

[SouthBayRay]

wow, what a great write up, Robo! thanks for taking the time to do this.

 

[joeyv123]

Thanks that definately helps. Any opinions on the amps listed below?

Alpine MRP-F300

Kenwood KAC-8405

Kicker 10ZX350.4

Rockford Fosgate Prime R300-4

Infinity Reference 475a