For the Car Stereo guys...

[southtj]

I've had the Jeep for two years now with the factory stereo and have had enough. I rolled all my coins in my change bucket and ordered an Alpine amp and head unit. Now the question is about wiring up the amp. I've installed speakers and stereos before but never an amp. Any advice or tips? In the amp description it says this:

Drive your front and rear speakers in 4-channel mode, or switch to 2-channel mode to power a couple of small subs. Want the best of both worlds? Use channels 1 and 2 to power full-range speakers, and bridge channels 3 and 4 to power a sub.

What should I do? I have already replaced the stock speakers with Boston Acoustics and still have the factory sub. How should I hook this up and still use the factory sub? Anyone know what size the factory sub? I couln't find any info about replacing the sub and I'd rather not add a box since space is at a premium.

 

[dingus]

I think the stock sub is 8", not positive tho

 

[TwistedCU]

Use the front channels in parallel to the four full range BA speakers, then bridge the rear channels to your sub. If it is in fact an 8" sub and you don't like how it sounds, Boston Acoustics used to make a great 8" sub, I imagine they still do. Whether or not it'll fit in the stock location or not I can't help ya sorry.

The only drawback to this would be losing your fader between the f&r full range speakers.

Does the amp have a built in crossover for the sub?

 

[yjdave]

If the amp is any good.....Run the amp in 4 ch going to all 4 speakers f/r..Then go and bridge ch 3/4 and run stereo and mono at the same time. This will allow you to fade front to rear and balance left to right with the sub staying on the rear channel and no balance.(not need w/subs)....This will however drop the ohm load on the rear ch.(maybe a problem if the amp cant handle dropping down to about 2ohm.

 

[LGR]

Also, as far as amp wiring goes..I'd run the battery cables on one side of the jeep and the cables to the head unit on the other. Try to keep them away from each other, you might get some distortion if you run them right next to each other.

 

[southtj]

Here are some specs on the amp.

Details:
» 4-channel car amplifier
» 40 watts RMS x 4 at 4 ohms (50 watts RMS x 4 at 2 ohms)
» 100 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)
» 2-, 3-, or 4-channel output
» variable high-pass/low-pass filters (50-400 Hz, 12 dB/octave)
» tuned Bass EQ (12 dB bass boost at 50 Hz for channels 3 & 4)
» subsonic filter (15 Hz, 24 dB/octave for channels 3 & 4)
» Tri-way capable (Tri-Way Crossover required)
» MOSFET power supply
» CEA-2006 compliant
» STAR Topology (minimizes internal noise and prevents ground interference)
» speaker- and preamp-level inputs
» preamp outputs
» gold-plated screw terminals
» fuse rating: 15A x 2
» 10-gauge power and ground leads recommended — wiring and hardware not included with amplifier
» 11-1/4"W x 2-3/8"H x 9-9/16"D

TC, as far as the crossover, I'm not sure. More info about it here. http://www.crutchfield.com/S-bwRU9X...?g=120&id=features_and_specs&i=500MRPF250#Tab

YJDave, do you think this one is good enough.

LGR, I had heard that before but forgotten, thanks.

 

[yjdave]

442,,I would feel good useing that one for a 4 ch...You are running 4 speakers plus a sub, right? If so you either need another amp for the sub or you need to raise to ohm load to the amp by useing 8ohm speakers for the rear and kinda trick the amp into thinking it's not droping below 4ohm....There are so many variables it hard to say for sure w/o knowing everything you have and want to do.

 

[southtj]

4 speakers and the sub, correct. Is there a way to use the power from the head unit to power the sub and use the amp for the 4 speakers?

 

[yjdave]

Ya i suppose you could run the front speakers off the deck and use ch 1-2 for the rear speakers and use ch 3-4 bridged to the sub..That might be your best bet to use everything you have, just take a little tweeking to balance everything out. Plus you can use the xover in the amp for the sub.

 

[southtj]

Ok, I've installed the head unit with no problem and had started on the amp before I had to stop for the day. Before I get started again tomorrow, can someone please tell me where the wires to the rear spearkers run. I've looked under the carpet all around where the roll bar meets the floor but no sign of them. Where can I tap into those rear wires?

 

[dingus]

at the head unit.

 

[southtj]

at the head unit.

Well, I didn't want to have to run the wires all the way to the front if I could tap in where they run up to the sound bar. But I did think of that as a last resort.

 

[JeepMonkey]

I think the wires for the rear speakers run along the floor/door inside of a bundle that also includes the wires for the rear defroster/wipers. Mine split off right at the vertical roll bar behind my seat and go up to the sound bar.

 

[southtj]

I found them there jumppr but they were wrapped up so tight it was just as easy to run them all straight up under the center console to behind the dash just like dingus said.

I hooked the amp up to the four speakers and ignored the sub for now. For some reason, ever since I replaced the factory speakers last year, it doesn't seem like the sub is even working. So now I have a nice stereo, a good amp and 4 dinky speakers. Sounds better but not great yet. Next up is a sub and another amp. I've found a 6.5" sub and an alpine amp that will run me about $230 for the both of them. As soon as I find that laying around the house I'll do it. Hmmm.....I could just use the credit card.....thinking.