mikeyboy2011

Hi All,

so after upgrading all my speakers, and doing my amp setup for the rears/sub, I'm seeing that I just need more volume/power up front to balance the system out...

The stock amp location is just spacious enough to fit even the smallest 4 channel amp I can find....

So my question is:

Has anyone installed an AMP up front somewhere behind or near the glovebox?? Is there room back there?

Or is it easier to just install under the passenger seat?? not sure how much clearance there is under the seat??

Trunk Monkey

iTrader: (1)

You can easily get an amp under the seat. There are a few solid, small amps that will drive speakers cleanly. Look at Alpine PDX's, Arc Audio

My first thought though, is why are you amp'ing the rears? Just take those 2 channels to the fronts and let the stock amp handle the rears. Fronts are WAY more important

mikeyboy2011

cool, I figured I could fit a small amp under there, just wanted to see if someone already did it!

Well, I'm quite picky when it comes to sound in my car, I like to really crank it sometimes, and also like crisp highs, and solid bass...the max power from this amp just wasn't cutting it.

I put Boston Acoustics ProSE 60s in the rear, along with a second 8" sub (that I already had from my previous car) that is in a standalone enclosure, so it just made sense to amp the BA pro60s, along with the 8" sub..

I think I read on here that someone tested the sound spectrum out of this head unit, and there is quite a significant drop-down around 1khz I think they said??

so once I do all this, I have a feeling I will end up placing some brand of processor in the mix to bring the high ends up the spectrum back up...

jda123

Maybe -3db around 1000hz, is what the post said. Very usable. Still, if you want high end sound, then you need to process.

If you get a PDX, then make sure it is a newer one or you will get a lot of noise and distortion. People are selling the older ones for cheap, so be careful.

JL XD should fit too. Just don't get it too tight or they will overheat - there needs to be air around it.

mikeyboy2011

Just to update, I finished my install, and it sounds outstanding!!

I put a JLAudio XD400/4 under the passenger seat, fits easily, plenty of space for air flow...and I put a JL Audio HD600/4 in the trunk...

I set it up as follows:

1) removed the stock amp completely, makes it so much cleaner in that kick panel for wiring up RCAs,etc with that amp out of the way.

2) ran the pre-outs (balanced/diff. signals) from the 20p connector (signals from audio unit) for Front L/R/Center, and Sub to the spot under the seat, for the XD400 amp. Speaker connections for these speakers were also extended to under the seat.

3) Ran the pre-outs from the 20p connector to the trunk area for the HD600/4 amp, for the Rear L/R, and Sub. (put a y-splitter in the kick panel so I could send the sub signal to both amps, which I explain below)

The XD/400 under the pass. seat powers the front tweets, center speaker, door speakers, and the rear deck (stock) 8" sub. (ie channels 1-2 are front tweets/doors, channel 3 is center, channel 4 is stock sub)...

All front speakers were replaced with Infinity speakers, Infinity Kappa 10.9t's for the tweets, Infinity 3032cf for center, and 63.9i's for the doors.

The HD600/4 in the trunk is for the rear 6.5s (Boston Acoustic ProSE 60s), channels 1-2.

Channel 3 is for my standalone 8" DVC sub (coils in parallel for 2ohm impedance)...it's in a standalone enclosure.

channel 4 is unused (could instead be used for the stock sub if I decide the 75w from the front amp is not enough)

So right now I have the stock sub powered from the front amp, which seems WAY more than enough, plus I'm not sure of the max power handling of this stock sub anyhow, I doubt it's anything more than 100W, if even it's rated that high?

There is absolutely ZERO noise in the setup, as I stated, those headunit "pre-outs" from the audio-unit are indeed 100% balanced/differential signals. These JL Audio amps have balanced/differential inputs, so all of the induced engine/electrical noise on the signals is eliminated.

The signal strengths are absolutely fine, I have the signal-levels for each amp set at about the normal/mid point settings for each amp, and the volume is quite loud at only 10 on the head unit.

Plenty of room for even more gain, and for most this is probably even too much volume at 10, and there is no clipping going on, so it's no where near over-gain on the inputs.

sound clarity is astounding, from what I've tested so far, with the two 8" subs, as you all stated, the bass hits real hard, what a difference this power has made, for both the fronts and rears. I never heard that stock sub hit so hard. The crisp highs now through those tweets and doors is awesome.

Best upgrade so far I have ever done, I did a similar setup in my car before this one (a Mazda Millenia), but it did not come close to this sound. One thing that is nice is the custom level controls in the head unit for things like center and sub, so that I can turn down the level on the center speaker quite a bit, and turn up the sub quite a bit, (since in the front amp I can't control gain for each channel individually)

If I get a chance this week, I'll post some pics of the amps installed, and how it looks inside the kick panel without the amp, and the connections out..


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One thing to note, in case it helps anyone that has been frustrated with the remote turn-on wires, those signals in most cars/head units are not designed to drive much current, so you usually can't daisy chain too many devices off of them without the signal dropping voltage too much.

I normally take the remote turn-on wire at the best location (in this case in the kick panel), and use it to turn on a small/microsized relay...microrelay I used only requires 20mA to drive the relay coil...
(can get a micro 12v relay at radioshack, they have plenty of options)...

Use the relay to feed a new 12V source to wherever you need...this will be your new remote turn on wire, and you are really only limited by the current handling of the relay contacts (and the wire you are using)....so in otherwords, the original remote-turn on wire is now just turning on/off this relay whenever the remote turn on wire activates....

the relay I used was rated at 1 amp for the contacts (no where near the little current needed to drive the remote-turn ons for two amps)..

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