Hello all,
Was wondering if anybody could answer a question since I'm not real familiar with the wiring part of amplifiers. I still have the stock HU for my EX & am trying to upgrade the sound in my 'E. I'm a bit light on the green at the moment after buying the JL components for the front & Polks for the back. However, I expect that I'm going to need an amp to power the JL's to make them sound decent as the stock amp probably won't have enough power to do the job. I've got my eye on some used amps on ebay to do the job, but what I don't know about is the wiring.

Will the stock head unit allow the use of 2 amps (1 new one & the stock one.....for now) or will it be necessary to get a new head unit to do this. I'll probably get a new HU eventually, but I'm trying to figure out how to make due until I get over the hump financially.

Don't need a full explanation since I'm not going to do the work myself, but I'd like to know if it's possible before I sink the money into an amp.

Thanks for any help you can give me on this......

Being that I've had some audio work done on some of my previous cars, I personally wouldn't even bother with trying to get the stock HU to run a different amp. I've always thought it best to start with a new deck then work my way back through the audio system, ie. the highs, then mids, to the subs. This way you know exactly what kind of sound your headed for depending on the upper sound range components. Plus, the HU will usually be the single most expensive piece of the puzzle. And a lot of the time, factory amps aren't really universal in the area of powering aftermarket speakers that weren't specifically designed for the output of this particular amp.

As for right now, I'd just wire in the low wattage stuff and wait a couple paychecks until you can afford the HU. Save yourself the hassle of tearing into the dash multiple times and possibly goofin' up the wiring and not having any music at all.

It's possible. Better to wire the "line level" preamp outs directly from the back of the HU to the new amp. I put quotes around line level because I am not sure how much voltage the HU puts out. If it is too low (have your installer make this call) you will need to use a Line Output Converter (LOC); it will convert the speaker level signal from the stock amp to a preamp level signal. This is slightly less desirable, as it will introduce a small amount of distortion.

Thanks Nanook!!!

It sounds like what you indicate removes all input to the stock amp & reroutes all the power to the new amp. I'm looking at a couple different options and not all options have enough channels to power everything.

One of the options is a 5 channel that would hook up everything to 45W RMS + 100W RMS for the stock sub. I had wondered with this setup if I would be able to bridge to 90W RMS for each component pair in the front & leave the 92db Polks I just installed in the backdoor on stock amp power since they'll just be for backfill anyway......

The other potential option would be 4 channel that would power all the doors but leave the sub on the stock amp.

Will what you describe leave out the stock amp altogether as I believe you are saying & limit me to where I will need a 5 channel amp??? :?

Please let me know.
Thanks,

Sorry, I didn't mention what I had in mind was powering only the fronts with the new amp. I would leave the rears on the stock amp, as you mentioned correctly, they would be for rear fill only.

I don't know about the stock sub. I think from eMass' posts it gets around 75W RMS from the stock amp, so I reckon 100W from your new amp would help it a bit, but that is only conjecture. I worry if you amp the speakers and leave the sub on the stock amp that the sub won't be able to keep up.

The thing about 5 Ch. amps. is they are large, so you are limited in placement options. Actually, my Soundstream 2 Ch. amp is too big to go under either of the front seats, so it is under the rear passenger side.

Nanook,
In FAQ #14, Emass indicated that the stock amp gives 70W peak or approx 40W RMS to the sub, so the jump to 100W should make a fairly audible difference. I don't know how DVC vs SVC on the amp hookup would affect the wattage that the sub actually sees.

However, you did hit on one item that I glossed over in my thought process which is the size of the amp. I had it in the back of my mind, but I hadn't really taken any measurements until I read your last post. After I took measurements, I have no clue where I would even begin to put the amp I was looking at as it sure won't fit under the front seat....... :oops:

Which Soundstream amp are you using? The one I was looking at was a Soundstream & I've always heard good things & great sounds from their products. Was the fit problem length or height? Also, I assume that when you say you mounted it under the seat that you mean to the floor under the seat rather than to the seat bottom itself. I was looking at underseat mount (on seat) & it doesn't seem to be rigid enough without a lot of special bracket work. Seems like it would be an interesting way to address the problem though since enough slack wire could be run to allow it to still be folded up & still use the whole cargo area......

Back to the drawing board, I guess.... :(

Sub: Hmmm. I wonder about its ability to handle that much more wattage. No idea, but I do wonder.

Amp: I have a Soundstream Rubicon RUB500-2. I am still dialing in the system, so can't give it a final OK just yet, but so far, so good. I think it was a tad too wide and tall to go under the front seat. It's mounted to the floor under the back seat. Neat idea mounting it to the underside of the seat, but removing the seat would be a pain. ;) It was a compromise mounting it there, but it can certainly take stuff placed on top, so it's not a total loss...

Thanks for all the feedback Nanook!!!

I changed gears last night in my amp search & decided to go 2 channel. Found a good deal on an MTX-T8302 that puts out 75W x 2 RMS. Should be enough to take care of my immediate needs. I'm not really a bass thumper anyway - just like to be able to get enough clean sound to hear well on the highway with the windows open. It looks like it should fit under the passenger seat based on the dimensions. I guess I'll find out when it gets here...... :) I believe your Rubicon would be quite a bit larger than what I bought.....

I guess I never thought about removing the seat. I have an old beater truck that I use when I really need to haul larger items so I never intended to do any more than fold them up out of the way. At least that way the whole cargo area would be usable. Necessity is the mother of invention, eh? :wink:

Yeah, I was wondering if the sub would handle the extra wattage too. After inspection, it did appear to be somewhat better than the other stock speakers. Guess I'll leave it be for now......

Thanks again!

Any time. ;) I am a poor substitute for our resident mobile audio guru, eMass.

Haven't seen him around lately. eMass, where you at?

I'm always watching!

My recommendation would be to go with a couple of 2 channel amps - 1 under each seat. Run the front speakers off one amp, run the sub(s) off the other amp, and run the back speakers off of the head unit power. This strategy of course assumes you buy a head unit and bypass the stock amp completely.

2 channel amps almost always fit nicely under seats and the physical separation of the 2 amps keeps large bass notes from drawing power away from the other speakers - this can be the case with a single 4 or 5 channel amp for example.

Yeah, I'm getting there! I'll probably have to work off the stock radio for a while 'til I can get a few bills paid. Never got rid of a car that still had a stock radio, so I'm sure this one won't be any different......all in good time! :D

Looks like I'll be using Nanook's suggestion in the short term with my first 2 channel amp coming in tomorrow (yay!!!!). Never really had subs in a car before, so I guess I'll find out after I get all this hooked up whether I feel like it is needed. Gonna be driving this one for a long time - might as well be able to enjoy it while I'm riding!!! :D I really don't want to run a sub box as I use the whole cargo area regularly. A stealthbox is a pricey option, but about the best aftermarket sub route to work with for my case.

Thanks for all the help, guys!!!! I'll add the JL components to the speaker listing post after I get them in & can indicate how easy/difficult they were to install.