Subwoofer Wiring

[BirfMark]

I'm trying to figure out what is involved with wiring in a real subwoofer & amplifier in my 93. I've searched, and keep coming up to references of bypassing the amp behind the glove box, wiring speakers, etc.

I have the factory head unit. I have the factory/stock subwoofer. The front door speakers have been replaced by a previous owner at some point, but I have no reason to think any wiring was ever modified in the system.

I want to add a new subwoofer and amplifier, but don't know where/how to wire it in. Will I be able to pick up speaker level inputs for the new amplifier at the stock subwoofer amp which is in the rear quarter panel? Is it as simple as unplugging the factory woofer amplifier & using those connections to find the high-level output (non-RCA) for the new amp? Anyone know what color wires I should be looking for?

Also, I imagine I'll have to run a new power wire back there, as the factory one isn't heavy enough to drive the new amp?

Thanks for any help,

-Mark

 

[Elbert]

I think you will have to run new independent speaker wires from your known good speakers and sub...to your amp. Then you will need the proper interconnect cable to connect the head unit to the amp. You'll also need the proper power wires to feed the amp. All of this is outisde othe factory amp and and speaker wires. Don't know what head unit you have...and I'm no expert but if its OME I doubut you have the proper RCA plugs for the aftermarket amp to connect to.

I think the OEM amps only interface and work with the OEM head unit...

Obvious quesitons

What type head unit do you have?

Are you planning on using the new amp to just power the subwoofer?

I thinik you may have limited options if you plan to retain the oem head unit with OEM amp.

I don't know what it would take to add new amp+sub to oem setup or even if you can do that reasonably. You also need to understand how you will control the on/off power of the amp.

I think you may find it worthwhile to change the head unit.

 

[C6H12O6]

Ditto switching head units. You are obviously adding a sub for a little better sound. No sense going to all the trouble trying to make modern amps and speakers work with a 15-year-old factory head unit. Get something with the bells and whistles you want (sub pre-out, maybe pre-outs for additional amp for door speakers, bluetooth for hands-free phone, iPod hook-up, etc.). Lots of good options out there.

 

[gotmud]

FWIW, you can add an aftermarket amp and sub using the factory wiring. The factory wiring behind the PS rear trim panel has all the connections you need to make this work. However, your amp will need to be relativly small (<50 watts output) due to the circuit rating and accept high level inputs (vs RCA), unless you add a high level to RCA adapter. The wiring code is below:

Wire Color Function
Red RR Input+
Black LR Input +
Red/Black Remote Turn On
Green/Black Sub +
White RR Input -
Yellow LR Input -
White/Black Ground
Gray 12+ ACC
Green/Red Sub-

 

[BirfMark]

What type head unit do you have?

Factory head unit - CD/Tape/AM/FM.

Are you planning on using the new amp to just power the subwoofer?

Yes - the new amp is a Rockford Fosgate Prime R150-2 amp.

I thinik you may have limited options if you plan to retain the oem head unit with OEM amp.

Limited in what regard? I guess I'm naive - since I don't understand what I could me missing, I don't even realize I'm missing it. Audiophile, I am not.

I don't know what it would take to add new amp+sub to oem setup or even if you can do that reasonably. You also need to understand how you will control the on/off power of the amp.

After talking to the installer at the local car audio store where I purchased the amp, he supplied me with a "High Power 2 Channel Line Output Convertor with Low Voltage Trigger Remote Output" switch that basically picks up the voltage to the rear speakers, and triggers the amp to turn on. This switch should theoretically be able to identify when the rear speakers receive power, and turn the amp on. This saves me from having to run a dedicated switch source back to the amp from the factory head unit. All I should have to run now is the main power lead from the battery. Hopefully I can pick up the rear speaker wires somewhere in the rear PS panel near the factory subwoofer amplifier.

 

[BirfMark]

Ditto switching head units. You are obviously adding a sub for a little better sound. No sense going to all the trouble trying to make modern amps and speakers work with a 15-year-old factory head unit. Get something with the bells and whistles you want (sub pre-out, maybe pre-outs for additional amp for door speakers, bluetooth for hands-free phone, iPod hook-up, etc.). Lots of good options out there.

Sub pre-out would just mean I'd have to run all my RCA cables clear from the new HU back to the amp, right? With the switch I purchased (see above post), I don't have to run these RCA cables, as I can trigger the amp power & convert high-level speaker inputs into RCA all right at the amp, provided left & right speaker wires are somewhat reasonable to tap into. I currently run my Zune off a simple cassette adapter, and have no desire to currently run anything Bluetooth through the system.

I can see down the road going through & totally revamping the system, but this 10" sub, new amp & switch currently have only cost me $150. If I can keep the cost down, I can save money for really revitalizing the system down the road with better components (head unit, door speakers, additional amp, etc).

 

[BirfMark]

FWIW, you can add an aftermarket amp and sub using the factory wiring. The factory wiring behind the PS rear trim panel has all the connections you need to make this work. However, your amp will need to be relativly small (<50 watts output) due to the circuit rating and accept high level inputs (vs RCA), unless you add a high level to RCA adapter. The wiring code is below:

Wire Color Function
Red RR Input+
Black LR Input +
Red/Black Remote Turn On
Green/Black Sub +
White RR Input -
Yellow LR Input -
White/Black Ground
Gray 12+ ACC
Green/Red Sub-

This is great - this is what I was kinda hoping to hear. Being the electrically-challenged though, can you explain what you mean about the circuit rating not being sufficient to power a larger amp? Are you meaning that the factory wiring simply can't handle the ameprage draw of a larger amplifier? I was planning on running a dedicated power wire from the battery back to the panel to power my new amp, but using the factory speaker wires & such to trigger/signal the amplifier, if that makes any sense?

Maybe I need to scan in the wiring diagram & instructions for this switch I picked up - it seems like it'll solve a lot of the problems people are saying I'm up against, if it works the way I think it does.

Thanks for the help so far!

 

[Elbert]

I think the inference to the circuit rating in regard to the new amp is talking about the power output of the amp in watts? Generally speaking the OEM speaker wires are fairly thin and thus only rated for "X" number of watts.

Assumption is that you would install dedicated new speaker wires from new amp to subwoofer. The question I would want to understand is: Can you run an aftermarket amp in parallel with the OEM amp. Guess you plan on disconecting the OEM subwoofer?

I think you can do what you are saying as long as you have a subwoofer signal, a power on source for the AMP, new speaker wire from the new sub to the Amp. But unsure of how you will in effect connect amp to head unit (technically). New amps use the inter-connect RCA plugs to connect from the head unit to the AMP. I know they make various adapters that noe can use . I think I would just pay the guy (pro installer) to set it up for you if the amp will work.

 

[BirfMark]

Assumption is that you would install dedicated new speaker wires from new amp to subwoofer. The question I would want to understand is: Can you run an aftermarket amp in parallel with the OEM amp. Guess you plan on disconecting the OEM subwoofer?

Yes - I'll be installing new speaker cable between my new amplifier & the new subwoofer. I had planned on disconnecting the stock subwoofer if needed, but the pro installer guy I talked to actually suggested using the outputs of the amp (to the OEM sub) as the signal into the convertor switch I have. The switch will convert the speaker wire output of the stock amplifier to RCA for the new amp to use.

I think you can do what you are saying as long as you have a subwoofer signal,

Yes - I should be able to get this from the OEM amplifier.

.. a power on source for the AMP,

The convertor switch thing I got has a 'trigger' wire that I can connect to "any one speaker lead. When radio is turned on, there will be approximately 6 volts DC on any speaker wire. The green wire will trigger at a minimum 0.8 volts." So that should solve turning the amp on with the OEM head unit.

new speaker wire from the new sub to the Amp.

Definitely new wire from the new sub to the new amp.

But unsure of how you will in effect connect amp to head unit (technically). New amps use the inter-connect RCA plugs to connect from the head unit to the AMP. I know they make various adapters that noe can use .

Sounds like this switch/convertor should still solve my problems. It takes the high-level speaker feed & converts it to RCA for my amp to use.

 

[Ivan80]

Your pro installer is pointing you in the right direction. Run adequate power back there and use the converter and it should work. The only thing I would add is that if you are going to connect the line-level converter you have to the OEM subwoofer amp output, you are going to end up with a single channel signal because there should only be 1 pair of speaker wires going to the OEM sub speaker. You should have a combined mono signal and this is all you need for a subwoofer application, but you'll need to pick up an RCA 'Y' cable to feed the single RCA signal output from the line-level converter to both the left and right inputs on your new amp (unless it has a provision for bringing in a single channel mono signal to just one of the RCA's).

If it were me, I would try grabbing the left and right signals from before the OEM sub amp and seeing if those work for you first. Just leave the wires long enough to splice back together in case it doesn't. That way, you could eliminate that extra equipment in the panel, and even mount your amp in that area.

I currently have one of my amps mounted to the stock sub/amp bracket. I screwed a small piece of MDF to the back of the bracket, and mounted the amp to that. Just make sure you have enough clearance between the amp and the quarter panel and fashion something to divert any water that may get in the panel through the sliding window over and away from the new amp.

 

[C6H12O6]

No offense meant here, but you are not being pointed in the right direction by your installer. You are wasting money on a set-up you will likely not be happy with. No matter what kind of voltage you have turning the amp on, that won't actually power the amp. In order to have the necessary voltage for the amp, you will need to run power wire from the battery straight to the amp. Even then, you'll need to run pretty decent gauge wire to avoid losing too much with that long of a run.

If you're willing to do that, running RCAs isn't that big of a deal. I know it's a slippery slope with the install... amp and sub leads to RCAs which mean a new head unit, which really sounds best with new door speakers, then you probably want new speaker wires throughout, then why not a big amp to run it all. Yikes. Big install $$$ to do all at once. I get that. Still, you'd notice MUCH more improvement spending your $150+install on new door speakers and some sound deadener for the doors. These big doors actually allow for pretty decent bass with good speakers and some Dynamat.

Not sure what you're looking for, exactly, but line-level amps and cheap subs sound like crap. The laws of electrical physics are just not working in your favor.

 

[BirfMark]

Well, I just finished running a dedicated 4AWG wire straight from the battery back to the PS rear panel. Way overkill for the little amp I'm running right now, but eventually I'd like to be able to run an inverter out of that area as well.

Unfortunately the subwoofer I'm using (Pioneer Premier TS-W1040C 10") is too deep to mount behind the rear panel, so it'll have to go in a box. I think I'll build a simple downfiring enclosure for it that will fit cleanly behind the third row seats.

I really don't want to start down the slope of running RCA's, as that alone would add easily over $200 to this install. Sure it'd be nice, but it's just not in the cards this close to Christmas. Hopefully the line level to RCA convertor I'm using won't detract too much from the sound quality.

 

[wakesetter]

I'm currently adding a sub to my system as well. I changed out the head unit and will be putting a Slim sub amp under the drivers seat. This allows for a shorter battery lead run and short RCA's. Then I am going to run the speaker wires to the right rear panel and put a slim box (home made) in there for a shallow mount Rockford Fosgate 10" sub. Just gotta get off my but and get it done.

 

[gotmud]

This is great - this is what I was kinda hoping to hear. Being the electrically-challenged though, can you explain what you mean about the circuit rating not being sufficient to power a larger amp? Are you meaning that the factory wiring simply can't handle the ameprage draw of a larger amplifier? I was planning on running a dedicated power wire from the battery back to the panel to power my new amp, but using the factory speaker wires & such to trigger/signal the amplifier, if that makes any sense?

Maybe I need to scan in the wiring diagram & instructions for this switch I picked up - it seems like it'll solve a lot of the problems people are saying I'm up against, if it works the way I think it does.

Thanks for the help so far!

The vehicle's power circuit (for the OE amp) is only rated at 10 amps (IIRC). Therefore your amp will need to draw less than 10 amps at its full rated output. I'm guestimating this type of current draw will be found in an amp rated at around 50 watts (perhaps 75 watts if it is a high end amp that is effecient).

Since you intend to use a dedicated circuit for your amp, this becomes a moot point.

 

[BirfMark]

Yup - everything is wired up now, and the amp is installed. I finished putting together the downfiring subwooofer box last night, so tonight I just have to paint it & install the subwoofer itself.

Gotmud - thanks for your help, all the wires needed to install an aftermarket amp are there in behind the panel just like you said. As long as someone isn't afraid of splicing/soldering some wires, an amp install is actually really straight forward. The only wire you'd have to run is the dedicated power wire, because as you suggest, the factory wire is simply underrated for any real amplifier.

For future reference, here's the factory wiring for the stock subwoofer amplifier (per GotMud & the FSM):

These wires are at the plug which connects to the factory subwoofer amplifier behind the USPS rear interior trim panel.

Right Rear Speaker, Positive (+): Red
Right Rear Speaker, Negative(-): White

Left Rear Speaker Input, Positive(+): Black
Left Rear Speaker Input, Negative(-): Yellow

Subwoofer Input, Positive(+): Green with Black tracer
Subwoofer Input, Negative(-): Green with Red tracer

Remote Amplifier Turn on/Trigger: Red with Black tracer (turns new amplifier on with stock head unit)
Chassis Ground: White with Black tracer (run a dedicated ground for new installs)
12 volt positive with key in ACC position: Gray (not used for new installs typically)

I took several pictures of my install - I'll post them up in the coming days.

 

[HntWhtTail]

I am a little late on this one but I did a Ghetto install awhile back and it still works perfect and sounds great infinity basslink 10 spliced into the factory sub wires. has been run hard for long periods of time and never blown a fuse. whole install took about 25 minutes as I remember.

 

[mgoat]

I did a Ghetto install awhile back and it still works perfect and sounds great infinity basslink 10 spliced into the factory sub wires.

Hnt - I'm just now reading your post. I'm interested in this solution. Could you post a pic. of what it looked like when you were done? Did you cut hole for it or just let it boom back behind that enclosure? Is it still running good?

Thanks

 

[rbryan]

I am trying to do the same thing, only having trouble getting the amp to kick on. Does anyone who has used stock wiring to add an aftermarket amp have a detailed picture or description that shows how your wired it and what volts you were getting at the 12V and Remote connections? Thanks!

 

[BirfMark]

Roy, sorry I was gone on vacation, just got back in.

To update this thread, the wires I used (from GotMud's description, and repeated in post #15), are the ones in the white connector on the top right of this picture:

I removed this connector from where it plugs into the factory amp, and then spliced in the wires I needed to the convertor I used:

You should get a full 12 volts at the red wire with the black tracer, which should be connected to the trigger or remote-turn-on wire of your new amplifier.

Hopefully that helps.

 

[rbryan]

That's what was buggerin me, I'm only getting a little over 2 volts on the Red/black remote turn on. Thanks Mark!