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Has anyone happened to do a How To while wiring up your subs

Posted: Mon Feb 20, 2012 10:16 pm
Hey y'all,

I'm just about to buy a new sub/amp setup as I am having really bad seller's remorse after selling my system about a year ago lol The deal can't be passed up and both the amp & sub are in near perfect condition.

In the past, I have had a system in every car I've ever owned, but I always paid a shop to install, which usually costs me anywhere from $75-100. This time, I'd love to wire up the Neon myself to save a few bucks.

Here's what's going in:
(I have already upgraded all 4 interior speakers to Alpine Type-R's and love their sound quality & clarity! So I am sticking with the Alpine brand, and staying consistent with the model Type-R)

Amp model: MRP-M500 (300w @ 4ohms, 500w @ 2ohms)

Sub model number: ALPINE TYPE-R SWR-1243D 12" DUAL 4-OHM

Now, the amp is already pre-wired at 2ohms so that part is done. I basically am looking for help on wiring the RCA outputs from the HU and the remote power wire. I haven't taken out my stock HU yet, but by looking up the P/N I see that the back of our radios do not have RCA/Sub Outputs, it only has the one factory harness connector slot. I need some sort of adapter to convert the factory harness, correct? Does anyone know where I can buy this? (BestBuy? Crutchfield?) By reading the wiring diagram, I'm guessing that for the '03 SXT I use the Pink + 12V wire for my remote power wire? Or is it the Red/White radio ignition wire?

This info. would be really helpful! :thumbup:


Posted: Tue Feb 21, 2012 8:48 pm
by Dabuh
Hey, glad to see you are looking to add a sub, it is going to make a world of difference. Nice choice on equipment btw, I have the same setup...

As far as the RCA connections, these are going to be plugged into a line out converter, which I recommended hooking up behind the radio (incase you ever decide to put an aftermarket radio in with outputs it will be easy to remove and hook up to the new radio). You can buy a LOC at bestbuy (I'm an autotech there) or crutchfield. Do not buy the one that generates a remote turn on wire, they suck. Hooking it up is easy, there is a white and white/black This is going to go to your left rear speaker wires (black stripe means negative side). The grey and grey/black will go to the right rear speaker outputs. You may have some brown wires on the LOC, these are not required and do not generally ever need to be hooked up.

The amp you purchased has a built in LOC but I would not use it, the quality is not so great because they use resistors instead of transistors to drop the voltage.

The remote turn on wire is going to be connected to your ignition wire, again behind the radio, for the same reason.

The +12v is going to be connected directly to your battery then to the +12v on the amp. Do you have a Manual or Automatic? If it is automatic then all you have to do is drill a hole through the clutch plate, if its an automatic then its going to be a little harder (remember check twice drill once). You may need a right angle drill its kind if tight under there.

GRN is going to go directly to the chassis, Please do not connect this to a seat belt bolt, that's a terrible ground point. Make sure you brush all of the paint off of the metal. Screw it in with a self tapping screw, again check twice before drilling, you do not want to puncture your gas tank.

Please do not run the +12v wire through the door jam, I have seen this way too many times and this is not the right way to do it.

Any other questions feel free to ask...

Posted: Tue Feb 21, 2012 9:01 pm
by Caraudioholic24
Line output converter will work for what you are trying to do but if you want to make the car sound a lot better you may want to save yourself the headache and swap in another radio. This will liven up the entire system.

I have rca converters wire rcas a few radios etc. they are all in my audio for sale thread.

Need anything let me know

Posted: Tue Feb 21, 2012 11:35 pm
Thanks for the info guys :thumbup: you confirmed exactly what I was thinking.

Dabuh, the only thing you suggested different (and I guess all in all easier) is using my rear 6x9 Alpine Type R's for my RCA/Signal Input rather than using the back of the HU? I just figured since I would be running the power wire up to the HU anyhow, that would have been the best bet for the RCA's. Now, if I do it your way, using the rear speakers, the sub will lose signal if I fade it all the way to the front, right? (This might be a good thing...if and when my mum rides in my back seat, she used to always complain about the old system being too loud and vibrating her insides LOL)

Is this the LOC you're referring to?

Posted: Tue Feb 21, 2012 11:54 pm
by Caraudioholic24
You can tap into any speakers behind your headunit...but your best bet is too hook them up to the rear speaker lines this way you can fade out the subs (and the rear speakers). if you wanted you could get a toggle switch as well to turn off the amp when you don't want the sub amp on.

Hooking them up behind the headunit will make life much easier for you when you do swap the radio for an aftetmarket one...

That is the correct line converter you will need...if you wanna save a couple of bux. I have like 20 of them in my shed along with rcas cables remote wire me and let me know

Posted: Wed Feb 22, 2012 10:46 am
by Public Disturbance
For the best sound quality get a good aftermarket headunit with 4v line outputs already there.

Posted: Thu Feb 23, 2012 4:35 pm
by Dabuh
Caraudioholic24 wrote:Hooking them up behind the headunit will make life much easier for you when you do swap the radio for an aftetmarket one...
You should be hooking it up behind the head unit but attach the actual wires to the rear speaker outputs behind the radio. (as stated by Caraudioholic, this is going to make your like so much better when you replace the factory radio)

I am not a big fan of scosche products (unless its a dash kit), they are ussually cheaply made.
Check this one out. I have used it countless times and never had an issue. ... &cp=1&lp=1
I just figured since I would be running the power wire up to the HU anyhow, that would have been the best bet for the RCA's.
You shouldn't be connecting the amplifiers power wire to the radios power wire, this circuit cannot handle the current from the amplifier, you want to connect it directly to the battery. You probably already knew this but I just wanted to clarify.

I don't want to push you into buying something you dont really want but.....
Just like everyone else is saying, you are not going to get everything out of those speakers without getting an aftermarket radio. Also those speakers have quite the high power rating and would benefit from being amplified by a 4 channel amp, even with an after market radio.

Posted: Thu Feb 23, 2012 7:51 pm
by Caraudioholic24
I have 4 available LOL

Posted: Fri Feb 24, 2012 6:56 pm
Well, I got the sub wired up today and it sounds excellent! The front & rear Alpine Type R's really has a crisp, clear quality to them, along with a little bass to themselves for just being 6.5s & 6x9s. The Alpine 500w amp and one 12" Alpine Type R subwoofer really compliments them, perfectly. Right now I have it wired up as 2ohms - which seems to be a little bit more bass than I'm wanting, even with the bass turned all the way down/off, my mirrors still vibrate :thumbup: I'll be messing with the gain tomorrow after work to see if I can get it perfectly to where I want it. Thanks again for all of your help guys! Much appreciated, as always. :)

Posted: Fri Mar 02, 2012 10:57 pm
Well after a lot of shopping around and debating, I have finally chosen a head unit! :) I really wanted to find an Alpine HU to stay consistent...but their looks & options just weren't doing it for me. :-\

I went with the JVC Arsenal KD-AHD75BT - $199.99 @ the Crutch w/ free installation gear

General features:
-- CD receiver with AM/FM tuner with 6-AM 18-FM Presets
-- built-in HD Radio™ tuner
-- included Bluetooth adapter for hands-free calling and audio streaming
-- USB 1A connection provides extra power for charging devices
-- built-in iPod/iPhone control
-- control PANDORA® from your iPhone, Android, or Blackberry smartphone
-- built-in MOSFET amplifier (20 watts RMS CEA-2006/50 peak x 4 channels)
-- Separated Variable Color display
-- remote control

Audio features:
-- 24-bit digital-to-analog converter
-- high- and low-pass filters
-- 3-band parametric equalizer

-- inputs: front and rear USB ports, front auxiliary input
-- outputs: 6-channel preamp outputs (4.8-volt front, rear, subwoofer)

Other features and specs:
-- CEA-2006 compliant amplifier
-- compatible with most factory steering wheel audio controls (adapter required)
-- warranty: 2 years
-- Our 60-day money-back guarantee (

The MAIN thing that attracted me to this radio was that it has the capability of over 30,000 color changes PER SIDE (buttons OR text display) including can match any OEM dash color that you want or have the colors on a constant rotation! :thumbup: Plus it has every single option I wanted in a new radio (BlueTooth + HD-Radio Tuner (harder to find), Front Aux/USB, SiriusXM Radio Ready (I've had XM for years now and bought the specific Roady XT receiver b/c of the 7 color capable), Pandora Radio, iPhone charging/support, CD/Radio Text Display, 3 RCA outputs for my subs & if I choose to buy another amp for my speakers, and so much more.

Here's a couple pics: