ok so im getting tired of the stock radio sound in my 03 sedan and final have some equipment to install. i want to leave the stock headunit for now, but i have a 4 channel MTX amp that i want to power the stock speakers, and a mono MTX amp for my sub. does anyone know how to hook up both amps to the stock hu? do i need 2 LOCs (line out converters)? and do i have to run new speaker wire from the 4 channel to the speakers? any help would be appreciated!! thanks!

 

Bose or non-bose headunit?

If you've got bose, see this post:
https://g35driver.com/forums/audio-v...se-system.html

If you don't have bose, tap the wires at the back of the headunit, send them to your trunk to the amplifiers (through a line out converter) and then back to use the stock wiring.

 

bose unit

 

Ok, then just follow that link above, and you're good to go for most of the wiring, and use this one here:
for the wires to tap for the speaker signals:
https://g35driver.com/forums/audio-v...rams-pics.html

 

i found that and started to wonder how to install a 4 channel amp to my stock speakers. i read how to hook up the sub and i think im good there

 

got it so i just tap my 4channel into the correct wires that are leaving the bose amp right?

 

so im still confused where i hook up the LOC for the 4 channel, and do i need 2 of them?

 

Yeah, after the bose amp, unless you happen to have an amplifier that takes differential-balanced signals.

 

so where do i hook up the LOC? do i need a special 1 for a 4 channel??

 

You can prob just use two 2-channel converters OR a single 4-channel converter. Depending on the brand of the converter you go with it might be more budget friendly to get the single 4-channel.

HU => original speaker wires to trunk => Line Level Converter(s) => MTX 4-channel => original speaker wires to speakers => speakers of your choice.

If you tap the line level signal to use for your single-channel MTX amp just be sure the voltages are within range acceptable by the amp (shouldn't be an issue though).

This is a pretty basic setup. Depending on how much watts your setup is using you may want to add a 1 Farad capacitor.

Disclaimer: I am not a CAR audio tech.

Please see my post #12 below for further clarification. Reading this post only may lend to misinformation.

 

thanks this really helps! now to find a 4 channel LOC! im going to assume online is going to be my best bet
thanks again to wrathernaut and rajen!!!

 

If you're on a budget then maybe something like Scosche's SLC4 would do, but I would better recommend something like AudioControl's LC6i where you would have a third output channel for your subs with a trigger signal to turn on your amps.

One thing that I am unsure of is whether the signal from the factory HU going to the Bose amp is line level or speaker level. I am trying to avoid having to use a LOC after after the Bose amp--I wouldn't want you to have to still use the Bose amp.

If the voltage from the HU before the Bose amp (2 volts?) is less than required by your amps then you may need a line driver instead of a LOC, otherwise, if possible, you would just solder on RCA connectors and go directly to your aftermarket amps.

In the end you would most likely need to use aftermarket speakers as the Bose speakers have an odd impedance.

I apologize if this is confusing. If someone knows more than I do please offer advice.

Regards,
Rajen

 

yea sounds like a major headache. all im trying to do is salvage my old equipment : MTX terminator TN400/4 4-channel, MTX JH600 JackHammer mono amp, and a 10" sub. now i know most of this would be a lot easier if i just replaced the stock headunit, but the price is a little to steep. i plan to change it out eventually, but for now this is what i have to work with

 

This is some good advice, I bought a 4 channel scosche:

to tap into my front speakers and subwoofer wires (stock bose powering stock rear speakers). I just did a quick search and 6 channel LOC's are pretty expensive, so I would just go with a 4 channel for front/rear speakers, and a 2 channel for the sub.

If you don't want to run new wires like me (getting speaker wire from door to trunk is a pain in the ***), you can tap into the original wiring. For example, I will explain what I did for the front right speaker.

First, I got the signal from the HU to connect it to the LOC by disconnecting the wire harness in the trunk left of the spare wheel, looked up the wiring diagram, and cut off the +/- cable for the front right speaker INPUT, spliced it, and connected it channel 2 (channel 1 would be for front left).

Then, I connect RCA cables from the LOC to the amp RCA input.

Next, I lookup which wires are the front right OUTPUT, and spliced wires to go from the AMP to the the +/- of the front right speaker OUTPUT signals.

If you have aftermarket speakers like I do, you need to cut off the wires at the door and splice those cables and connect the new extended speaker cable to your new speakers.

Let me know if you have any questions, I just did my install last month and have some pics as well.