I am not ready to upgrade yet, but I was looking over the wiring diagram for the radio and amp. I have several questions if someone could enlighten me.

The rear speakers have 4 wires to them. Are they powered, or passive?

There are four wires coming out of the radio, pin 3,4,5 6B. I assume these are non-amplified output channels? Is it listed somewhere what location they are for? Does an aftermarket unit need anything special to use the OEM amp without causing damage?

Last, why is the ABS controller invlolved?

Thanks, James

 

Don't know if this will help or not but it's the first thread that came to mind.

THREAD

 

Ths stock infinity amp is a 6 channel amp (6 x 22 watts @ 4 ohm)
2 channels go to the front system (6.5" woofer and a tweeter)
The tweeter has a very simple 1 capacitor x-over.
4 channels go to the 2 subwoofers in the rear. They are double coil woofers.
You can also bridge the 4 sub channels if you want to replace the stock subs.
But it will be very hard to find 6.5" sub chassis thet fits to the stock mounting.

The infinity amp has a simple integrated processor which contains a x-over for the subs and a fixed eq for all speakers. So if you want to replace hm you have to think about the x-over and eq.

The hu out is a high-power output.
If you want to replace the hu, you'll have to use the speaker outs; not the chinch outs.
There are no problems with 50 watt hu's or so. Nothing special needed.
To replace the original hu, you'll need a special tool for Becker radios.

The signal from BCU/ABS is used for an automatic volume adjustment by the amp.
If you drive faster, the volume of the amp is higher/louder.

 

Lesson 1: Radio is the one part of electronics where you can make current flow in an open circuit!

So they ARE passive. I was sure (but never cared enough to check) that they were supplying power to small amps in the speakers themselves. (I've seen that done in the 70's and 80's in Land Mobile Radio to allow an auxiliary speaker to run at somewhat higher power output than the original design called for.)

But double coils? In 30 years of working audio PAs of up to 1,000 watts, I have never seen this before. (My only experience with high power audio is in outdoor weather warning sirens.)

What is the idea of running two coils? What are they trying to accomplish and just how common is this?

 

JL Audio - Car Audio Systems

Here's a basic intro to dual coil speakers and why they're used. They're extremely common in home theater subs.

Why they're used in the Crossfire, I don't know. None of the use cases presented in the linked article seem to have needed to apply and I can't see/understand the advantage. Maybe it was easier to output 2x22W on the amp than one higher-powered channel?

 

As far as i know the infinity amp itself was in used in other cars too, but with another software. So they just adapted it for the Crossfire.

Attached some pics of the sub. So you can see it's a double coil speaker and it's wired as double coil.

 

Guys,

Thanks for all your help/expertise on this one. This place is great for information. I will continue to follow this thread. I'm learning something new everyday 'bout this car...

James

 

Me neither.

 

I see that, but didn't doubt you.

 

bri3D, The reason for dual coil on the subwoofers is more power. A car amplifier with no boost power supply is limited to about 9 Volts AC output. One amplifier on a two Ohm speaker is about 40 Watts. Two amplifiers on two Ohm coils is about 80 Watts. The Crossfire has two subwoofer speakers with dual coils, so there is about 160 Watts for bass in the car.

bigblock427, Yes, the Crossfire amplifier was used in the 2002 through early 2004 Ram pickup trucks. The Crossfire has different parameters for the DSP. As you can see in a photo of the amplifier card in another thread, the DSP is a sharc, a top of the line processor.