Hello Folks
I recently purchased a 2002 P38 and had the original radio replaced with an Alpine unit that would allow bluetooth connection for the phone.

I find that I can't adjust the front/back balance on the sound because the audio dealer tells me that the original RR amp, which they are using, is only a 2-channel device.

I notice that the nav system gives instructions over the speakers and dims the audio when it does so. My question is, is this audio insertion BEFORE the amp, in which case, if I install a 4 channel amp for separate front/rear operation will I still hear the Nav system clearly over the front channels, or is there a separate input to the factory amp for Nav and I risk losing Nav commands entirely??

Thanks in advance,

 

Two channel amp? That's crap. How would the factory system have a fader with only 2 channels? The P38's typically use an amplifier at each speaker and the subwoofer just to make sure there is more to go wrong. If you hook up an aftermarket head unit through the factory amps, you typically need an attenuator circuit: Aftermarket Head Unit Adaptation for Range Rover 4.0/4.6

The other system they use, which you likely have, is the DSP with an amp located near the subwoofer. Check this thread. If you are a member, you can even access the diagrams: http://www.rangerovers.net/forum/7-r...ns-wiring.html According to this thread, the DSP system uses a digital signal from the head unit to tell the amp how to adjust the levels to each speaker. Brutal. Without that signal, the amp will have the same output on each channel. It is likely that the audio shop didn't know how the factory system worked because hardly anybody does. As for the nav input, it is before the amp so swapping out to another amp will cut off the sound. This is also discussed in that thread.

 

Thanks for the info. I need to look at my model to see if it's the DSP amp type or amps in the doors type. Since it's one of the last P38s I suspect it's the DSP type. Looks like I need to have a longer conversation with the audio guy before I invest some $500 in replacing the amp.

 

I edited my post based on some info I found on the later P38's. I had a late 1999 and it used the amp at each speaker approach, but you have the DSP. Check out the link and be amazed. Or terrified. You'd think that Rover would have learned that typically more electronics isn't the answer.

 

Thanks for the link. I'm now certifiably terrified!
I'm going to pass all this over to my audio guy and see if he can work it out.