Built-In Amplifier

Someone please help...

I have four speakers in my car and want to amplify the signal to the
rear speakers only. The obvious thing to do is get a two channel amplifier
and simply connect it up.

However, my Head Unit (JVC KD-SH99R) has a built in amp, and it states
in the manual, if you connect the unit to an external amp, you should switch
the built-in amp off. If I do this however, I will loose the sound signal to
the front speakers, as they wont be connected to the external amplifier.

Is it possible to leave the built-in amplifier on (to get sound to the
front speakers), and still connect the rear line-out connections on my Head
Unit to an external amp, to get amplified sound from the rear speakers?

Will leaving the built-in amp on effect the signal sent (via RCA
leads) to the external amplifier in any way?

Will the Head Unit even give out a signal to the line-outs when the
built-in amp is on?

Thanks for any help

"AS" <AS@IF> wrote in message news:1064943432.62958.0@damia.uk.clara.net...
> Someone please help...
>
> I have four speakers in my car and want to amplify the signal to the
> rear speakers only. The obvious thing to do is get a two channel amplifier
> and simply connect it up.
>
> However, my Head Unit (JVC KD-SH99R) has a built in amp, and it
states
> in the manual, if you connect the unit to an external amp, you should
switch
> the built-in amp off. If I do this however, I will loose the sound signal
to
> the front speakers, as they wont be connected to the external amplifier.
>
> Is it possible to leave the built-in amplifier on (to get sound to
the
> front speakers), and still connect the rear line-out connections on my
Head
> Unit to an external amp, to get amplified sound from the rear speakers?
>
> Will leaving the built-in amp on effect the signal sent (via RCA
> leads) to the external amplifier in any way?
>
> Will the Head Unit even give out a signal to the line-outs when the
> built-in amp is on?
>
> Thanks for any help
>
You may have to connect the rear speakers to the ext amp only.

I did this and using connectors left the car speaker wiring ready for
re-connection if you sell the car on. I just taped the connectors so that
they can't touch each other OR the body work. Ran speaker wiring to each
side from the amp and connected to the speakers.

So I've gor rear doors speakers powered from an amp under the passenger seat
and separate amp and sub in the boot.