Aftermarket amp and battery question

[bondheli]

I am going to be using an aftermarket Head unit and aftermarket amp for subwoofers only. I will use the stock amp for the rest of the speakers.
Since I already need the "amp on" pin for the stock amp, what do I do about the new amp? Can I just splice the new amp's "amp on" cable with the old "amp on" cable?

Also, I have my battery under the front hood; how should I run the positive cable for the new amp? If I'm running 600 watts, is it safe to splice into the old amp's positive power cable?
thanks

[bondheli]

bump

[pundit]

I am going to be using an aftermarket Head unit and aftermarket amp for subwoofers only. I will use the stock amp for the rest of the speakers.
Since I already need the "amp on" pin for the stock amp, what do I do about the new amp? Can I just splice the new amp's "amp on" cable with the old "amp on" cable?

Also, I have my battery under the front hood; how should I run the positive cable for the new amp? If I'm running 600 watts, is it safe to splice into the old amp's positive power cable?
thanks
E34 Subwoofer install (http://www.bmwe34.net/e34main/upgrade/stereo_subwoofer.htm) ;)

[Mobius]

I am going to be using an aftermarket Head unit and aftermarket amp for subwoofers only. I will use the stock amp for the rest of the speakers.
Since I already need the "amp on" pin for the stock amp, what do I do about the new amp? Can I just splice the new amp's "amp on" cable with the old "amp on" cable?Yes. Only way to do it.

Also, I have my battery under the front hood; how should I run the positive cable for the new amp? If I'm running 600 watts, is it safe to splice into the old amp's positive power cable?
thanksThat's a lot less fun than running it to a battery under the rear seat. For 600w, you most certainly cannot use the teeny power line for the factory amp.

You'll have to run a suitable (6 or 8ga) positive cable through the runners below the door sills to the engine compartment. You need to find a hole in the firewall to pass this cable through, too. Not very fun.

Also, be sure to run this power cable on the opposite side as you run the RCA cables - though for a sub amp it's not going to be a big issue. Typically, running RCAs for any length in close proximity to a power cable will cause a good bit of interference and 'alternator whine'. It's only in the higher frequencies, though, so a crossed-over sub amp should filter it right out.