speaker out to preamp out while driving speaker
 

Hi I have a technical question....

I want a single binding post input on a speaker with built in sub. I need a way to drive the preamp input on the sub amp from the speaker binding posts.

Should I use a resistor or a step down transformer? I need to not interfere with the speaker, and also need to not blow up the input board on the sub amplifier.

Anybody know of a good product for this?

How about a Radio Shack car radio "Line Out Converter" ? old number # 12-1338

I think this is made to emulate a speaker's impedance. I need an output in addition to the speaker being driven.

oh and I think most of the premade car audio boxes are limited to 30 watts or so. I need to be able to handle a lot more power.

Ok transformers are out. They don't operate at that low of a freq. Anybody ever use a big resistor for this????