alpine cda9807 and crossfire ct2160

hows it going, i recently purchased a used alpine cda 9807 and it works great, but does anyone know if there is a sub crossover on this unit, it seems to be playing full range even with the bass control set a 60 hz. also on the crossfire, which i have running a 12 inch sub off the sub outs on the 9807 only plays well if one of the rca plugs is unplugged from it. if i plug in both rca's output drops signifigently. Any ideas on what things to check?
thought about doing that

but will have to wait until tommorow at work, will let you know results. Thanks for the help. Will also throw this in, when i first start the car the sub thumbs twice like turn on thumb, even when the subwooer control is off. Would be interest to know if there is a way to test all my grounds?

Perry Babin

Paid Member
2003-11-20 11:01 am
If you think the ground is open, you can use your multimeter set to ohms. Place the black probe on a known good ground and the red probe on the ground terminal of the piece of equipment.

If you think the ground is insufficient, do the same but set the meter to DC volts. Drive the equipment (generally an amplifier) to high power and monitor the DC voltage. Ideally it should never be more than a few thousandths of a volt. If it's more, you need to reduce the resistance in the wiring between the amp and the ground point.
Here's a manual

You can apparently turn the subwoofer preouts on and off (??) (p.11), and you can turn off the internal amp if you have all external amps (p.13).

But I don't see mention of a crossover.

For the rest, it would help if you described your whole system-what connects where, from the head unit to the amp to the speakers and the sub.