It'* not a subwoofer, but a gain control for the amplifier for the woofer part of the rear 6x9 speakers.

You would have to get a free-flowing sub wouldn't you? A regular sub wouldn't work all that well, unless you built a box behind it and attached it to the rear deck.

Here'* an easy way to use the gain control and keep everything looking stock.
You remove the wires from the "subwoofer" section of the 6X9'*, run them into an amp with a high level input and into a sub box. I have a sub box with a single Mmats 10" and a Rockford amp behind the back seat so that the sub lines up with the armrest hole and pounds into the car when the armrest is down. The flat plastic piece with carpet on it snaps out of the armrest area to make it look better.
Let me know if you want the wiring code for the sub wires.

The amplified speaker system has amplified dual-coil speakers in the back with subwoofers, as listed in the factory service manual. They are actually 3-way speakers when you consider the tweeter. The subwoofer amplifier is under the radio.

Those factory "subwoofers" are just 6x9 woofers and you know it! They aren't bad but they don't play low enough frequencies to be considered a true subwoofer.

So the 6x9'* don't push out low enough frequencies. That doesn't mean the subwoofer amplifier doesn't push out low frequencies. Wired into speaker level inputs on an aftermarket amplifier, you could have a nice system, with a low price and keep everything stock looking...
And then amplifier IS a subwoofer amplifier because if you wire a sub to the wires from the amp, and you'll see it is in fact a subwoofer amp, just isn't very powerfull because it is designed to pump a second coil in a 6x9, not a 500watt 12" subwoofer..

High (speaker) level inputs won't sound nearly as good because the signals gone thru the amp already. And most aftermarket systems (especially these cars) use very weird power, and resistance settings so you might not be able to do it. I think the main thing here was to wire the slider into your amplifers remote bass ****, or replace it.

Well, what can I tell you; I'm just quoting the factory manual and the term _they_ used...

So if you have done it with an after market amp..... how?

Thanks!

it was me except i took the gain control out and put a eq in there