How to connect subwoofer to JBL amplifier - 2010

This weekend, I successfully added my Boss powered subwoofer to 2010 Prius with JBL amplifier.
Let me share since this took a lot of searching and trial.

First, the JBL amplifier is located under the PASSENGER seat. It has a plastic cover over it, held on with two plastic rivits. Slide seat all the way forward and remove the plastic parts. Save to reinstall later.

The low frequencies are on the blue/middle connector. Black (Left+)/Yellow (Left-), and Red (Right+)/White (Right-). I tapped in to these speaker connections and ran to high level input to my powered subwoofer. I insulated and secured using hot glue sticks. I'm sure there are better ways. First attempt, I used the white connector on left, which had same color wires, but these go to tweeters, so crossovers filtered out the lows already.






Closeup of blue connector with wires attached to red/white and black/yellow wires.

I ran power to subwoofer directly from +12V battery, located next to storage bin on passenger side of trunk. Normally this is light blue wire in this vintage of Toyota. You want to be able to pull enough current without worrying about wire loss.

For switched "accessory" power, I grabbed it from grey wire under drivers seat (Satellite/media electronics).

Stereo sounds great now. Much fuller sound, like the bands just hired a bass guitarist and drummer!

 

The Boss1200 is low profile, so I have it sitting behind drivers seat right now, but that will limit leg room in back seat. Also going to try the hatchback/trunk and see if I hear or feel a difference.

 

10/30/17 Update: Found the Boss interface to balanced JBL amp was a problem. Really needs isolation transformers. Moving the Boss to wife's Camry and using Kenwood amplified bass tube in the Prius. Works well!