Sub options with factory JBL system

2015 Prius 4 with the factory JBL Greenedge system.

I've seen the notes from people who have attempted to make changes to the factory speakers in the JBL system. Since the extra Greenedge amp not only amplifies and crosses over the signals between the speakers, changing out the individual drivers doesn't work out.

I like the idea of adding one or two of the small enclosure subs that can be mounted under the front seats. My only question to anyone that has done this is other than adding a larger speaker(s) for the lower frequencies, how does it help the other drivers in the car. As I see the setup, I would be tapping into the + and - speakers for the front bass drivers to send to an amp for the sub. All of these systems offer a crossover to only allow the frequencies below a certain point to the sub but aren't you still sending that full range to the front drivers? Part of the beauty of subs in a system is it takes the work of those low frequencies away from the smaller bass drivers and allows them to only work on the "mid-bass". Unless there was a powered sub that offered a passthrough of the high level output and would cross over that amplified signal back to the in door drivers, I don't see a way around that.

I'd thought about bass blockers for the remaining speakers but the lowest frequency model I've seen (150Hz) would actually work at about 300Hz at the ~2 ohm load the speakers are running at. I think that's a little high for a sub to pick up the difference.

I know some have done this already and the reports I see here are it's worth it. Maybe I'm overthinking this and should just hook it up and let my ears decide?

 

BTW,

JBL has a quick breakdown of what they have in this system. It's not very detailed but it gives more info than I've seen from Toyota.

JBL Automotive: Toyota Prius

 

Thanks for the reply and that's the model I'm looking to add as well. Do you recal the color of the + and - cables for the front woofers in your change or that you tapped into?

 

Thanks for the info. I ended up getting the Kicker sub and installed it under the passenger seat. Since the JBL amp was under there it was a good spot to pick up the woofer cables I needed and other power related items. Here's some of the things I did for the install.

- Completely remove JBL amp, mount and shroud
- Cut back plastic of underseat hear vent. I was able to fit the Kicker box inbetween the two ridges that are built into the floor after doing this. I also stuck a sock in the vent to keep some of the hot air from blowing on the speaker.
- Put a few Velcro pieces on the bottom of the Kicker. These hold very well to the carpeting.
- Zip tied the JBL amp to the seat frame. There is enough play in the cabling to allow free seat movement.
- Ran the remote turn on of the Kicker to the 12V plug in the center compartment.
- While in there, ran the cable for the Kicker's remote volume and mounted it in the center compartment.
- Main power back to the battery and under the carpet/door sill plastic.

After tapping into the positive and negative woofer channels for the front speakers and powering everything up, I'm happy with the way the sub rounds out the sound of the factory JBL system. I still need to tweak the settings a bit for crossover and boost but the Kicker is well worth the install and basically takes up no extra room in the car.