Without running new wiring or replacing your head unit.
Purchase 6.5” Components with crossovers, amplifier of your choice, and some amp wiring.
Install fuse block and run power wire for amp (see other DIY’s). I went under the passenger seat for this install, as it is a good central location between the battery and where all the wires are for the BOSE Amp.
Remove carpet, plastic piece, and black foam (under strut tower bar, pull hard) from the trunk. You can also tap one of the unused bolts under here near the passenger side for the ground for your amp. Run it down through the passenger side under the plastic interior piece then pop it through the carpet, into your amp.
Remove two bolts and two nuts from the BOSE amp, flip it over, and unplug the two cannon plugs.
Line in to BOSE Amp, strip back and tap (do not cut completely):
- White for Amp Remote – run it down to the amp in the same path as your ground wire.
Line in to BOSE Amp, clip completely and splice into RCA Connectors:
- Pink is Front Left +
- Blue is Front Left –
- Red is Front Right +
- Green is Front Right –
Make sure they are long enough to go from the BOSE amp plug down to your amp.
Line out from amp back to speakers, clip completely, splice into standard red and black speaker wire, and label:
- Purple and Blue pair is Front Left Speaker
- Light Green and Grey pair is Front Left Tweeter
- Orange and Green pair is Front Right Speaker
- Black and White pair is Front Right Tweeter
These don’t need to be as long, since you will put your crossovers in this area.
Install your components. At the speakers, just clip and splice the factory wiring into standard connectors. (See other DIY’s). FYI I made my own 6x9 to 6.5” adapter plate using the BOSE speaker mounts and about $6 in plastic with a dremel.
Connect:- Newly spliced RCA connectors into amp front left and right channel.
- Run two pairs of speaker wire from the BOSE amp area down to your amp, connect to amp left and right output. Back near the BOSE amp, connect these wires to your crossovers input.
- Connect the newly spliced speaker and tweeter wires from the step above into your Crossovers output. Secure your crossovers with double stick tape.
Reinstall the two cannon plugs back into the BOSE amp and reinstall the amp with the two nuts and two bolts. This keeps your BOSE sub thumping until your next paycheck when you have funds to upgrade it.
Double check all connections, install amp fuse, and crank it up!
Check that everything works, put your interior pieces back together, and secure your amp.
Sorry for the lack of pics. I did not really intend to make a DIY out of it when I was doing it, but I have gotten a lot of requests to write it up, so here it is. If you have any questions, I will do my best to answer them here. I also had a witness to the install, thanks for the use of your garage CBTech.