2020 Bose Cerwin Vega Sub Install

BeerCzar

I got my 2020 Touring 370z back in December of 2020. It came with the Bose installed. While the stereo is not bad, it lacks depth. I wanted deeper bass. The Z also has a lot of road noise, and the fake engine noise does not help.

I looked into the Bose system and read forums and other info on the Internet. Reviewing the wiring diagram, the Bose amp seems to be the key to a least two of my issues. It appears that Bose head unit is just that, a head unit from a sound system perspective. It cannot be ripped out and replaced without impacting some other functionality.

But from a sound system perspective, all the low signals go from the head unit to the Bose amp. I decided to install the Cerwin Vega spare tire subwoofer. According to the wire diagrams, the Bose amp had it all, amp power-on signal, low (RCA) rear speaker signal, a way to kill the fake engine sound, and stop the raising and lowering the volume.

From this experience, I wanted to offer what I learned.

Download and research every part you are going to touch using the repair manual. I used the 2016 manual. It is all in there you have to look.

Buy a good set of plastic auto trim tools. Do not use metal.

Watch lots of videos, some are good, and some suck, but even the sucky videos had little tidbits.

The only cable I had to run was the power cable. I bought a kit that was suggested when I bought the subwoofer. I do not know the cost difference, but I would have been better off sourcing the parts. The kit did not offer any splicing or butt connectors. The speaker wire included was useless, not only because I did not need it, but it was too small of a gauge for car audio. Also, the loom provided was horrible and not long enough to make the journey.
When working on the power cable, I did not feed the power wire along with the other wires going through the firewall boot near the battery. I poke a small hole in the boot and fed the wire. I watch the video on the install, while this is not suggested, I have done it on other installs with no issues. It is up to you if you want just to punch a small hole or back the tape off and then feed the wire. If you decide to feed the wire, I would make sure it is not flexible or use a wire snake to pull the wire through. It is a tight fit, and a flexible wire will be a pain to push, though.

When removing the plastic in the battery compartment, be careful not to break the small pin near the windshield. I broke mine. Make sure to look at the repair manual to make sure you understand where all the clips and things are at.

I used a cable splicer to splice the rear speaker wires to feed to the subwoofer. I used single pieces of wire for the splice and then used the heat shrink and solder butt connectors, they are way better than crimping, to connect to the RCA cable. You will need a heat gun.

I also used a splicer for the amp turn-on.

The controller for the subwoofer went into the document holder behind the passenger seat. A small panel pops out that you can make a notch in to pass the cable.

For the fake engine noise, I pulled out the engine speed wire. I bought a terminal ejector kit, but I could not get the wire out. Pure force using a Kelly clamp finally removed the pin.

For the road noise, I used Amazon Basics Car Sound Deadener Bulk Pack with Installation Kit. It has helped. I have only done the rear compartment. I am planning on doing the doors as well in the future. It would be best if you made sure to cover as much as possible. The roller provided marded and dimpled the material. I had a smooth J roller which did a great job on securing the damping material. Make sure to clean the surface to help with adhesion.

The subwoofer did cause a bump in the truck. It sticks up just a little. I even removed the rubber spacers from under the spare tire. It is not a big deal.
I think someday I may replace the Bose amp with an upgraded amp and replace all the speakers and wire. But for now, the sub is awesome and well worth the trouble to install.

I could have installed the subwoofer in a day. The noise-damping took a lot, and it was hard on my back. I had to keep climbing in and out of the truck area and bending over. I spread this out over a few days. I think you could get it done in a day and a half as well.

I hope my experience will help you decide to install the subwoofer, remove the fake engine noise, or make the Z a little bit more pleasant to drive.

Cheers!

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