blyent

I have the 2020 High Country with Bose system. This is what I've done. My initial plan was just to add a subwoofer. So I bought a T-harness from LLJ Customs. I had a local box builder build me a sealed box for a single sub 12" sub. I had him wrap it in black vinyl to match the black leather seats. I put in a JL Audio 12w3 in the box. I powered the sub with a Rockford Fosgate Prime R500XD1 mono amp. I paid $100 for the box, $150 for the sub (used), and $148 for the amp on Amazon. I wired it up and it was everything I wanted for bass. However, there are absolutely no tweets in the factory system. Their is a 2.75" midrange in the dash and 6x9 mid bass speakers in the front doors. The sound is very underwhelming. So, I set out to upgrade the front speakers. I have some old Boston Acoustics Pro series 3 way compenent speakers (6.5" mid bass, 4.5" mid range, ~1.5" tweeter). These speakers I've had a long time and they sound amazing. Anyway the 4.5" wouldn't fit in the dash without some major modifications so I bought some kenwoods off of crutchfield that would fit and thought I'd just use that one instead of the 4.5" mid range from the boston set. I bought an Audio Control D-4.800 4 channel amp with dsp integrated to power the new speakers. I thought I could purchase the 6 channel T harness from LLJ Customs for this for about $50. However, after researching this, the T harness is not what I needed. I would need the Loop back harness that costs roughly $300. In continuing with the research I found that alot of people had issues with the door chimes being super loud after adding an amp and replacing the front speakers. I didn't want that. So, I started playing around with the system. I put a pair of coaxial speakers in the door powered by the bose amp. That was god awful. Apparently the only signal it sends to the door speakers in mid bass. Nothing else came out of the coaxial speakers. So then I used a posi tap connector to grab the signal from the dash speakers. Out of the coaxial speakers came nothing but tweeters. So I knew I could get tweeter and mid range from the dash speakers. I then took the tweeters from the boston seperates and hooked them up to the posi taps ( not directly though, I still had the signal going through the passive crossover that came with the bostons). If your able to follow I've got the factory 6x9's in the front door, I've got kenwood 2.75" mid range in the dash, and I've got boston tweeters tapped into the line going to the kenwoods. It actually sounded really good. Not as good as if the full set of Bostons were powered by an aftermarket amp but surprisingly good. After hearing all of the issues with loud door chimes and also the navtv unit. I'm not sure its worth the effort of going with an aftermarket amp for the the front speakers. I'd definetely recommend trying out what I did on your truck and seeing if you like that. The LLJ Customs 2 channel T harness for $35 plus shipping is what I ordered. I didn't add an LOC or anything just used the high level input to the amp. For cost comparison this is what I spent. Custom box for 12" sub - $100 JL Audio 12w3 used - $150 Rockford Fosgate Prime 500w mono amp - $148 Kenwood Excelon KFC-X2C 2.75" dash speakers - $70 Amp Wiring Kit off Amazon - $35 posi taps from Amazon - $7 speaker wire from walmart - $13 I already had the Boston Tweeters and passive crossover.

Did you keep the bose speakers and just added tweets? So basically no longer using the bose amp and using the JL amp to power everything including the new tweeters? I'm in the process of putting in jl audio sub under the back seat of my 2020 High Country. The Bose mids sounds ok, but their is basically no tweeters. I want to add some tweeters to the mix. I didn't want to add an aftermarket amp for the mids and tweets but I guess in order to add tweeters I will have to.

This may be a late response. However, look at LLJ Customs. They have several wiring harnesses that are plug and play. I just ordered one. https://lljcustoms.com/store/ols/categories/gm-vehicles