Subwoofer swapped
Used the Soonish kit, plus their recommended sub* and amp combo. Their install video was priceless, walks you through every detail. For the price it’s absolutely worth it - I’d say the sound is 40% better. Rivian door speakers no longer have to try and makes much bass, and the subwoofer provides a clean, deep, even bass floor. I’m not looking for thump, just confident clean bass. Soundstage and everything else still kinda stinks…
*they recommend the 4ohm sub. I somehow got the 2ohm. Either way, the amp is stable at 2ohms and actually matches the RMS of the subwoofer at 300watts.
Took about 5 hours, I went very slow and deliberate, especially popping off trim. Plus a 30 min stop to read up on ohms and watts and make sure I was good with the 2ohm vs 4ohm. Conclusion: 100% good.
Tips and tricks:
Empty your sub trunk so you can sit on the edge. Way more room to work.
The rear passenger seat bolts take some serious muscle to loosen. And there’s a bolt hidden behind the air ducting that’s a PIA to get to. It’s in the video.
The Keyloc system says to flatten your EQ when you train it. I chose to reduce the last 2 bass sliders about 1/3, so the Rivian speakers aren’t trying too hard and the sub can handle those hz
Reset the car after install. Mine wouldn’t go into deep sleep, so the amp was drawing power continuously. Once the car sleeps the amp turns itself off. Thanks to Soonish for helping me troubleshoot!