[Greg_2086]

Again thanks to all involved for taking the time to determine how to integrate the 2020 Harman head unit with the trunk mounted door speaker amplifier. And thanks to FR-S2GT86 for this extensive DIY write-up. Having finished wiring up the inexpensive version above (FR-S2GT86 post #2), I wanted to chime in and agree with the others that there is a noticeable difference in both sound quality and loudness. Quality is less muddy presumably due to reducing overlapping/competing frequencies of the door and dash speakers and no longer requiring the head unit to drive a 1 ohm load for the front channels. Loudness is also increased at a given volume setting likely due to higher power of the amplifier. For reference, my previous equalizer settings were bass +3, mid +1, and treble 0 and my new settings are bass 0, mid 0, and treble 0. Edit: Now that I have driven the car a few times over the last week, I have also noticed the vocals soundstage is much improved and more naturally in front of you.

I wanted to share some pictures of how I wired (more can be seen in my build thread, see signature). I de-pinned the amplifier turn-on (terminal 9) from the 10-pin connector. To connect this female terminal to the antenna turn-on, I used Toyota male repair terminal part number 82998-12330 and Posi-Tap #502. This provides for a secure yet easy to revert back connection.