Ah. Thanks For the clarification.
I've been harvesting the internet to figure out why the HK DSP has a CANBUS connection but I get nothing.
Actually, I can't even see it in your pictures.
Your pictures and pin out guide show 12 wires + 2X pwr & gnd. That tells me you have 6 sets of inputs as I'd suspect they kept inputs on one clip and outputs on another clip.
Unless there's a third clip plugged into the HK, there can't be a CANBUS connection, just like the Rockford Fosgate package.
Are there more clips and can I see it?
RF instructions:https://www.subaru.ca/content/7907/...pgrade Kit_2017 Impreza _11_17_16_ENG.pdf.pdf
That said; There is no special HK output on the headunit output. Each of the four Harman models that Subaru uses has the exact same outputs.
I believe you can remove the device and revert back to the standard speaker lines; using the HK harness wires or running new ones from behind the radio via splice or breakout.
The HK would have to plug into the standard Subaru harness somewhere behind the radio.
The question becomes where that connector is because the headunit's output only has 4 channels yet you have 6 HK inputs
That means it's somewhere after, or at, the place where the harness does a parallel split to separate the door and dash speakers.
Of course, if there's another clip with 8 wires, the 12 wire clip would be your outputs to the 6 speakers plus power/gnd.
FYSA: I could be wrong for the Base model and would have to check again but the only difference is that it doesn't have a XM input.
The functionality differences between the models are: Base hasn't got a CD player. The High is a Mid with navigation. Otherwise, they share all internal components and connectors (except the Base as per above). For reference, the 2019's G31 models are BE2831 (Base), BE2832 (Base+), BE2833 (Mid) and BE2834 (High).
The G3's are similar to the 31s but while the Mid and High are separated by navigation only, the 6.5"'s internals are not very similar.
I still think you can use the HK harness to your advantage and I love that it provides the option of running a 6 channel amp (to hell with the dash capacitors) or a 4 channel amp capable of a parallel 2Ω.
As said, I don't have the HK (thankfully) but you can easily test my assumption: Unplug the HK and see if anything funky happens. If not, connect a speaker to the exposed harness terminals.
If it works, your solid.
If I'm wrong, I'll be happy to eat it. (It won't be the first time; eh, MiniSQ?)