EDITED MY ORIGINAL POST WITH THE INFORMATION THAT I HAVE FOUND AND CONFIRMED (BOLD LETTERS)

 

 

 

 

Harman Kardon and Subaru suck!!! This is the nightmare so far....tried to wire the sub output direct to a subwoofer and there was some output but it was was not enough (enough for the original woofer but not an aftermaket sub-Kicker 10 inch CS series) but that was a total failure, Im guessing that the amp is literally the same wattage to the sub as it is to the rest of the speakers (70x6?).

Then, as plan B, I got an Audio Control LC2i Pro and a 1500 watt amp to go with my subs using the same sub outputs to the LC2i which was set using a voltmeter to match the amp inputs (6v) and still weak bass. The only way I can get any kind of real output is to set the gain on the amp to 90% (guessing, its a knob, almost max).

Now the plan is to purchase one of those harnesses from autoharnesshaus and try the front speaker outs to the inputs of the LC2i (I'm guessing sub outputs from stock system are low/fd up by kardon processing, so im gonna try the fronts or rears to try to get a better signal). I will update as soon as I get more info.

 

The harness works great, that's exactly the route I took. I have a write up on here for it if you're interested. It's not the harmon Kardon system but same thing for adding an amp and subs. Kicker sells a tiny adapter that will convert the signal to rca jacks. My last car I used the dsp lc2i, but wanted to try this little guy out. It actually works really good and was only $20

 

Does anyone know which outputs I should use (ON THE HK SYSTEM, nothing that forums and websites have stated for the base system match the HK system and the HK system processes the signal furhter making this a PITA), the fronts or the rears (sub outs seem to be low, have my lc2i and amp gains over driving my woofers because if I set everything up using a multi meter, output is almost non existant)?

 

Got my harness from Autoharnesshaus and am using the front outputs...output is substantially better. So for anyone else doing this, forget about the sub speaker outputs and go with the fronts. Only problem now is my subs are drowning out my front stage so I'll need to start fighting that.

 

Glad to hear it worked out for ya!

 

bought some infinity reference coax for the 3.5 & 6x9 fronts and now my music goes out when I raise volume to 28 (~76% of total volume) and will not come back on until car has been off for hours. I think it may be the 3ohm speaker rating (real 4 ohm according to them). Any thoughts?

 

This Harman Kardon systems is such a PITA...the DCM is showing an error (radio diag hold <> temp control and press tune knob 6x), I don't know anything more but based on reading I think it is related to the fact that I have tapped the front signal from the harness for the LC2i, installed 3 ohm speakers with a bass blocker all combining to mess with DCM...

if this is the case can simply connect a 1 ohm 25w resistor at the autoharnesshouse harness to show the proper load for the amp/dcm (as I understand it the DCM powers the 3.5s)? And if so which wires do I need to tap?

Thanks in advance for any suggestions?

 

no real suggestions, but want to do the same to my '23 and have been researching. The only thing I can add, is I ordered Crutchfield's installation notes for the WRX w/HK audio, and they included the following note:

"In vehicles equipped with the Harman Kardon audio system, replacing the high-impedance factory speaker with a 4-ohm speaker will result in higher volume levels and can cause the factory radio or amplifier to overheat."

This has caused me some pause - I've always just put 4ohm replacements in and they were good. Worried that might not be the case for the HK system.

 

OP, it's an older thread, but THANK YOU. I've been in the car audio game since the late 80's and I went with a 23 Limited because upgrading factory audio has gotten so difficult that I'm throwing in the towel. I don't love the HK system, but it'll do. I must say, I'm impressed with the seamless infinite baffle subwoofer set up.

 

I just installed a kicker cxa800 amp and two 12” subs in my son’s 2023 wrx today. The amp has a hi/lo rca signal input built into it up to 400 watts input, so we tapped into the speaker wires going to the sub on the rear deck. We gained access to the sub by removing a push pin on both sides of the deck and one of the rear side panels needed popped off up by the window and it we pulled it right up just enough. Can’t say for everyone but for his car there were 4 wires going into the sub, red & darker blue are the positive, light blue and orangish color were negative. Also has some kind of auto on feature, not sure what it is exactly, but long story short there was no need for a remote wire. The amp turns on when it gets a signal and turns off after a minute or so of no signal. Just ran the ground, and for anyone having issues with how to run the positive, we took out the wheel liner and if you reach up you’ll feel an opening, on the inside of the car you can reach to that area and pull a rubber plug out, punch a hole in plug, then feed wire up through fire wall, out the hole in wheel well, and into engine bay. I have the same setup in my truck for 2years now with no issues. I’m also neither a Subaru guy or a car a/v guy, I just know how to install amps, but hope this helps somebody.

 

Hey I have recently purchased a setup very similar to your son, I was just wondering how you connected the wires to the RCA input on the amp?

 

Hi. I have found time and disassembly this guy.
Big IC it's Renessas Arm mcu. Next is audio codec from Circuit Logic, then Harman specific DSP.
Under blue paste, something from ST, most likely it's FDA802S, that give us 2x28 W /4 Ω at 14 V, 1 kHz THD = 10%.