i don't know why that isn't more of a widely performed option. i want heated mirrors so bad, especially on those frosty mornings.

 

While shopping, I got the feeling that the reason why heated mirrors are not available on the LX (even with the Sport option) was to encourage customers to step-up to the EX

I spoke with a Honda rep at their HQ in San Francisco and mentioned that (in my opinion) heated mirrors should be standard on all models at any trim level for safety reasons. Honda thanked me for the suggestion and said that they would take it into consideration as a future prospect

All in all, though... I'm very happy with my Sport

 

a long break for many reasons - mostly other projects. Since I have the second HU, i have a clean source. But a little motivation got me back into it.

Step 1 is to add wire to the Audio Input pins on the HU amplifier IC. This is the easiest place to get a low-distortion signal before the internal amplifier and this signal should already be passed through pre-amplifiers. Doing so required 30awg "wire wrapping wire" (OK Industries R-30W-0050) and a 0.03 in. soldering tip.

An LED magnifying lamp helps as well, and some of the pics are through the lens.

In all, I tapped 7 places.
Pin 14: FL in (left front audio - unbalanced)
Pin 15: FR in (right front audio - unbalanced)
Pin 12: RL in (left rear audio - unbalanced)
Pin 11: RR in (right rear audio - unbalanced)
Pin 13: AGND (audio signal ground)
Pin 25: B REM (remote turn-on)
Pin 22: MUTE (suspected telephone mute)

odd-numbered pins are in the front and easier to access (you don't have to remove the board). even-numbered pins are in the back and you need to remove the board to get your soldering iron in there. Removing the IC isn't necessary. This took about an hour start to finish and i did reference my instructions at the start of this thread for the order in which to disassemble.

I may have a concern with running parallel loads on the pre-amp on the board, but the opamps should be fully capable of supplying twice as much current given how little current feeds an input stage (typically 10,000 ohms).

Next steps (tomorrow evening) include adding small heat shrink up to the connections for protection. Then I'll connect the wires to some RCA pigtails (pulled from an older Alpine head unit that was for parts). And the remote and mute will need a connector added. i can cut into the top cover to notch for the RCA pigtails.

all wires connected


front pins




rear pins




RCA to be added



once I have RCA outputs I can run them directly into my 9887 AUX input and also RTA the output (what we really are interested in). I suspect the output will be fixed (non-varying) because most amplifier IC's have a volume input.

 

Just tapping the pins wasn't consistent and the HU circuitry didn't like the parallel connections. It was randomly muting output. So I removed the IC to also get a confirmation of the chip used.



This is the actual IC


I removed the IC pins and decided to solder the RCA stranded wires directly to the board




I changed the location of the RCA jacks which fit much better





works great. I didn't get the channel assignments correct. This is the channel assignment
IN1 = Front Right
IN2 = Front Left
IN3 = Rear Left
IN4 = Rear Right

This surprises me because the circuit layout wasn't symmetric, was completely different than the similar IC I suspected, and i expected an attenuated rear with the front channels having the parallel inputs as seen on the board.

The good news is that both front and rear outputs sound the same. I observed bass roll-off in the output compared to my 9887 but it sounded MUCH better than the speaker outputs. Volume 39 of 40 had no clipping and sounded great - a signal level that matched the AUX input on my HU.

 

RTA testing completed. Front matches Rear in frequency response but not in level. Front is louder (as we all knew) by 8dB.

FRONT


REAR



Front (same as above, different scale)


Compare to the RTA I did on the speaker outputs





Looks like the roll-off is the same and certainly ahead of the factory amp. But this is able to be managed and with ultra-low distortion, i think a standard bass restoration interface or processor should be fine. Especially a processor with an auto-EQ CD that measures the factory output. Regardless of this bypass or high-level inputs, the advantage here is eliminating the HU distortion.

 

Before I removed the amplifier IC, I did some bench testing with a test CD that contained pink noise, 500Hz tone, 40Hz tone, and 20Hz tone. Tones were generated in Goldwave and full signal strength.

I had a speaker connected to the output while taking some readings at low volume, and both worked. Adding the scope didn't generate noise. Doesn't matter now that the amplifier IC is gone, but my original plan was just to tap the pins and not remove the entire IC.

The bass roll-off still exists, but we have ZERO clipping up till 99% volume. These measurements are at the RCA jacks I installed. Also, the HU volume control worked, a good thing for those wanting to use the stock HU by itself.

500Hz tone, 39/40 volume, 2V P-P (0.5V/div)


40Hz tone, 39/40 volume, 0.5V P-P (0.2V/div)


20Hz tone, 39/40 volume, 0.16V P-P (20mV/div)


I also measured pink noise at full volume, 1V P-P average with 2V P-P peaks

 

Working on the H800 installation, i decided to drop the entire headliner and deaden and stuff it. might as well.





this much fit in the rear half of the roof cavities






headliner has some plastic molds that will get foam covering. you can see factory sound absorption pillows (used everywhere)

 

it's a large piece to manage solo, but it was firm enough to stay one piece and not fold.


next up:




brain will be in the rear driver corner, with a beauty panel.

 

Got a lot accomplished in a weekend. I pulled the CDA-9887 and removed previous factory integration. I ran new wiring for the Alpine PXA-H800 and RUX-C800 and paired it with an Alpine DVA-9861. Fiber optic, Ai-Net, USB, Mic, and power ran to the back, down the middle. Factory radio front and rear RCA outputs (custom) to the H800 AUX1 and AUX2 RCA inputs.

Some cool things about this include the ability to retain fader control at the factory radio when using the factory radio as the source. I made a video demonstrating the functionality.
https://www.youtube.com/watch?v=oxirnpWzRP8 Around 1:30am i decided to tackle the C800 mounting. I modified the sunglass holder to house the controller while retaining the function of the holder. This allows the controller to hide away and is probably the coolest feature so far.







the H800 brain is located at the passenger rear and a beauty panel will be made to hide cabling. I'll also make a panel to cover the amps and caps (all with windows to show the components). I'm trying an Alpine 3522S for running rears (custom located in the rear seats). I have some extra cabling here and there for flexibility









a few photos of the wire routing, everything is in split loom. ties or aluminum foil tape at regular intervals as needed. all factory panels fit perfectly.

 

Ran an RTA prior to any EQ or tuning effort. Consider it a baseline. Mic in front of my face. Used a Casella CEL-633C.

This compares the factory HU as a source vs. The 9861 as the source. Factory bass roll-off is seen. There is a 20Hz subsonic filter.


This compares two different volume levels with the 9861.



Made some beauty panels.

And one for the amp rack