Belgian_Dude

Did you try amp volume?Saw in your video you have this option, too :-)

YarraMates

Yes, I lowered amp to lowest -15 but it made very small difference. I chatted with @myw and we confirmed the issue is due to my car having Sound Plus option. The signal is being amplified twice; first by new HU, then by OEM amp under passenger seat.
First thing I'll try is use RCA output as it is not amplified. I will have to pull the audio wires from quad lock harness and send them to RCA output. Will report back.
Just surprised that nobody else has come across this issue over the years. Perhaps SPP is a rarer option and not many cars had it.

Belgian_Dude

Thanks for your feedback!
I wonder then what the difference is between SPP and the ASK amp...
Your SPP may amplify all frequencies, whereas the ASK only amplifies the low range?
Although I may be facing a similar issue, albeit at smaller scale, as I too have the white noise audible when nothing is playing and volume is at anything but 0... (And have set all Voice options to 0)

To be continued....

YarraMates

Writing this in hopes to save a lot of troubleshooting for anyone else who is going to use these Android head units with their Sound Package Plus optioned car. I was stumped for a couple of days and surprised that over the years this has not been reported in detail.

EQUIPMENT

2010 Cayman 987.2 with Option 490 (SPP) - Sound Package Plus (9 speakers). CDR30 OEM head unit. NOT BOSE.
Android HU purchased from Owtosin Official Store - Version 13 - 4G Qualcomm Snapdragon 665.
***You do NOT need an optical fiber adapter.
I quickly realized that an optical adapter box was not necessary as there are no optical wires going to the factory HU.

PROBLEM

Significant background noise.
Volume setting 1 is much too loud.
Reducing volume to 0 on OEM CDR30 HU prior to removing it had no effect.
Reducing values in VOICE screen to 0 had no effect (Settings>Car>password 126> Voice)
Reducing AMP output value in OTHER screen to -15 had very little effect (Settings>Car>password 124> Other)

CAUSE
Cars with SPP have an amplifier under the passenger seat. The signal from the Android unit's main "power" wiring loom is already amplified, thus the audio signal is being amplified twice.

SOLUTION
Let the existing Porsche OEM amp power the speakers and send unamplified audio from the new Android head unit. The RCA output on Owtosin unit is not amplified. We just need to isolate the audio wires (Front Right +- ,Front Left +-, Rear Right +-, Rear Left +-) from the main "power" plug on the HU end and connect them to the RCA out plug instead. This is actually quite simple. This method only requires modifying the main "power" wiring loom that came with Android deck.

1. Depin (or cut) audio wires from the "power" plug that goes into the head unit. Refer to a sticker on the HU for colors. For me, these were White/White Black, Green/Green Black, Purple/Purple Black and Grey/Grey Black. So now we have the main quad lock loom that will connect to the OEM harness in the car on one end, and on the other end it will plug into HU for power and canBUS, but with 8 audio wires loose. Now we need to connect those audio wires to the RCA output on the HU.
2. I chose to use the existing RCA female connectors on the audio out loom. I bought 4 RCA male connectors on Amazon - make sure to get ones that split into two wires for easier + and - identification. Then simply match up RCA male connectors with colored wires from the first step. For example, for Front Right, I had grey + wire going to RCA male + and grey/black - wire going to RCA male -. Now we have 8 audio wires from the main harness connected with 4 RCA male wires. I used simple crimping connectors. This was my result:

3. Now just match up your RCA male and female connectors keeping track of speaker corners.
This has completely cleared up my sound issues and allowed me to keep the OEM amp, which I think is better tuned to work with existing speakers. The sound quality is actually amazing and all eq and balance settings on the Android unit are functional, so you can really dial in the audio.

I suppose, a tidier option would have been to bypass the RCA plugs entirely and connect directly to the audio out plug but I wanted to keep this simple and reversible.
Owtosin should just make a different harness for people with SPP. It really is such a simple mod for them to make. Perhaps @myw can advise his contact there on this.

The absolutely best solution would be if these units can simply turn off the built-in amp via software, perhaps in future versions.

myw

What a writeup! Thank you.

Now I have to see if this also applies to the .1 pcm 2.1 SPP cars.

myw

Bingo!

Does your car have SPP?

Belgian_Dude

Yes I do, in the form of the AKS package: amplifier in the drunk.
It only amps the bass drivers, not the midrange or tweeters.
Will do some testing later today, should be easy enough by pulling the amplifier's separate fuse :-)

Will report back!

Kudos to @YarraMates for the brilliant debugging and writeup!

T0m

I got a 997.1 gt3 with the Sound system A.S.K. (490 option code)



do i just get this one or do i need the fiber module ?

Belgian_Dude

No fiber needed :-) that's only for BOSE

YarraMates

To be absolutely sure just pull out your current HU and see if there are any optical lines going into it.

Belgian_Dude

Trust but verify, you're right ;-)
Be mindful though, as there may/will be fiber optic there to connect the nav DVD player in the frunk, which is no longer needed and will not work through a most adaptor anyway.

My logic was to look at the ASK amp and verify no fiber optic is terminated there.

Belgian_Dude

Not due to double amplification, visibly, the white noise is identical with or without the amp powered...

Have ordered a ground isolator, will wire that in and report back

myw

if your car has no bose speaker labels on the doors, then you wont need the MOST converter.

myw

Has this been ordered?

I'm trying to 100% confirm if a modified high->low iso Harness needs to offered as an optional addOn for the .1 SPP cars as it has been confirmed for the .2 cars.

Feel free to PM me.

myw

the non bose cars use ask amp. This isnt the same however as soundPackagePlus, soundPackagePlus has YET another amp.