On the topic of getting the throttle controller apps working on the native HU, I got this back from RaceChip



I assume there is some restriction in getting your apps in the Play store "licensed" to display when the car is moving - that may well be a policy that Google has, but these Android HUs are tablets and in theory should work the same way as a phone. And I don't understand quite what this has to do with the conttroller hardware not showing up as a bluetooth device in the Chstek

In any case, I can't see a way to fix this, but it's easy to change throttle modes with the phone app and in any case Sport mode is more than sharp enough for me

 

Where's the support contact info?

 

Where did you look?

 

Hey all, long time lurker first time poster, read this entire thread last night and decided to finally upgrade the radio on my 2015 GT3 with CDR31 + SPP to the CHSTEK unit . The vendor is suggesting I need a decoder box for fiber optic, is that accurate for SPP? From what I understood, only the BOSE stereos needed it but maybe I'm wrong.

 

Welcome to the thread and great choice with your upgrade, you will really enjoy it!

You are 100% correct, you do not need a decoder box unless you have Bose or Burmeister. With the standard SPP (which is what I have) you do not need any additional hardware.

The only thing to note, as you will have seen in this thread, is that with SPP the sound is output via the quadlock, which has the advantage of firing up all 4 speakers (unlike Bose), however it is an amplified output that then gets fed into the SPP amp. This double amplification creates a soft hiss when no audio is playing and it makes the volume control a bit sensitive, but you can mitigate this by going into the settings and playing around with some of the output levels. I think you'll be amazed how much better your music sounds as the audio hardware is greatly improved over the old PCM/CDR.

Keep us updated and we'll help with any installation and configuration issues - and make sure you read the guide which is linked in my signature below!

 

So there's no way for the Bose system to utilize the rear speakers? What options do we have to use those?

 

My understanding is that no aftermarkeet Android HUs support rear speaker outputs. This is because the MOST/fibre adapter box only supports the front 2 channels

I think the best you can do is use the fader control to send some of your front channel output to the rears. @ZedZed can probably give you a better answer as I don't have Bose!

 

It is a Google policy, but these HUs have a workaround for it, which is why you can watch Netflix etc while the car is moving. But that doesn't really explain this issue, as you say, because the problem is Bluetooth, not the driving thing. After all, lots of apps can display while the car is moving - er, all of them in fact! It's video that is restricted, for obvious reasons. So there's no difference really between a throttle response app being called up while the car is moving than there is with, say, Torque Pro etc, and that works fine. There may be a language barrier issue and they can't really explain it, but I suspect you are right - the problem is with Bluetooth. There must be a valid reason though, since both your Racechip and my Pedal Commander are in the same boat.

I haven't worried about it - I haven't once felt the need to change mine since I got it dialled in. Mrs Zed has played around more with hers, but even she's settled on one of the more aggressive modes now..Personally., I'd dial it back a bit - every time I drive her car I spin the back wheels until I get used to the setting she uses, but she must have a more modulated right foot than me The good thing is, there's a setting for everyone. And they all make an astonishing difference to the 'feel' of the car,

 

As Andy says, the problem is that the MOST box only has two channels. You can work around it by messing with the various fader settings in the DSP section of Settings (that is where it is in the Erisin - it will be, I think, similar in the CHSTEK. In my Panamera I have managed to get a pretty good balance between front and rear. In a big car like the Panamera (or Macan etc) I think it is more important than in a 2-seater.

Of course, all that can be achieved is sending a copy of the FL and FR to the rear speakers - there is no 'surround sound', other than the horrible 'concert hall' pseudo-surround effects that (I think) the PCM offered. For true discrete sound to the rear speakers, you would need a true multichannel amplifier and something like Dolby 5.1 as a source. I don't know of any car head units that can process true surround sound, using a discrete multichannel source signal, and in any event, there are no m/ch content sources for cars either AFAIK (Blu-ray discs if your car has a Bluray player? But ours don't have any sort of disc player once the HU is installed), So whatever you do, you will be copying the two front channels to the rear, since that is all your MOST box can do. In my wife's non-Bose car, there is no issue with this, as the quadlock has 4 speaker outlets as standard,

If you go the Guide and look at Page 28, we covered the way I did it in the Panamera. Give that a try and you should at least get sound from the rear speakers.

 

I'm jumping back in here on the topic of rear speakers for a Bose car. Is there no way to replicate the The front signal into the back signal? Maybe splitting the signal and utilizing a second MOST box? (I'm just spitballing here). Fader controls don't really do much.

I'm not looking for quality surround sound. I'm looking for more volume with the top down.

 

You are right that the fader won't give you more volume. The problem is that as the fader adds sound to the rear speakers, it subtracts sound from the fronts (in our setups). The problem with splitting the signal comes down to the optical connection the car uses in a BOSE system. If we could somehow split the optical signal into two connectors, your idea might be feasible. It is possible to split an optical signal using a designated splitter adapter, but AFAIK all of the available splitters are one-in-two-out TOSLINK connectors like this:


This is no good for the optical connector used by Porsche. Even if it was, it doesn't get us anywhere because we might be able to split the input, but we are stuck with the single output (that orange fibre cable that disappears into the car's dash). I have never looked closely at the amplifier in my BOSE-equipped car, but it may, theoretically, be possible to tap the front speaker wires and add the rear speaker wires to them. This would just add a couple more speakers (RR and RL) to the amp's FR and FL outputs. However, doing this will change the impedance load of the speakers seen by the amplifier. Since the designers of the amplifier didn't spec for this, then damage to the amplifier could be caused, or distortion of the output or any number of other undesirable consequences. It might work, or it might not - no way of knowing without a detailed spec of the amp or just trial and error, There might be a way of adding a booster amp to serve the rear speakers, but having never seen the amp in my car I can't say for sure.

The basic problem is that the aftermarket HUs only output two channels into a BOSE system via the required MOST adapter box. I did once see a 4 channel MOST box being sold out of Russia, but no amount of subsequent googling has found it again, and it may not even have been genuine anyway. I have no idea how Porsche accomplished the front and rear BOSE setup - if anyone knows that, it may well give us a clue as to how we could replicate it.

You might get some joy from a dedicated car stereo installation outlet - they should at least understand how Porsche-Bose systems work and may have a workaround (at some cost no doubt). Alternatively, they could replace the BOSE amplifier and optical setup with a conventional (non-optical) setup (similar to what is in our Cayman and Andy's 911), retaining the BOS|E speakers. Again, at some cost. Might be worth an initial no-cost chat with the best local car audio installer to see what they think? Personally, and that's all it is - my opinion - I don't think that realistically there is much actual audio difference between BOSE and non-BOSE when you consider the dreadful acoustic environment of a car interior, plus the huge amount of external ambient noise. If I was speccing a new car, I (personally) would not pay extra for BOSE. I suspect it is just a great marketing concept by Porsche to gain added-value profits at not much cost to them). I respect the views of those who disagree with that.

 

I suspect you are correct, that you need to go analog to make four channels. And even then it'll be two channels split. Got to replace the optical setup. I'm not going to bother, most likely. A converter I would do, changing an amplifier, I don't think it's worth it because we're talking about a convertible. Talk about bad acoustics. I'm just looking for more volume on the highway.

 

Yes, agree entirely. The rewards aren't worth the hassle and the cost, IMO. I've never been a big fan of convertibles (probably because UK weather is generally awful) but Mrs Zed has had several, and I have always found that the ambient noise easily overwhelms even a powerful sound system, once the car is moving at 30 mph plus. And I'd never dream of playing loud music with the top down in a town or city, so for me, sound in a convertible soon becomes a non-issue. I'd still like a fix though for the rear speakers, just because . . .

 

It's funny, in all my toy cars, I don't even turn on the stereo! I just enjoy listening to the cars. I also prefer coupes, but wanted a Boxster for our vacation home. And Mrs. AdamIsAdam loves convertibles. But ever since getting this one, I find that I always want tunes cranking! Takes me back 40 years or so. lol.

 

If you really want a rear speaker option, you could use the RCA outputs on the head unit and send it to a small 2 channel amp that just controls the rear speakers. If you got a small enough one, you could fit it under the right-hand seat where the Bose amp is located. There is a little room next to that, and all the speaker wires are there to tap into the rears. You would need to get one that you could adjust the gains so you could get the volume level right compared to the other speakers.
Another option would be to replace the mids in the doors and the rears with 4 ohm speakers and wire them together in parallel so the amp sees 2 ohms.
I have a Cayman, so I don't miss having rear speakers, but I can see the appeal to having them in the 991.

If I were to start over, I would probably buy the HU without the MOST adapter and just replaced the amplifier and hooked it up via the RCA outs. Then eventually replace all the speakers. This still wouldn't gain a fader since it only has 2-way RCA cables, but you could easily power the rear speakers if you wanted to. As it is, I've added sound deadening to the doors, which helps the sound quite a bit. I also have new tweeters that I am installing in the dash this weekend. This is basically the Musicar stage 1 package, but I am using my own components. Everything that I have read says that these are the biggest bang for the buck changes you can make on the 981/991.