So I'm swapping my head unit out with a Pioneer unit. My car is a 997.1 with Bose. I'm using the MOST HUR 997 interface to retain the factory Bose amplifier. Took my time but finally got it working.

One issue though, the fader control does nothing. All sound for the front channels is sent to the front, rear and sub speakers by the MOST HUR. The rear channels out of the head unit are ignored. Is this normal?

Does anybody have their fader control working with MOST HUR and an aftermarket head unit? If yes, what head unit do you have?

 

From what I have read, you lose control of ability to fade with the MOST HUR adapter. It was recommended in a post to set the fader where you want it with the factory radio prior to removal and installation of the new HU.

 

i had the head unit replaced in my 997.1 with a alpine unit. i lost all sound from the back. Pro shop that did the work took hours to even figure out how to get it to work at all. Not going to bother taking it back to them. Not a big deal in the small cab.

 

I just spoke with Nav-TV's tech support. They make the MOST HUR 997 product. The tech confirmed my findings, no fader control. As a matter of fact only the front left and right RCA's are used. The green and purple RCA's which look like rear connections do nothing. All left side speakers in the car are driven from the FL radio output connected to the Nav-TV device. Same thing for the right side of the car and FR output. This includes the subwoofer. The best you can do is a 2.0 speaker system with static fader emulating a 4.1 speaker setup. This sucks, was expecting a true 4.1 FL/FR/RL/RR/Subwoofer speaker control setup.

If you want to adjust the fader, set it up with the OEM PCM head unit prior to installing the MOST HUR device and new radio. This is similar to the way the volume is initially setup.

There is a separate thread from a board sponsor CAI-Store.com showing how to disconnect the subwoofer from the Bose amp and drive it directly from the head unit. This at least upgrades control from a 2.0 setup to a 2.1 setup. I'm likely going down this route: https://www.6speedonline.com/forums/...formation.html

TL;DR no dynamic fader support keeping the Bose amplifier and MOST fiber optic network, it's a static fader setup only

 

In your settings turn off the rear speakers, they don't drive anything from the radio. If it's not possible then set the fade control to all the way forward. All speakers on the left side are drive from the aftermarket radio's FL output. If there is still no sound in the rear, then the installer likely had the fade set incorrectly with the factory radio prior to installing the new radio. Temporarily reinstall the original factory head unit, setup the fader correctly, then reinstall the new radio.

 

wish I could re-install oem head unit but I sold it on ebay soon after replacing it.

 

This is why I decided _not_ to replace my MOST PCM, and instead went with a Dension Gateway unit to provide USB/iPod/Bluetooth.

In the stock MOST system, all the Fade and other "pre-AMP" functions happen in the Amp, but are controlled by the PCM. You basically lock-in those settings and rip the ***** off, when you remove the PCM. Less than ideal. In order to get full Fader functionality, you need to also replace the Amp/MOST with 5 channel connections.

There are some other functions that the PCM performs also, such as default A/C settings, etc. These too would be unavailable when the PCM is removed. Does anyone have a complete list?

 

This is a BIG PROBLEM for me now, I asked the installer beforehand if this will be a problem and if it will sound bad and they said no, they also did'nt know anything about setting your fader on PCM to 4 before taking out but i did that anyways (I think this is a MYTH as it really did nothing)

Now i feel like most of the sound is from the front, and when i turn up music with bass the front speakers of course crackle- I always liked having more sound from the rear, all that and i am also getting an engine electrical sound whine with RPM when music is turned down ...

spending 2k for this production and totally not happy! I bought the pionner 4201nex and got from delrey customs and they installed it, so not like i went to amateurs ..

Guys stick with your BOSE, thats all i have to say!

 

I had an alpine unit(don't remember series) installed by Custom Sounds in Austin Tx. The sound is excellent but no rear speaker function at all. I had thought about going to Del Rey in CA as I had previously seen a thread where they had replaced the receiver, amps and speakers on someones 911 successfully. However, after reading through this thread I am reluctant to make the drive and spend the money. I can live with the front speakers only since the cab is so small but just hate something that doesn't work as it should.
Wish someone knew for certain a fix for this problem.

 

So i went back today and we discovered there was a wire that wasn't all way in thats why the humm noise with RPM and we reconnected my original PCM and set fader to rear all way to 7 then reconnected unit and now it sounds MUCH MUCH BETTER , good enough that i'm happy with it now- Thank God this was solved!