EDIT 11/10/2015: This audio noise has been fixed by a Garmin software update.
After nearly a year with the RT, there is one thing that has bugged me and, thought not "fixed" strictly speaking, the issue has been circumvented until BMW engineers get around to figuring it out. For those interested, here's the story.
There is electronic noise that comes through my 2014 RT's audio system. Imagine what a digital sewing machine might sound like with a continuous, rapid, repeating pulse. It's audible when the bike’s audio system is played while the BMW Navigator 5 GPS is installed on the bike's GPS cradle.
The sound is audible when the bike’s audio system is on and set to FM, SAT, AUX or USB. It’s easiest to hear in AUX since I have nothing attached to that audio input on my bike, but it’s also audible on USB which I do use, and on radio when there is a break, such as occurs briefly between segments. It is harder to hear when a musical composition is loud but unmistakable during quiet passages and between tracks.
The sound is audible with a BMW Communication System Bluetooth (through helmet speakers...I sold that system because the sound quality was lousy), with a Sena 20S Bluetooth (through helmet speakers or wired earbuds, which have superior sound quality), and through the bike's OEM speakers mounted in the dash (which I never use).
The sound stops when GPS notifications like "Turn left on Mountain Road" interrupt the music, but the sound returns as soon as the music returns. (Note that the GPS is paired via Bluetooth to the helmet, not to the bike's audio system.)
Turn the audio system off (there's a push button on the left fairing panel) and the sound goes away.
The sound gets louder in proportion to increases in volume of audio being played. That is, turn up the volume and the sound gets louder.
The sound appears when the key is on, whether or not the motor is running. The sound does not change in volume or frequency when the motor speeds up or slows down. That suggests it's not ignition related.
The sound appears whether or not the paired phone is connected via Bluetooth. The sound appears if the paired phone is powered on or off.
Remove the Nav 5 from the cradle and the sound stops. Replace the Nav 5 and the sound returns. I placed a friend’s Garmin zumo 665 (same form factor as a Nav 5) on the cradle and the sound was not there. I placed another friend’s BMW Navigator 4 (from his K1600GT) on the cradle and the sound was not there.
I cleaned the contacts on the Nav 5 and the cradle and gave them a thin coating of dielectric grease. The sound was still there.
I attempted to rule out interference from other electronic items. I removed the micro SD card from the Nav 5 and replaced it in the cradle. The sound was still there. I tried USB sticks from different manufacturers and the sound was still there. I have a Heatroller temperature controller. Removing that from the bike made no change and the sound was still there. I have a battery powered Gen3 Spot Locator. The sound appears whether it is powered on or off. It’s not the LED Clearwater Lights. There’s no difference in the sound when the Clearwater lights are adjusted to different dim settings. There’s no difference in the sound when the Clearwater CANopener module is disconnected from the CANbus network and the harness fuse is removed, leaving the bike in factory condition as far as electronics go.
These results suggest that I have either a bad Nav 5 or bad a cradle on the bike. At MaxBMW we tried another new-from-the-box Nav5 and the sound was still there. Then MaxBMW replaced the bike's GPS cradle with a new one and the sound was still there.
MaxBMW has been after BMW for a fix for months, but BMW hasn't come up with anything. It's in their system, it's just not getting addressed. I had been searching RT forums for a solution but it was brought to my attention that the audio system in the K1600GT/L is pretty much the same as in the RT. ("Hmmmm," said Bones.) I searched the GT forums and what do you know? The audio interference has been an issue for the K16 crowd since before the RT ever arrived in the US. BMW hasn't solved the problem yet, but a member of the K1600forum found a work-around. It doesn't solve whatever the underlying problem is, but it does eliminate the noise.
It's all here:
http://www.k1600forum.com/forum/bmw-k1600-bluetooth-audio/49370-strange-noise-amp-2.html See especially post 13.
The work-around involves simply unplugging the GPS audio feed where it goes into the audio amplifier, under the pillion seat. Just like that, the noise is gone. So something related to sending GPS audio via hardwire to the bike's audio system is in need of shielding or reengineering or something. Also could be software related on the GPS. Since I paired my Sena 20S to the GPS, I get turn-by-turn GPS audio via Bluetooth anyway so I don't need the hardwired GPS audio and pulling that plug stops the noise. That said, there is now no GPS audio to the speakers, should I decide to use them. I haven't used them in a year except to make sure they worked when I brought home the bike and a couple times in the garage while trying to diagnose the noise issue.
So I'm not satisfied that the bike's audio system works properly, but thanks to the K1600 guys (especially member ABQ from Albuquerque) I've stopped the annoying noise. BMW knows about it, but when they actually get around to fix is anyone's guess.
I would be pretty happy!
