Bluetooth Audio (Music) Distortion

[Brad_H]

Greetings,

 

I've been experimenting with the on-board bluetooth (BT) for satellite and broadcast FM music from the BMW system to my headset. I first tried a general purpose BT receiver and earbuds; it worked OK until I ran the bike at which time I got all kinds of interference. So,I tried my Sena 20S, a generally well respected BT receiver made for the electrically noisy environment of a motorcycle. It works great for broadcast FM and satellite with the bike shut off, but has pronounced distortion (sort of like serious intermod. for any engineers or Hams) when I'm running the bike. I have more experiments to isolate the problem: is it the BMW radio receivers or the BT transmitter picking up the noise?

 

Has anyone else noted this issue with music from the BMW system (not your ipod etc.)? I'm not talking audiophile stuff here; this is obvious distortion.

 

Thanks,

Brad

[realshelby]

I am running the new Sena 10S and occasionally use the bluetooth to helmet speakers through the Sena for FM and USB from the BMW system. I have never noticed any distortion, or anything like an electrical noise with the signal. I do NOT have the keyless ignition or auto locking, in case that might be a source of the noise.

[narcosis]

My experience mirrors your Brad. I'm using the N-Com B4 PLUS and pick up interference with the bike running, more so with weaker stations of course. I think the problem lies primarily with the bike's audio system as I don't notice any interference when I just use the B4's FM receiver and turn the bike's audio off.

 

Ken

[Brad_H]

No keyless here either. Thanks for your data-point.

[Brad_H]

Thanks Ken. I think it helps to have these experiences from other users before I go too deep down the investigative path

 

[hopz]

I use the Sena SMH-10 to hear all audio from the bike... including ta jump drive plugged into the right hand box.

 

While the audio is not living room clear I find the sound quality quite acceptable.

 

You mileage may vary...

[HuskerMark]

I too use the Sena 20s. I'm a musician so picky about sound. In my experience the satellite is unlistenable; fm radio can be fair; and flash drive can be decent-good. Found it to be very important to adjust e/q - I have bass at minus 6 and treble at zero. You'll never get good bass, the goal is to get the midrange as rich / full as possible. Good luck!

[rcklindave]

I agree Bluetooth is marginal sound at best I take my audio directly from the amplifier, and play it through custom fitted ear buds, and only listen to lossless audio, and it does sound very good.

 

Dave

[HuskerMark]

Do you mean a wired setup? I have some custom-mold earbuds I might try at some point to see if they make a big enough difference to make it worth the small additional hassle (over built in helmet speakers). Still through Sena Bluetooth so not sure how big a sound dif it would make

[Lucky Dave]

I have a Sena 20s paired up to 2014RT. It sounds like dog $hit. Serius sounds like rotten dog $shit left in the sun.

[Kitsap]

I have the same experience as HOPZ. It's a non issue with my 2014.

 

 

[Brad_H]

I isolated the problem to the BT transmitter on the bike using hints from the K1600 forums. Apparently, at least some of the systems pick up on-bike noise and inter-modulate it with the audio. Speakers work fine as does some selective audio over the BT. Basically, it is good enough for Nav directions and phone (I use neither) on my bike, so I'm just going to use my phone linked to my Sena 20s with earbuds; That combination works as good as it's going to get IMO. Sena give very usable FM broadcast and my phone gives satisfactory mp3 performance. IME, there is no point in using my lossless (FLAC) files as the wind noise obviates any perceptible difference between the lossless and mp3. YMMV

 

Thanks for your inputs,

Brad

[MotoBones]

I had a BMW Comm system originally and was very disappointed in sound quality through in-helmet speakers. Replaced it with a 20S and found the in-helmet speakers to be an improvement but still not all that great. My solution is to plug in a decent set of Klipsch earbuds into the audio out jack on the 20S. It's there for a reason! Sound quality for flash drive playback (pretty much all I use) is quite good. Since I would wear ear plugs anyway, it's no more bother putting in earbuds.

 

Agree with HuskerMark about equalization. I have bass set way down, treble flat, and loudness on. Play with your settings until you find what sounds good to you.

 

 

[John in VA]

One factor is the hardware version of Bluetooth that each device supports because different versions allow different transmission bandwidths.

 

BMW's bike audio spec is Bluetooth 2.0, which is fairly old and has a 3mbs max theoretical throughput. It wasn't made for quality music even with the A2DP stereo spec.

 

By comparison, the iPhone 5 and Sena 20S both support Bluetooth 4 or 4.1 which has a 24mbs max theoretical throughput.

 

I definitely hear better Bluetooth audio from my iPhone to my 20S compared to the RT audio to the 20S, possibly because they're both Bluetooth 4.

 

For example, I tested a USB drive playing MP3 music into the RT audio then via the RT's Bluetooth to the 20S. Then I compared playing similar music stored on the iPhone via Bluetooth to the 20S, bypassing the RT's Bluetooth. Big difference.

 

No wireless can be as good as a wired connection to helmet speakers so I'm planning to rig the RT's stereo speaker wires through a toggle to a 3.5mm stereo jack to plug a cable directly into the 20S so wired audio can be controlled by the RT and skip the RT's Bluetooth altogether.

 

I can't find any specs on the Bluetooth version of the Navigator V.

 

[Desert John]

A quick question: I agree on BT vs. wire quality but if I do that will I still be able to talk bike-to-bike?

 

Thanks.