iPhone 3.0 A2DP Distortion Using Bluetooth Car Kit

I am also experiencing horrible distortion when using A2DP. I have a SCOSCHE UBRH Bluetooth receiver. I have tried streaming podcasts, mp3, apple lossless, and YouTube, using my iPhone 3GS, my old iPhone 3G, and my iPod Touch 2G, and I experience the distortion in ALL cases. I originally thought the SCOSCHE UBRH was to blame, so I tried streaming from an HTC Touch Pro, and had no issues whatsoever. I was also able to adjust the volume from the Touch Pro.

It seems the iPhone's current A2DP implementation is flawed; perhaps the output level is much too high?

I tried the network settings reset mentioned above without success. What gives?!.

Message was edited by: hunterdg

What i cal tell so far is that the 3GS is not free of this distortion!
(So hope for 3G owners)
I just also tried to reduce the music gain (only tested one example file... my music library is beeing backed up as i type this)
Result: Setting the gain to 89dB (default) significantly reduced the distortion but was not completely gone.
So i will regain my music now (with like 85 or maybe 86 dB) and see if it works then.

Since A2DP does not support MP3 transmission it sounds like a reencoding problem. Apple will hopefully adress this in the 3.1 Firmware update.

So reencoding might be a temporary solution aswell.

MacMP3Gain will also regain your (DRM free) AAC music! (at least they say so in the FAQ)

cheers!

also resetting the network settings drastically improves A2DP quality!
please fix this Apple!

Even in Germany I have this problem 😉 Paired it to my XCARLINK and when I am in Ipod-Mode, there is no volume-control, so the iPhone is playing at maximum loudness. Other Apps (like Bloom) HAVE a volume control when streaming to the bluetooth receiver and the distortion is okay (not completely gone).

So please fix this problem and give us the loudness-control in iPod mode, too!

After all it looks for me like the iPhone streams the transcoded (to SBC, which is A2DP standard) with the Mid-Quality BitPool of 35 Bits. We all know that Apple is doing anything to prevent battery drain (forbidding background applications and using this push service is just one example).
This is definately one of the restrictions they made to keep your phone alive for a certain amount of time.
I am not sure if this only applies if you dont have a power cord attached. At least Apple should increase the transcoding quality as soon as external power is available or let the user choose.
Also a volume control for Bluetooth Streaming would be a workaround.

So for now it might help to reduce the gain of your MP3 files so there are not so many dynamics in the high frequency areas.
This will reduce the sound quality of course but maybe take these clipping artifacts from the highs.

Since also the AVCRP is not fully implemented (only play/pause works here for me) i beleive apple just wanted to push A2DP onto the marked with the 3.0 release and will continue working on the usablility.

I have a Parrot MK6000 bluetooth carkit that used to work fine with my Nokia N82.

Now with My new 3GS it t=is terrible. It sounds like playing a Vinyl record in the car, jumping and skipping all over the place. Its ok for one or two tracks but once it starts to go it is totally unlistenable.

I am quite dissapointed with this as I have a 1 1/2 hour drive to work and this is when I liste to music.

Any ideas how to improve thi?

I spoke with an Apple Tech Support rep who confirmed that Apple has acknowledged the problem (at least internally) and is working on a fix to be realeased. She was not able to give me a timeframe. Thats all i needed to konw. COME ON 3.1!!

Any confirmed solutions or reasons for the distortion issues with bluetooth carkits and the iPhone stereo bluetooth feature? This is really starting to suck.

Interestingly enough, the music sounds fine through 3rd party apps like Slacker and Pandora, it's only the iPod feature on the phone that the music sounds grainy, loud and distorted.

Hi, after some testing it seems that disabling WiFi and pausing/resuming the music is enough to avoid the distortion. I also disabled the EQ.

That seems like an acceptable workaround in the waiting for 3.x where the proper fix will be implemented. It could be something like crippling the WiFi speed while being on BT as well! Or a (shudder) disclaimer from Apple that BT audio will work best with WiFi off!

All the best for finding out the workaround!

Same here only i heare from time to time a crackling noise.
the audio sounds best when i reset the network settings.

have done some testing with different headset's and all of them have the same sollution for better sound quality.

so peopel for now on turn off your WIFI 😀

Message was edited by: justin2108[NL]

3.1 hasn't fixed the problem for me.

GRRRRRRRRRRRRRRRR

Where is Apple on this? They're completely invalidating the use of Stereo Bluetooth in cars!

3.1 made no difference for me either. what's the deal? ridiculous.

interesting read that explains a lot: http://www.wirelessaudioblog.com/archives/532

Looks like apple will have to pick a different transmission scheme in order to ever get decent A2DP. unfortunate.