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Whenever I turn on my Nokia bluetooth headphones they automatically connect to my Macbook. The problem is they always connect to the Mono (and not the Stereo) profile. So I have to disconnect and reconnect with the stereo profile. Is there anyway to either delete the mono profile or set the stereo profile as the default?

Mac OS X 10.6 Nokia BH-905

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Are there (before reconnecting) mono and stereo options available under the BH-905 item in the MacBook's Bluetooth menulet? Or does it show only mono? –  koiyu Apr 8 '11 at 15:12
    
The menulet always includes both options. It's just that if I accidentally choose "mono" just once this becomes the default option the OS automatically chooses when it auto-associates. However, I've repaved my machine since I first asked this question. I've been extremely careful not to choose mono and have been fine since. As long as I never get my mouse clicks wrong it'll continue to work OK ... –  xanadont Apr 8 '11 at 15:19
    
So the selection sets it as default — that's 50% of your question covered :-) Deleting the mono profile altogether, though, seems to be a harder thing to work around. –  koiyu Apr 8 '11 at 15:35
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No, it doesn't answer half of the question. Sometimes the headphones don't automatically associate; I'd say about 25% of the time I have to manually tell OS X to connect to the headphones. At this point I mouse to the menulet, hover "Nokia BH-905 >", and two menu choices appear "Use As Audio Device (Mono)" and "Use as Audio Device (Stereo)". If I ever accidentally choose mono then I'm screwed forever - next time it autoconnects I get the problem as described above. And at which point I can never put it back to defaulting to stereo ... and I don't consider repaving a solution. :P –  xanadont Apr 8 '11 at 15:46
    
I see. What does the BH-905 show after you've chosen mono/stereo? (I have a pair of BH-501's which show "Don't use as Audio Device" If I select it, the menu reverts back the "Use as Audio Device (Mono)" and "Use as Audio Device (Stereo)" options, without losing the bluetooth connection.) –  koiyu Apr 8 '11 at 16:01
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1 Answer

Since no-one has stepped up with an answer, I'm going to add a few things that may help get you (or someone else) closer to an answer.

In a nutshell, your question is about HSP - the mono headset profile and A2DP - the stereo profile.

HSP was designed for two way, low latency (delay) audio - designed for the limited spectrum telephone lines send for human voice frequencies. It sacrifices sound quality needed to make stereo music sound good.

A2DP is all about better quality and allowing different encoding schemes to get the best music over a bluetooth link (with potential interference) and sacrifices two way audio, microphone, and adds delay to queue up enough music to allow playing over momentary interference or pauses in bluetooth.

Your headset speaks both - so if you could get your headset to only advertise A2DP, the mac would be forced into stereo. I don't think it's possible, but you might see if Nokia allows you to control this.

Even if you were willing to give up HSP completely on the mac, I don't know if you can delete the driver files and re-program the bluetooth board to not negotiate HSP with your headset.

I do know you can use the Bluetooth Explorer (part of Xcode 3) to systematically clear the preferences and play around with things to see if you can really remove all records of the mono pairing. Whether you could edit the profile to delete HSP from the pairing record is hard to know unless you wanted to experiment and learn in depth how this was engineered.

Bluetooth Explorer - Modify Software Configuration

Some things that will help you track the settings are in /Library/Preferences/com.apple.Bluetooth.plist and /Library/Preferences/Audio as well as using the option key while pressing the mouse on the bluetooth menu to expose the bluetooth link address of each device so you can match the plist files to actual devices. (Or get the developer tools and use Bluetooth Explorer)

Lastly, you might run the Bluetooth diagnostic utility to see if interference with other devices might be causing your mac to systematically choose HSP which is more nimble than A2DP.

Good luck - I don't have a device with both A2DP and HSP to test, but I can tell you that my A2DP device is by far the worst when it comes to the % of time it fails to connect. (Which is the point where you choose whether to connect as mono or stereo) I usually need three connect attempts to get it working and I'm in a very low noise environment. It works really well once paired - just hard to connect.

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This is a really excellent explanation. (I don't know how) but I think this should be part of the wiki). –  Global nomad Nov 27 '11 at 10:52
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