Bluetooth sound improvement registry hacks
 

Thought I'd compile all the registry hacks that I've found to improve bluetooth sound quality and volume on my Mogul/WM6. Sound quality for bluetooth seems to be a major issue with the mogul - so here's everything to try all in one place.

Please note that I just found these on other forums and take no responsibility for loss of hearing related to these hacks. Remember to always back up your registry before making any changes so you can go back if things get messed up. If you don't know how to back it up you should not be messing with it...if you want to risk it I use PHM reg editor (http://www.phm.lu/Products/PocketPC/RegEdit/).

1-Change Bluetooth headphones from mono to stereo:

HKLM\SOFTWARE\Microsoft\Bluetooth\A2 DP\Settings\UseJointStereo
(DWORD:0)(Default is 1)

[joint stereo is really mono]

2-Increase the bitrate for A2DP:

HKLM\Software\Microsoft\Bluetooth\A2DP\Settings\Bi tPool (DWORD:50)(default is 30)

HKLM\Software\Microsoft\Bluetooth\A2DP\Settings\Ma xSupportedBitPool (DWORD:50)(default is 30)

[I actually set these both to 80 without issues.]

HKEY_LOCAL_MACHINE\Drivers\BuiltIn\BtA2dpSnd
Add Key 'Priority256' (DWORD:60)

[key was not on my machine by default and I'm not really sure what this does]

3-Increase Audiogateway capability:

HKLM/SOFTWARE/Microsoft/Bluetooth/AudioGateway/Capability
(Dword:69)(Default is 37)

[I'm assuming this is a bitrate setting, but not sure how this differs from those above]

4-Change the Bluetooth channel from the default:

HKLM\Softare\Microsoft\Bluetooth\Device

From there open the subfolders and find those labeled channel. The DWORD key value is the channel number. Change the number to something other than the default.

[i've only tested up to channel 7 because I'm not sure how many channels there are. This seems to have improved issues with interference and intermittent drops, but these issues seem to have more to do with where the device is in relation to the headphones than anything else. You'll have to experiment to see what works best with your gear and environment.]

5-Increase the Bluetooth microphone sensitivity:

HKLM\Software\Microsoft\Bluetooth\AudioGateway\Mic Volume
(DWORD:10)(Default:5)

6-Increase Bluetooth earpiece volume:

HKLM\Software\Microsoft\Bluetooth\AudioGateway\Spk Volume
(DWORD:10)(Default:5)

[again experiment to see what works best with your headset and environment]

I'll keep testing as long as I'm commuting. Let me know if you know what some of these do or your expereience with them and I'll update as I get more info.

From the Bluetooth Wiki: "The protocol operates in the license-free ISM band at 2.4-2.4835 GHz. To avoid interfering with other protocols that use the 2.45 GHz band, the Bluetooth protocol divides the band into 79 channels (each 1 MHz wide) and changes channels up to 1600 times per second. Implementations with versions 1.1 and 1.2 reach speeds of 723.1 kbit/s. Version 2.0 implementations feature Bluetooth Enhanced Data Rate (EDR) and reach 2.1 Mbit/s. Technically, version 2.0 devices have a higher power consumption, but the three times faster rate reduces the transmission times, effectively reducing power consumption to half that of 1.x devices (assuming equal traffic load)."

In that context, I'm not sure I understand the purpose of a parameter that sets the channel. It sounds like it wouldn't have much meaning (since the protocol would change it automatically, and rather often).

My Mogul does not contain these entries. Under AudioGateway it has only one entry: "Devices". Nothing relevant to these entries under Devices either.

I am with you...I cannot find any of the registry entries mentioned. I am using the original ROM that came on the Mogul. Have not upgraded.

I believe that these settings affect the MS voice command software.

Hmmm... I don't have MS Voice Command installed. Perhaps that explains why I don't have these registry keys?

I am in the process of exploring the registry to see if there are some "hidden" settings that will affect the general applications instead since I do not use Voice Command either.
I will post my results as soon as I find something though.

That does muddle up the issue doesn't it? I'm no expert obviously, but I have to assume these channel keys are in there for some reason and that changing them possibly effects the basis of the automatic channel switching. Since I didn't make this change in isolation, and the dropping/interference issues were and still are intermittent, I can't say how this effected my device...

These are keys in the AudioGateway folder, so at the same level as Devices (which is a folder in the AudioGateway folder). I have 9 keys here, including the capability key that is refernced in hack number 3.

I did the ROM upgrade on my mogul to 2.09, so it's possible this is why you don't see it on yours, but you might check again.

I'm confused because you didn't quote anything in your post. Which settings are you referring to specifically?