A2DP Headphone performance tips

[kallisti5]

On my ADP1, music playing to my bluetooth headphones drops out every 10 or so seconds for about 1 second.

When wifi is disabled, bluetooth audio is smooth and works 100%

Anyone else see this behavior on their cupcake G1 or ADP1's?

[hej]

I think this is common A2DP behavior. The bitrate for the higher quality stereo audio seems to push the limits of what BT radio's can handle. I have tried a couple of stereo BT headsets with my desktop, and there would be occasional dropout. The problem did seem correlate with wifi activity.

Look at it another way; With both full power Bluetooth and wifi going, your G1 battery will last for about two songs

[wolfmeiister]

I'm getting the same issue!!!! LOTS of dropouts on my nokia BH-604 headphones!

VERY frustrating!

I too switched off the wifi and thought it had fixed it, but it started up again.

I *SUSPECT* it may be an I/O issue - I think it happens mostly on high bitrate MP3 files (256 Kbit) so there may be an I/O bottleneck somewhere. Also seems to happen when there's high CPU / lots of apps open.

Does anyone know what codec the bluetooth headhones use (wikipedia says MPEG-1 , MPEG-2, MPEG-4, AAC, and ATRAC)? Maybe the issue is somewhere in the pipeline of: [read file off flash->decode mp3->recode into MPEG-2 or whatever->transmit to headphone via bluetooth->receive&decode&DAC] (when you think about it, it's amazing it even works! )

I'm going to do some more testing and report back on this!

Cheers,

Wolf

[wolfmeiister]

OK, an update on this - I'm now suspecting that it's a bluetooth signal issue.

I've found that sometimes if I tilt my head in a certain direction, the headphones cut out (weird I know - but reproducible) - usually when the BT signal is travelling thru my body to get to the headphones. Also I can sometimes put my hand over the base of the G1 while it's in my pocket, causing the headphones to cut out. This would indicate a weak/marginal signal being sent from the G1, or maybe a marginal antenna setup in the headphones.

However, none of these issues occur with my Nokia 6120 phone, in fact I can use the BT headphones everywhere in my apartment, whereas with the G1 they cut in and out when I move to the next room.

So maybe a bad BT signal coming from the G1??? A badly placed antenna or signal power set too low? (my headphones are nokia, so maybe incompatability?)