Odd Intermittent Bluetooth Issue - Audio Stream Falls Apart

[Aaron407]

I'm using a stock, unrooted Galaxy S5 running 5.1.1, and I'm fighting with significant intermittent bluetooth streaming issues. I used to be able to stream without any issues to my two Sony BM10 receivers, but, over a winter of having a software update or two, installing various apps, etc., it's no longer working consistently. Everything will play fine for awhile over bluetooth, but intermittently the sound will fall apart heavily for a minute or two straight as if the signal is dropping out. During the dropouts, which happen two or three times per second for the minute or two, there doesn't seem to be pausing of playback, and the elapsed time on the display continues as if nothing's happening. After awhile, the playback goes back to normal.

Other traits of the behavior:

• It happens seemingly randomly;
• It isn't related to distance between the phone and receiver (happens whether it's 10' or 1' away);
• It happens with both of my Sony BM10 receivers, which use Apt-x and (I believe) are operating on class 1 bluetooth for increased range;
• Happens on wifi and 3G/4G, regardless of the media player app, and independent of the screen being on or off;
• Cleared the cache partition, but it didn't help; cleared data and cache for both Bluetooth and Bluetooth Test apps;
• Phone seems to occasionally bog while the audio problem is occurring, but it doesn't seem to happen every time;
• I watched the processes with "CPU Monitor" before, during, and after the audio was falling apart, and there weren't any displayed apps with major memory or CPU fluctuations;
• The bluetooth connection never disconnects;
• There doesn't seem to be issues when streaming to a Bose Soundlink Mini nor a Kicker Amphitheater stereo with the S5, which I believe operate on class 2;
• The only 2.4 GHz wifi in the area was set to channel 11; in case there was interference, I changed it to channel 1, but it made no difference;
• I downloaded and installed Poweramp, set the bluetooth buffering to 750 ms, and changed the audio priority to its highest; the playback problem still happened.

I'm at a loss for where to look next. I will be testing with another S5 and a Galaxy Tab S with the BM10s to see if they have any issues, but it definitely feels like an issue with my S5 specifically as I didn't have issues with the S5/BM10 combinations last summer, and nothing with the BM10s has changed. Any suggestions of what to look into next, other than rooting and running a custom ROM/kernel? Any help would be greatly appreciated.

 

[Aaron407]

Thought I'd follow up on this. The issued turned out to be a Kicker Amphitheater bluetooth speaker system that was causing interference, even when not paired. Flipping the power switch to off on the Kicker unit fixes the issue.