Bluetooth audio stutters on every device

About a month ago I started noticing that the audio through Bluetooth would stutter and/or fast forward randomly while connected with my phone (oneplus one) to one of my cars (vw tiguan 2012), then it started happening with my citroen c3 as well. a couple of weeks ago I bought a Philips soundbar with Bluetooth and the same thing happened. same with a pair of Bluetooth earbuds that I have. I thought it was my phone, but I tried with my mom's phone (asus zenfone 2), my sister's (galaxy s3) and my laptop (asus rog) and pretty much the same thing happened. I noticed that it would stutter less when wifi was off on the devices and it would improve for a little bit, only to then get as bad as it was before. this however wouldn't explain why it was happening in my cars as well (although the problem while away from home isn't as bad as with the soundbar). why is this happening?
(note: my soundbar is in front of my tv, the router is in between the two. my previous soundbar which broke some months ago didn't have any problems, nor did anything Bluetooth until about a month ago. I never changed the wifi or Bluetooth settings on any of the devices. I also tried disconnecting my smartwatch but nothing changed)
 
My guess is that the new soundbar is picking up interference from a nearby source - magnet, EMF, etc. Alternative --a driver change that is not quite right. No easy answer. Best approach, map out the 10-12 things you can test. Identify a reliable 'error condition' - and test each item on your list until the error disappears. Keep careful notes.

No easy answer.

http://www.tomsguide.com/faq/id-2313252/minimizing-bluetooth-speaker-interference-sound.html
 
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