Mainstage 3 crackling sound while use Beats headphones

I'm getting a crackling sound on Mainstage 3.2.4 while using my Beats solo2 wireless headphones.

When I turn off the headphones and use the built-in audio output then the crackling sound goes away. I bought Mainstage a couple of days ago and don't recall hearing this sound when I used it on the first day. I noticed it while I was using the software yesterday. So possibly I accidentally changed a setting?

I've tried changing the buffer size and it doesn't change the crackling sound at all.

I'm using a MacBook Pro running El Capitan 10.11.5

2.7 GHz intel core i5 processor

16 gigs of ram