By setting up as shown below, you connect the bluetooth speaker to Mac via bluetooth, then the sound becomes very noisy and bad. But if you connect the speaker and mac via audio-wire, everything is all right, and the sound quality shows what it should sound like.
Device: 2014 RMBP 13" OS: 10.11.1 Boom2 Setup: Fidelity + Advanced equalizer mode on "My Macbook Pro"
I can see that this problem does not annoying me only, some of the bluetooth speaker users are already notice and report this problem to you.
Hope you can find the solution and fix it ASAP.
Thanks for your great work in helping to advance their poor audio-output performance.