Download of bx_solo 1.2.1 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The software is included in Audio & Video Tools. The most popular version among the program users is 1.0. Downloadrequest?file=bx_so.dmg is the most common filename for this program's installer. The actual developer of this free software for Mac is Brainworx Music and Media GmbH.
From the developer:
bx_solo is a nice little tool that we have designed to get you started with and used to the way we approach the M/S technique
You may want to check out more Mac applications, such as M-Audio Key Rig, which might be related to bx_solo.