Brainworx created bx_solo to introduce users to the M/S technique for recording, mixing, or mastering. Key features of Brainworx´s famous M/S & Mastering products are included, like their unique Solo Buttons, which allow you to individually listen to all components of a stereo mix or stereo signal.

Comprehensive solo features include; L (Left channel), R (Right channel), M (Mono sum, mid signal) and S (Stereo-Difference, side signal). This gives users the ability to listen to each component of a stereo mix when working in M/S modes, something modern DAWs often make difficult. bx_solo is also a powerful tool for checking your tracks or mixes for errors, noises, clicks and other problems.

bx_solo contains a stepped M/S Stereo Width Control, so you can get a sense of how M/S technology can be used to expand the stereo width of tracks already recorded. Try it out on subgroups, FX returns, keyboards, or any stereo track that you’d like to spread out. A great pro trick is to use M/S processing on a rock guitar subgroup: just set the stereo width to 150% and the guitars will jump out of your speakers!

Once you become more familiar with M/S technology and techniques with the bx_solo, we invite you to check Brainworx’s more sophisticated M/S tools like bx_control V2 and bx_digital V2, which offer additional features that greatly enhance what you can do to existing stereo material. For example, expanding stereo width can lead to phase problems, particularly in the low end. Both bx_control & bx_digital include the Mono Maker Tool that allows you to convert signals below a user-defined frequency to mono, largely eliminating these low-end phase problems.


  • L (Left channel) solo
  • R (Right channel) solo
  • M (Mono sum, mid signal) solo
  • S(Stereo-Difference, side signal) solo
  • Stereo Width Control
  • Fully automatable
  • "Mouse Over" feature: adjust the parameters by holding the mouse over any knob and simply turn your mouse wheel.
  • Direct access: just type in any valid number into the text fields for direct access to the exact value

Audio Examples

Customer Reviews

  • ★★★★☆
    by Quantum-Music
    I love it to Solo the mid and the side. That way you can tell very well if there is a problem. Although, as another one said, the widening tool is so rough that it makes it completely useless. I… Read More
  • ★★★★★
    by Joe Solo
    PA has so many incredible M/S based tools to help give you a wider spectrum and wider sense of stereo panorama. And the bx_solo (not named after me) is an excellent introduction to the… Read More
  • ★★★★★
    by exertsound@gmail.com
    great plug-in!!!!! I use bx on most of my recordings and mixes..... great work.
  • ★☆☆☆☆
    Another useless one
    by Roki68
    Discrete values only, 50%,100%,150%,200%,300%,400%... It is not even toy category...
  • ★★★★★
    by chandler


Supported Plugin Formats
AAX Native, AU, AAX AudioSuite, Venue 32-bit, VST2, VST3

Supported Operating Systems
Mac OS X 10.6 through 10.11
Windows 7 through 10
Pro Tools 10.3.10 or higher or any VST/VST3/AU-compatible host running on a supported operating system

Intel CPU only (minimum 2 GHz recommended)

Intel-compatible CPU with SSE2 instruction set (Pentium 4 compatible or higher; minimum 2 GHz recommended)

System Requirements
Display resolution: 1440 × 900px or 1280 × 960px or higher
Memory: 2 GB RAM