The Harshness Control allows you to eliminate unpleasant high frequencies from complex signals and mixes. bx_refinement’s intuitive controls let you adjust various aspects of the sound with ease. Based on M/S (Mid/Side) processing, it imparts a tube-like analog smoothness and is a boon for mix engineers looking to tame unpleasant digital harshness on individual tracks.

Add Tube-like Tone
bx_refinement is not an emulation of a certain tube sound. Instead, it combines several characteristics found in ultra-musical tube-based equipment to give you an effective tool that is easy to operate. As you tweak the bx_refinement controls, the tube graphic gives you precise visual feedback showing you how intensely the process is being applied. Simply look at the tube’s glow and you’ll see how much, how fast, and how dynamic the plugin is affecting the signal.

Easily Target Problem Areas
With powerful, simple controls, bx_refinement allows you to quickly identify and discard offending frequencies. The core of bx_refinement is its Damping Control, which features a dynamic peak band EQ to reduce harsh frequencies. The Solo Filter button lets you listen to only the frequencies you’re removing, while the Soft/Hard function sets the character of the processing.

Dynamic Flexibility
Implement the oscillation option to create nice warming effects. You can adjust the speed of the oscillator with the duration knob, and even sync it to your DAW’s tempo to emphasize rhythmic aspects of your mix or master. The bx_refinement is a processor that will truly stand alone in your sonic toolkit.


  • Reduces harshness and breathes life into recordings
  • Dynamic or modulation-based damping of unwanted frequencies
  • Soft & hard damping provide second order filtering and higher order filtering respectively
  • Solo filter allows you to hear just what you’re removing from the recording
  • Subtle saturation and presence controls enhance the material without changing its character
  • Independent processing of Mid and Side channels in M/S recordings

Audio Examples

Industry Reviews

  • Joe LaPorta
    Joe LaPorta

    Since a majority of my chain consists of analog gear, I'm very selective when it comes to which plugins I use.  bx_refinement has definitely been a great addition to my arsenal.

  • Siegfried Meier
    Siegfried Meier

    This plugin is the coolest and strangest tool we've come across. It works wonders on harsh overhead and guitar tracks that we've had come in for mixing. In a mastering setting, it really helps… Read More

  • Glenn Schick
    Glenn Schick

    I've been an analog based mastering engineer for the past 20 years. When people used to ask what plugins I used, I would always respond with "Plugins? I don't use no stinking plugins." And then… Read More

Customer Reviews

  • ★★★★★
    by Ivochkin
    This plugin is amazing! Really! That was a love from the first try. It saves me so much time EQing harsh frequencies. I can't live without it now.
  • ★★★★★
    by microlin
    One of the best Plug In´s I ever heard.A game changer in your mix Bus and also in Mastering. Absolut hand´s on and in seconds all will sound better for min. 50%.Warm and punchy and also cut´s… Read More
  • ★★★★★
    by Alex Hepting
    If you once get it you won't miss it. Glues perfectly like honey, deals with frequencies about 5k and has creative pumping effect for something like pads.
  • ★★★★★
    Great analog sound in no-time!
    by Mikael Lind
    The bx_refinement can do wonders for you if you know how to use it. It's not something that you will be able to hear instantly on all instruments, especially if you have no access to a good listening… Read More
  • ★★★★★
    by 4th Disciple
    This plugin is a big time saver in helping to remove problematic frequencies. The bx_refinement plugin and the bx_digital v3 are my secret weapons.


Supported Plugin Formats
AAX DSP, AAX Native, AU, AAX AudioSuite, Venue AAX, VST2, VST3

Supported Operating Systems
Mac OS X 10.8 through 10.12
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


With the Installation Manager, you can select, download and install just the Plugin Alliance products and formats you need for your system. During this initial release, we at Plugin Alliance look forward to hearing the feedback of our valued customers, as your input will help shape future versions of this utility.