M4 Multiband Compressor is designed to be the ultimate mixing and mastering tool. This compressor has 3 user-controlled crossovers resulting in 4 bands that can be as wide or as narrow as you desire. The unique display for M4 shows all of 4 bands together, each with a specialty meter to show threshold, peak level, and gain reduction for the respective band in realtime. All 4 bands are completely in your control by allowing attack time, release time, threshold, ratio, and makeup gain to be set. M4 also has optional auto-makeup gain as well as internal bypass. M4 can handle anything from subtle peak control to bus compression, and even mastering. This powerful multiband compressor should feel at home in any producer's arsenal. If you don't believe us, check out the sound examples. Or better yet, download the demo and give it a try!


  • 3 user controlled cross-overs
  • Unique meters that combine peak level, gain reduction, and threshold into one.
  • Threshold, Attack, Release, Ratio, and Gain controls
  • Ability to solo each frequency band to hone in the perfect amount of compression
  • Automatic gain correction
  • Low CPU usage

Supported Formats

Windows (32bit) Windows (64bit) MacOS (32bit) MacOS (64bit) Linux (64bit)

*LV2 for MacOS and Windows is planned to be supported by late 2020.


M4 Multiband Compressor contains 4 meters. One for each band with a range of -36dB to 0dB. Each meter is comprised of 4 main parts: A threshold indicator, a peak meter, a reduction meter, and a text overlay.

Threshold Indicator

The threshold indicator is represented by a horizontal cyan colored line. It will change in real-time based on the corresponding threshold slider for that band.

Peak Meter

The peak meters represent

Gain Reduction Meter

The grain redection meters are represented by the dark section on the meters. It is shown as a difference between input and output.

Text Overlay

The text overlay is the slightly darker section at the bottom of the meter. Unlike the other parts of the meter, it does not stretch as the crossover frequencies are changed. This overlay shows input level and output level in dB in real-time.


There are 3 cross-over frequencies that can be controlled via the UI. These 3 cross-overs determine the range of the 4 bands.

The Frequency Handles

The display for M4 is interactive. There are no knobs for controlling the frequency cross-overs. To adjust one of the cross-overs you must left-click on the handle. While holding down left-click drag the mouse from left to right. You will see a text box appear by the handle to show what frequency the crossover is set to.


While it is possible to automate the frequency cross-overs through a DAW, it is not recommended. If you chose to use automation be careful that the cross-overs never overlap. The parameters for the cross-overs are labeled as F1, F2, and F3. Make sure that F1 is never a higher value or equal to F2 and that F2 is never higher than or equal to F3


In this section we will go over all of the controls for M4.

Frequency Cross-overs

M4 has 3 Frequency Cross-over controls labeled as F1, F2, and F3 respectively. The cross-overs all share the same range, but they may not overlap. This means that F1 can never have a larger value than F2, and F2 can never have a higher value than F3. It is possible to pass this restriction through automation but it is not advised.

Range: 40.0Hz - 20,000Hz
Default Value: 190Hz

Range: 40.0Hz - 20,000Hz
Default Value: 901Hz

Range: 40.0Hz - 20,000Hz
Default Value: 4260Hz


M4 has 4 compressors hence the name M4. All of the compressors behave identically and have the same controls. The bands controlled by the compressors are from left to right "Low", "Low-Mid", "High-Mid", and "High". The controls for the compressors are as follows.

Range: -36dB - 0dB
Default Value: -3dB

Range: 1.0ms - 2000ms
Default Value: 20ms

Range: 1.0ms - 2000ms
Default Value: 40ms

Range: 1 - 100
Default Value: 4

Range: 0dB - 12dB
Default Value: 0dB

Auto Gain

M4 features automatic gain correction which keeps track of gain changes over relatively long periods of time, and applies gain to the output signal based on these changes.