Midside Matrix

Name: Midside Matrix
Author: Goodhertz

by Goodhertz · Imaging · Mid/side encoder and decoder

Not rated yet

Midside Matrix is a free mid/side utility for converting between L/R and M/S and adjusting stereo width.

It has M/S gain faders, mute, flip and a large goniometer, and it is free.

Best for: Mix Bus, Mastering, Acoustic Instruments. Genres: all genres.

Keywords: mid/side, wide, free, metering, simple, full mix, bus processing, mastering, minimal controls, mix bus, mixing, utility.

What it does

Midside Matrix provides "easy Mid/Side conversion." It is the free, stripped-down sibling of Goodhertz's Midside: M/S encoding and decoding and simple width changes, without extra buses or gain staging.

Encode and decode: input and output each switch between L/R and M/S, so it can decode M/S mic recordings or wrap other plugins in an M/S chain.
Mid and side faders: high-resolution gain faders, each with an on/off switch.
Width: raise the side level to widen a stereo source, lower it to narrow, or switch it off to fold to mono.
Metering: pre- and post-fader peak meters with clip indicators, and a large goniometer.
Flip L/R: swap the left and right channels.
Automation: every control, including the bypass, is click-free and automatable.

Goodhertz's downloads page lists version 3.14.1 (June 2026) for its plugin line (the online manual covers 3.13). It is stereo in and stereo out. It is free and part of the Goodhertz Free Series.

Source: Goodhertz product page

When to use it

Midside Matrix is the pick when you only need the M/S conversion itself. Compared with Ozone Imager, it has no multiband width, and compared with S1 Stereo Imager it offers no rotation or asymmetry, just a clean mid and side level with metering. Its strength is routing: two instances let any stereo plugin, or analog hardware, work on mid and side separately. Goodhertz's paid Midside adds tilt EQs, width modes and bass mono on top of the same basics.

Best for: decoding M/S mic recordings, building M/S processing chains, and quick width or mono checks.
Genres: any.
Look elsewhere if: you want width tools with more shape, such as multiband width or bass mono; Ozone Imager or Goodhertz's Midside go further.
Tip: put one instance before a stereo processor set to output M/S and a second after it set to input M/S, so the processor works on mid and side.

What producers say

The few write-ups praise it as a simple, reliable free tool; none list real faults.

Production Expert (2021) recommended it for M/S recording and processing, noting that M/S mic setups are "often incorrectly setup or avoided altogether"; it suggested a +6 dB side boost to widen and muting the side to go mono.
KVR users rate it 5 out of 5 from 1 review, calling it "simple and user friendly" with clear metering.

Where to buy

Goodhertz: Free

Tutorials and reviews

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