Hear how your mix translates. Without exporting nine times.

The installer is not code-signed yet, so Windows asks before it runs. Which message you get depends on the PC:

1. Your browser says the file is not commonly downloaded. Choose Keep (in Edge: the three dots next to the download, then Keep, then Keep anyway).
2. A blue box says “Windows protected your PC”. Click More info, then Run anyway. The button only appears after you click More info.
3. A box says Smart App Control blocked it, with no Run anyway button. That PC has Smart App Control switched on, which refuses every unsigned program. This version cannot be installed there. Windows lets you switch Smart App Control off in Windows Security, but it cannot be switched back on without reinstalling Windows, so we do not suggest doing that for us. Write to support@quantumaccordbg.com and we will tell you when the signed version is out.

Where it installs. The plugin goes to C:\Program Files\Common Files\VST3\CheckMyMix.vst3, the folder FL Studio, Ableton Live, Cubase, Reaper and Studio One all scan. The app goes to the Start menu as CheckMyMix.

In FL Studio. Open Options → Manage plugins and click Find installed plugins. Then open the Mixer, select the Master, click an empty slot — use the last one — and choose CheckMyMix (search for it, or look under Installed → Effects → VST3).

Only want the plugin? Download the VST3 1.0.1 as a zip (3 MB). Unzip it and copy the whole CheckMyMix.vst3 folder into C:\Program Files\Common Files\VST3. It is the same unsigned plugin, so a PC with Smart App Control on will still refuse to load it.

CheckMyMix is also a plugin, so you can check the mix without leaving the project. Put it in the last slot of the master, pick a listening profile and press play; the same nine profiles, Match loudness, Bypass, mono check and spectrum as the app. Bypass it or take it off before you export — it is for checking a mix, not part of the final sound.

Windows: the Windows installer above includes the VST3 plugin and puts it where FL Studio, Ableton Live, Cubase, Reaper and Studio One look for plugins. In FL Studio, run Options → Manage plugins → Find installed plugins once.

macOS: an Audio Unit for Logic Pro and GarageBand and a VST3 for FL Studio and other hosts, in one installer, signed and notarised by Apple. Download the CheckMyMix plugin 1.0.1 for macOS (12 MB, Apple silicon and Intel, macOS 11 or later).

The plugin is a port, not the same code: the Mac app is built from Apple's own audio units, which do not exist on Windows or inside a plugin. The port is held to the app by measurement — frequency response, compression and distortion are compared tone by tone in automated tests — and agrees with it to within about a third of a decibel on pink noise. It adds 256 samples of delay, which it reports to the DAW. The Windows build is new, and has been tested by automated runs rather than on many PCs: if something misbehaves, tell us at support@quantumaccordbg.com.

Does: every profile now changes the sound. Picking one sets a bass high-pass, a low-shelf, four bands of EQ, compression, a touch of distortion on cheap hardware, and a blend toward mono — live, mid-playback, with no gap in the audio. Bypass takes all of it out in one click so you can A/B against your monitors. Match loudness (on by default) plays every profile at the same overall loudness as your mix, so you judge the tone and not the volume — a budget phone is otherwise about 4.5 dB quieter, and quieter always sounds worse. Turn it off to hear the real drop. The spectrum shows what is actually coming out after the profile, not a drawing.

Loop a section: press A and B (or [ and ]) to repeat the chorus or the drop while you flip between profiles — gapless, and shaded on the seek bar. Open a mix any way you like: the Open Mix button, drag a WAV or MP3 onto the window, drop it on the CheckMyMix icon in the Dock, or use Open With in Finder. Space plays and pauses.

Mono check: a phone speaker folds your mix to mono, and anything out of phase between left and right cancels there — a widened lead or a stereo synth can simply vanish. CheckMyMix reads your mix as it plays and warns you, in plain words, when folding to mono would cancel part of it. Wide or hard-panned parts are fine in mono and do not trigger it.

Each profile is checked by rendering test tones through the same audio engine the app plays through: a 60 Hz tone must lose at least 15 dB on Budget Phone and gain on Car + Subwoofer, a one-sided signal must fold into both ears on the mono profiles, and Bypass must land within half a decibel of untouched.

Does not: reproduce any particular phone or car. The profiles are modelled from how each class of device behaves — small drivers lose bass, closely spaced speakers lose stereo, cheap amplifiers limit — not measured from specific hardware, and they have not yet been tuned by ear against real systems. Treat them as a fast first check, then confirm on the real thing before release.

Not a mastering plugin. Not another EQ. It is a mix-translation tool for producers, mixing engineers and independent artists — the goal is confidence before release, not a louder master.