I've been doing the thing where you bounce a mix, drag it into a separate player, and try to level-match by ear, and it's honestly a mess. MixCompare from Jun Murakami fixes that by sitting right in your DAW and switching between your live mix and reference audio files.
The part that sold me is the host sync. You hit play in your session and the reference follows along, so you're comparing the same bar at the same time instead of fumbling between windows. The transport has loop and in/out points too, which is handy when you're grinding on one section.
It's at v3.0.10 now, and the format coverage is broad: VST3, AU, AAX, LV2 and CLAP across macOS, Windows and Linux. There's a drag-and-drop playlist for stacking up references, meters for keeping an eye on levels, and a low pass filter if you want to check how your low end holds up next to a pro mix. No storefront or price tag on the page, the downloads come straight from the GitHub releases.
Product page: https://jun-murakami.web.app/apps/mixcompare
