The free demo
It is the complete application, not a cut-down version. Load your own multitrack, let it mix and master, read every decision it made, and A/B it against your original — all of it, on your machine, before you decide anything.
About 280 MB installed · we ask for an email so we can send you the link and a short guide to reading the Engine Notes. The application itself needs no account, and the null-test pack below needs nothing at all.
The files are StemMasterDemoSetup.exe and StemMasterDemo.dmg, published by NOMZ Studios and served from our own downloads.nomzstudios.com. The Mac disk image is signed and notarized by Apple, so it opens with a double-click.
The software it installs has been reviewed and covered independently — an 80% review at Noizefield, news at KVR Audio and rekkerd — more on the press page.
I love your reverb. The space it creates is fresh and spacious which I feel inspired by.
Windows will almost certainly stop you the first time, and it looks like nothing happened. You get “Windows protected your PC”, and the only button on it is Don’t run — click More info first, then Run anyway. That notice is about the installer being new and not yet signed by a certificate authority, not about anything found in it. If you would rather look before running anything, the coverage above and the null-test pack below need nothing installed.
What the demo will not do
Two limits, and they are the only ones:
- Exports are disabled. You can hear the finished master in the app, but you cannot get the file out of it.
- A short tag plays periodically over mastered playback, so the demo cannot quietly become the product.
Everything else is the paid application. Same engines, same console, same Engine Notes, no time limit and no watermark on the interface.
What you can actually try
- Drag in your own stems — WAV, AIFF, FLAC or MP3, at any common sample rate. Four of them or forty; mixed rates are resampled for you.
- Let it mix before it masters: levels, pans, per-track automation, vocal riding through busy sections, bass ducking under the kick.
- Read the Engine Notes — every decision written out in plain language, which track, how much, and why.
- Flip the A/B against your original. It is loudness-matched, so nothing wins by being louder.
- Move any fader or pan knob afterwards. The master re-renders around your change in seconds, holding the loudness target.
Where your audio goes
Nowhere. Your stems and masters are processed entirely on your own machine — there is no upload, no queue and no account.
StemMaster ships with two engines. The built-in analysis engine needs no key and no internet at all, and it is what the demo runs on out of the box. The optional AI engine takes a plain-English direction and decides the whole treatment around it; it needs your own API key, and it receives compact measurement summaries only — never your audio.
No sign-in, no usage tracking, no analytics in the installer. Full detail on the privacy page.
If you want to check our claims first
Fair. There is a free pack — a mix, its exported stems and the master, 24-bit FLAC, straight out of the app with a README. Import the stems, set every fader to unity, invert the mix, and the residual drops to −142 dB. It takes about thirty seconds and needs nothing from us.
Download the null-test pack · 21 MB, no sign-up
When you have tried it
One purchase, yours forever — no subscription, and free updates across the 1.x series. The licence activates on up to three of your own machines, and you can deactivate and move it yourself at any time. Refunds run fourteen days, no questions asked.
One-time purchase, free 1.x updates.
If you are on neither
There is no Linux version and none is announced. The Mac build needs Apple Silicon (M1 or later) on macOS 15 or newer; Intel Macs are not supported, and neither is an older macOS, so if that is your machine this will not run on it. On a phone or a tablet, or on hardware we do not cover, a browser-based service will serve you better — we say which ones and why on the comparison page.