Stem Checker

Stem Checker takes the leg work out of checking stems.

Stems, by which we mean multitrack elements that can be reconstructed to recreate the master recording, frequently have issues which mean that they don’t fulfil this basic purpose. And all too often, these issues are only discovered once they’re in a DAW session and being worked on. Of course, it would be better to discover these things before they hit your DAW, and that’s exactly what Stem Checker is for.

Stem Checker is a lightweight standalone utility for macOS that is designed for music producers and engineers to verify stems without opening a DAW. It functions as a pre‑session QC stage, and the promising thing about Stem Checker is precisely this focus. It’s there to solve one problem, and tools that do that are often the most useful.

Toolkit

With stems dragged and dropped into the DAW‑style timeline layout, which will be immediately familiar to users, navigation is nice and intuitive. Playback is ‘tape style’ and starts from where it was last stopped, but if you enable Anchor mode, you can start playback from the same point every time. You can use Option‑drag to create looped sections. You can pin tracks to the top of the page and zoom horizontally and vertically using Command‑Plus. So far, so good.

Stem Checker can automatically identify if there is a print of the whole mix included in the stems, and will make it available in compare mode so you can A/B between the combined output of the stems versus the master. This will also be automatically level‑matched; a very efficient auditory check that all is well.

A variety of common technical issues, if present, will already have been identified: length mismatches, sample rate and bit depth mismatches, missing audio and level clipping are all flagged by the display of icons in the track headers. Content‑based issues, such as duplicate stems and dual mono files, will also be detected. Dual mono is particularly useful as it’s so common for DAWs to output mono tracks as stereo prints. And from a housekeeping point of view, keeping mono content on mono tracks is, in my opinion, the way to go. The colour‑coded icons in the track headers aren’t self‑explanatory, but explanation is provided in the Issues panel on the right of the track timeline, and if you hit the info button at the top of the UI a key is provided for all detectable issues.

Batch Rename was an unexpected bonus: a useful, simple tool for removing prefixes and suffixes, with a find and replace function and the option to add a prefix. This makes for speedy renaming of files to your own preferred convention. In this top row of buttons, you’ll also find a dedicated export window and built‑in cloud support. So, for example, you can upload to Dropbox directly from within the application.

It’s fast, it’s efficient and it does what it sets out to do efficiently and rather elegantly.

In Use

So how is it in use? I found it very intuitive. If you’re not sure about anything, just click the info button and you’ll probably find the answer. This isn’t the deepest of applications. It’s fast, it’s efficient and it does what it sets out to do efficiently and rather elegantly. I like it.

So, should you spend money on a separate application to do something you can do within your DAW? I’d argue that if you use stems a lot, then yes. Checking the assets you’re using before importing to your DAW, so that you discover the issues before you start rather than while you’re building your session, or even while you’re mixing, is the correct point in the process to do these QC checks, and it avoids potential session clutter, fixing issues as you discover them.

This is just as useful when you’re creating stems to send to somewhere else. If you’re sharing stems with other people it can save you from looking like you lack attention to detail. It seems to cover the important stuff and achieves exactly what it sets out to do. Considering I used to use a separate piece of software just to detect dual‑mono files on import, I’d say having an application that covers all bases so efficiently is very worthwhile.