How to Check Stems Before Sending Them

Why a pre-delivery check matters

A stem package can look complete in Finder and still contain a serious problem. One file may begin late, another may stop before the reverb tail, a vocal stem may be silent, or two differently named files may contain the same audio. These mistakes are rarely obvious until someone has already created a session and started working.

For a mixing engineer, the best stem delivery is not simply a folder of audio files. It is a verified package: clearly named, technically consistent, aligned from the same start point, and accompanied by enough context to rebuild the intended balance.

The 10-minute checking workflow

1. 1
   Confirm the delivery specification. Before exporting, check the requested file type, sample rate, bit depth, start time, naming convention, and whether processed or dry stems are required.
2. 2
   Create a clean export folder. Don’t mix old bounces, rough versions, and final deliverables in one place. Export into a new folder with a version or date.
3. 3
   Check file count and names. Compare the folder against the expected stem list. Look for missing groups, vague names, and accidental copy suffixes like “(1)” or “copy”.
4. 4
   Verify technical consistency. Check sample rate, bit depth, channel count, and file format. A single outlier should be explained before delivery.
5. 5
   Load every stem together. Use a blank DAW session or a dedicated checker. Place every file at the same timeline origin without moving it by eye.
6. 6
   Press play from the beginning. Confirm the song starts correctly, count-ins are intentional, and no stem enters a few samples, frames, or bars late.
7. 7
   Scan the full timeline. Look for shorter waveforms, unexpected gaps, truncated tails, and files that continue long after the rest.
8. 8
   Solo every stem briefly. Confirm the name matches the content, the file isn’t empty, and no unintended source has been printed.
9. 9
   Listen to the full sum. Compare the combined stems with the approved reference. The balance may differ if master-bus processing is excluded, but the arrangement and core content should agree.
10. 10
    Package only the verified files. Include the reference mix, tempo and key when relevant, notes about processing, and a short readme if anything needs explanation.

What to listen for

Don’t rely on visual checks alone

Waveforms are excellent for spotting length differences, silence, and obvious duplicates, but they don’t prove that the content is correct. A stem can have a healthy-looking waveform while containing the wrong guitar take, an outdated vocal comp, or a processed version that wasn’t requested. Visual review should always be combined with short solo checks and a summed playback.

When the stems won’t recreate the reference exactly

A perfect match is only expected when the stems were created from the same routing, pan positions, automation, and gain structure as the reference, and when no additional master-bus processing was applied afterward. Limiters, bus compression, clipping, dither, analogue summing, and effects fed from multiple sources can all prevent an exact null.

The goal of the preflight is therefore to distinguish expected mix differences from genuine delivery errors:

• Expected: small tonal or level differences from excluded master processing.
• Errors: missing parts, wrong sources, misalignment, truncation or format faults.

Engineer checklist