Stem-Pack Auditor
A misaligned stem export will ruin a mixing session. Batch-analyze your audio files locally to verify identical sample counts and bit depths, then package them for delivery.
Select Multiple .WAV Stems
Or drag and drop a batch of files here.
Technical Implementation
When preparing multitracks for a mixing engineer, a common error is exporting files that do not share the exact same start and end points. Even a discrepancy of a few milliseconds can throw off phase alignment across a drum bus.
Loading thirty high-resolution .WAV files into a standard browser AudioContext would instantly trigger an out-of-memory crash. To circumvent this, the Auditor only reads the first 100 bytes of each file. It parses the binary RIFF header to extract the fmt and data chunks, mathematically deriving the exact sample count without ever decoding the actual audio payload.
Once verified, the tool utilizes the JSZip library to compile the stems into a single, uncompressed archive for client delivery.
What is a Stem Pack?
When you finish mixing a song, you usually export the entire track as one file. But if you are sending the song to a mastering engineer, a remixer, or a film composer, they need the individual parts of the song. These isolated tracks (like drums, vocals, and bass) are called stems.
A stem pack auditor helps you double check that you exported everything correctly before you send it off to a client, saving you from a very embarrassing email.
How to audit your stems
Before you zip up your files, drag all of your exported WAV stems into this tool. It will scan every single file to ensure they all have the exact same sample rate, bit depth, and duration.
If you accidentally exported the vocals at 48kHz but the drums at 44.1kHz, or if the guitar stem is cut off three seconds early, the auditor will flag it immediately in red so you can fix it before sending.
Frequently Asked Questions
Why do they all need to be exactly the same length?
If a remixer drops your stems into their software and one file is shorter than the rest, the timing will be completely out of sync. Every stem must start at the exact same zero-second mark.
What is a sample rate mismatch?
If you record your guitar at 44.1kHz but your vocal at 48kHz, the files will play back at slightly different speeds when combined. The auditor ensures every file matches perfectly.
Does it check for clipping?
Yes. The auditor analyzes the True Peak of every file. If any stem hits above 0.0dB (meaning it is distorting), it will highlight that file in red.