Restoring Old Cassette Tapes and Archival Recordings
Updated: Aug 13
I recently took on a request to restore a cassette tape recording — something we do a few times a year, much less often than when this service started.
Note upfront: for cassette tapes, VHS, DAT, and other physical media, we can only work from an already-digitized file. We don't accept physical tapes by mail, especially from clients outside Japan — so if you have a box of old cassettes, the first step is digitizing them locally, and from there we can take over.
The source: a singer's only surviving recording of her own voice
The client was a woman who'd spent her twenties singing at small live venues around Roppongi and Shinjuku. She has a completely different career now, and the only proof that period ever happened is a cassette recording from about 30–35 years ago — a mix of cover songs recorded live. She wanted it cleaned up enough to put on a CD.
Hiss noise, solved by decoding Dolby B correctly
The tape itself was an ordinary cassette, and it had the hiss noise that's familiar to anyone who grew up with cassette decks. Most consumer decks of that era supported Dolby B noise reduction, which cuts hiss when engaged during recording — the trick is that you need to decode it the same way on playback.
There was no label confirming Dolby had been used, so I tried a few settings on a deck with switchable Dolby B/C/S. Dolby B turned out to be the right call — the hiss cleaned up dramatically once decoded correctly, and from there the audio was captured digitally through an audio interface.
The bigger problem: instrument balance, not noise
Once the tape hiss was under control, the real issue was how the original recording had been mixed. It sounded like vocals, backing track, and a drum machine had all been summed together at the venue's PA mixer, and the line-out from that mixer was what ended up on tape — vocals and drum machine loud, piano barely audible (there was no mic on the piano itself, just some bleed picked up off-mic from the room), and light but noticeable audience noise underneath.
This kind of recording — a raw PA line-out with no real mix — was extremely common for live-venue tapes from the 80s and 90s, and a lot of those recordings are effectively unlistenable as a result. With modern AI-assisted source separation, it's possible to rebalance the individual elements after the fact, even from a rough two-track recording like this. Since the budget allowed for more detailed work, we also cleaned up crowd noise and a few stray comments from the audience.
After the detailed noise and balance work, the final step was mastering to bring the sound up closer to a modern release — delivered back to the client as a CD.
Beyond music: archival audio for documentary and family history projects
This kind of work isn't limited to musicians. Old interview tapes, oral history recordings, and archival footage audio all run into the same problems — tape hiss, uneven levels, and decades-old recording gear. If you're restoring archival audio for a documentary or a personal project, we can help once the source is digitized.
Comments