How to fix audio reel recorded with not constant speed?

Here is a reel to reel audio recorded with not constant speed. I captured it a 3.75ips. It sounds too fast at the beginning and gradually slows speed until it sounds correct at the end. I slowed it down to 1.875ips at the beginning but it sounds too slow. It’s not my machine because other audio reels sounds fine from beginning to end.

You can try the [u]Sliding Stretch[/u] effect. But somehow, I doubt the speed-change is linear over the whole tape.

In this situation the temp & speed should be changed by the same amount because that’s what happens when you change analog speed.

Is there a Windows and Mac music player that has speed control which will also change the pitch? I tried VLC and others, they maintain the same pitch, so a chipmunk still sounds like a chipmunk at a slower speed. Preferably with keyboard shortcuts that can adjust speed+pitch at 5% increments.

A “regular” speed change effect (like Audacity’s Speed Change effect) will change speed & pitch together just like changing the speed of a record or vinyl tape.

There is a speed correction application called [u]Capstan[/u] that can probably fix it but a 5-day rental costs $200 USD.

Eventually, somebody will probably reverse-engineer it (if that can be done without patent violations) and it should become more affordable.

Recorded into Audacity R2R not constant speed.wav from GoogleDrive link at the playback speed.

Used the speed change (see Jpeg)

Done a few nips and tucks
R2R not constant speed.wav.jpg

Thanks for the effort but I assume it won’t be effective on long duration like 30 mins of audio.

Try it and see.