cassette tapes sound warped and distorted

[safetytube]

Many of my most cherished cassette tapes have a warped and distorted sound due to damaged tape.
They sound like the tape isn't moving fast enough. Can this be fixed with Audacity?

[Locopomo]

If it's simply a case of the tapes not moving fast enough, at the risk of stating the obvious that points at the cassette deck rather than the tapes themselves. Audacity can in fact correct speed (tempo) errors if it's a constant rate, but you talk about "warped and distorted" which sounds more complicated than that. If it's a case of noticeable fluctuations in speed due to tape stretching, accompanied by a loss of signal quality due to degradation of the magnetic coating on the tape, then I doubt that there's much Audacity can do about it I'm afraid. However, if you could post a short example online somewhere, it'll be easier to say for certain.

[waxcylinder]

I would try cleaning the tapedecks transport - paricularly the capstan and the pinch-roller that propel the tape - I'd also give the heads a gentle clean while you're at it.

WC

[steve]

After making sure that your tape recorder is clean and in good condition, it can sometimes help to fast forward through the tape once in each direction - old tapes can sometimes be wound too tight, or unevenly, causing this kind of problem.

Disclaimer: Old tapes can become quite fragile and the stress of fast winding can sometime be just enough to snap or eat the tapes.