Audio Equipment

Speed Accuracy

Cassette machines are especially prone to speed variation problems. These variations can occur from tape to tape or even within any given tape. The age of the recorder, calibration, temperature, and the quality of the shell that houses the tape all factor into the speed accuracy issue.

If your recordings are to be used for any kind of scientific analysis work, then knowing the exact speed is a must, as tape speed directly affects how accurately the signals recorded can be replayed on other equipment.

An essential tool to help solve this issue is the pitch pipe or tuning fork. If a known pitch, e.g. A-440, is recorded every so often along the tape, it will be possible at a later time to adjust the playback speed of the recorder to match the original recording. Pitch pipes or tuning forks are available from most music stores and are not very expensive.