|What kind of tape recorders are the best: cassette recorders or the ones with bigger spools? — HB, Stde, Sweden
The audio quality of analog tape recording improves as the tape moves faster past the recording and playback heads. That's because the faster tape motion spreads out the magnetized regions of tape over greater distances on the tape's surface. A cassette tape moves so slowly that oppositely magnetized regions are often bunched tightly together and they demagnetize one another. This demagnetization produces high-pitched noise in the recording. In contrast, a reel-to-reel tape that moves rapidly past the heads has magnetized regions that are widely spaced on the tape's surface and that are much less susceptible to demagnetization and noise.