+1 Cleeds. Exactly correct. The deck has to be correctly biased for the specific tape, the user has to have the correct equalization selected for the tape formula and the record head has to be correctly aligned or it won't work properly. I have cassettes I recorded in the early 80s that blow away anything digital to this day. Took a lot of work and $$$ to make it happen, but the results spoke for themselves.
Dolby NR encoding - did it ever work
What I mean is, if you record something with Dolby NR engaged, the sound should have the high frequencies boosted and the noise floor unaffected during playback without Dolby NR engaged. I had a Kenwood tape deck that would reduce the noise floor during recording, which isn't right. I am considering buying a new, collectible tape player.