I've been toying with older recording technologies lately, and have been wondering some things about the medias I'm experimenting with. Since I am mostly messing with microcassette voice recorders at the moment, I have been wondering exactly what the tape is capable of storing if I was to modify my recorder to send a straight 20-20K unfiltered to the head, then whatever was on the tape to the line out jack. Would they sound ALMOST as good as a cheap cassette with some phasing and other distortion? ...or am I pretty much hearing all the tape can give me as is?

BTW: I am also trying to collect and restore other recording technologies, especially old tapes and wire recorders for the same purpose of hearing what they have to offer.

 

An ordinary size cassette deck got improvements over the years to produce almost hifi sounds. A micro-cassette unit was a low-fi voice recorder/player.

Tape players use NAB equalization that boosts high frequencies and cuts low frequencies during recording, then cuts high frequencies and boosts low frequencies in high speed players on playback. Regular size cassette players also boost high frequencies during playback.
The tape in a cassette player runs at a slow speed then high audio frequencies are limited to maybe 12kHz on an expensive cassette tape deck to maybe 5kHz on a portable micro-cassette recorder/player.
The tape is not wide which produces a lot of noise. Dolby noise reduction was used to reduce some noise on expensive cassette decks but not used on low-fi portable micro-cassette recorder/players.

An ultrasonic bias was added to regular cassette (not on all micro-cassette) recorders to reduce severe distortion.
Your idea of not using equalization and bias would make awful sounds, worse than a cheap AM radio.

 

See the attached.

 

The 1972 article showed pretty good fidelity when a reel-to-reel deck was using tape that was much wider than a micro-cassette for reduced noise and at a tape speed 16 times higher for a fairly good high frequency response.

I worked for Philips when they invented the compact cassette and played with making mine almost hifi.