This is a truly amazing video and also a perfect example of why I love the internet. I just learned a crapload of stuff about cassette tapes that nobody has ever mentioned or ever told me before. I was part of the generation that saw the end of cassettes and the introduction of CDs and dabbled a bit in recording some of my own mixtapes onto cassettes. It was a process I enjoyed as I sat in front of a stereo and waited for songs to end so I could press the pause button to stop recording between tracks.
Anyway, that's another story for another time. This video is incredibly fascinating because it shares a wealth of knowledge on cassettes and the different types of tape you could buy and record on. As it turns out, I was almost always using the cheapest type of cassette tape available -- but I guess that's ok because I was never recording on a very sophisticated machine. But for anybody who was into high-end audio at this time, they would have almost certainly had metal tapes with a cassette deck that included various Dolby noise canceling technology (the best being "Dolby S").
Up until now, I've always considered cassette tapes to be an inferior technology to CDs, but as this video shows, with the proper equipment, a cassette really could have sounded quite close to CD quality. In the end, it just wasn't practical or affordable to record on the best cassette tapes so the technology ultimately lost to CDs. But if anybody ever tells you cassettes were garbage, maybe you should guide them to this video and ask them what type of cassette they listened to and recorded on. Apparently, it makes a world of difference.