A question about Tape Sound

I recently watched a nice video about the Tape and how it was invented. The fact that at the beginning sounded so bad that they had to abandon the idea of this medium until many years later someone (sorry I don't remember the name now) figured it out that if he applied a BIAS sound to the signal the quality would improve.



Now I recently was recording staff on a reel to reel and I was wondering where the nice sound comes from.



I always thought that it was a physical thing of the tape itself who made the sound nicer, but listening carefully in my mind I asked this:



This compression and saturation tape is known for, is it due to the physical medium (the tape itself, the ribbon) and the way it memorize the sound or is it coming from a compromise to be able to write properly on the medium that involves (maybe) compression, HF limiting and saturation to have a decent level?



Kind of how dolby system works for denoising (compress/expand)?



I mean is the sound coming out processed by the tape itself or is it modified to be able to get the best out of the tape?



Sorry if I'm not that clear I try to express myself.



What I mean is Is it the fact we writing on a magnetic thing that alter the sound? Or is the sound altered before and after to optimize the magnetic ribbon?



Thank you :)

A question about Tape Sound