TDK SM or SMX?

[El Barto]

Is there really a big difference between these two types of cassettes? Will I notice better sound with SMX? And what length of tape should I use on a cassette 8 track? What's the longest I should use? 90 minute? 120 minute?

[virtual.ray]

If you run tape at high speed (3 3/4 ips)you may not hear a difference in sound but the more expensive one has a better shell and mechanism and should hold up better over time.I would stay with either 60 minute or 90 minute length.Multitrack recording is different,you're gonna do a lot of rewinding and stopping and starting of the tape so go with the good stuff so your hours spent working will be well preserved.