Dolby B incorporates a bit diiferent type of noise reduction then Dolby C.If I can recall on my old Marantz 4400 Receiver,Marantz would calibrate the receiver on Dolby B recording with a 400 HZ test tone.Dolby C elavates the noise band reduction up to the mid to upper mid band frequencies.Thus the noise reduction would be more beneficial in the upper band frequencies.In general Dolby B may reduce noise by 3 to 6 DB,and Dolby C may reduce noise by 10 to 12 DB at certain particular frequencies.
Nakamichi Dragon and other top of the line cassette players also utilize built in computers to auto bias the tapes for maximum noise reduction as well.
Nakamichi Dragon and other top of the line cassette players also utilize built in computers to auto bias the tapes for maximum noise reduction as well.