As good as some of the higher end compact cassette machines got, the pre-recorded cassettes always suffered from the limitations of the high speed duplication process used to record them. If you were making your own recordings, you could achieve better quality, but still, without Dolby B, C or the DBX noise reduction circuits in the better machines, tape hiss was audible. Those noise reduction systems improved things, but now one needed to pay attention to what tape the machine was optimized for. Some machines even had bias adjustment features, but it wasn't long after that, that CD's started to make their debut. Sony recognized the limitations of the compact cassette and introduced a product called the L-Cassette which used 1/4" tape and ran at 3-3/4 i.p.s. The L-Cassette was nearly the size of an 8-track cartridge and improved the signal to noise and frequency response limitations of the compact cassette, but pre-recorded L-Cassettes were never made and the format died an early death. I often wondered if Sony introduced that format 5-10 years earlier, if it might have enjoyed greater acceptance.
