MB sound systems were crap until Bose came along. A W140 with Bose is the first MB that has a good stock system.
The new ones have awsome sound systems.
I guess for its day Becker was pretty good, back in the 80's people didn't expect the kind of sound that cars today are putting out.
The problem with the older cars is they only have four speakers!
So you have to work a bit to get modern S class sound out if.