A true mono cartridge, which has only one coil, can have vertical compliance without generating any noise as a result, if there is no mechanism to transduce vertical movement into an audio signal.
My point exactly. Vertical compliance by itself does not disqualify a cartridge from being "true mono."
Another issue, I much prefer 2-channel mono over the idea of using only one of two speakers when listening to mono. Old habits die hard, I guess. But this is why I personally have no interest in ancient true mono, 2-pin cartridges from the 50s. (While I am a big proponent of vintage stereo cartridges.)No argument here! I *love* mono played through two speakers, esp. with my Maggie dipoles which energize the entire room. It's also a great way for tuning the system. If your mono signal is dead center between the speakers and you get a sense of depth, you're on the right track.