Two ways are fine for small loudspeakers, but if you want deep bass, then the bass driver has to be large, (or use multiple units). A large bass unit will start beaming at a fairly low frequency, generally below that at which most tweeters are happy. That means a mid-range unit, which itself will start beaming and breaking up at the top of its range, so needs a tweeter. Hence, three ways is about the minimum for deep bass and smooth treble.
A Tannoy DC has limited dispersion, which is fine if that's what one wants, but it also has a fairly ragged HF response, so it far from a neutral loudspeaker. They can be very pleasant to listen to, I'm partial to a large DC myself, but they're hardly neutral, analytical instruments, which is what I require in a loudspeaker.
Thanks for the rep Pete back atcha 😀 You lucky bugger SJS Arcadi eh!
I replaced mine with an Esoteric C03 & never looked back as it is dual mono with gain adjustment on each connection which sortted my issues with various amps I own.
If the digital scales are not purpose built for tracking weight I have found them to be unreliable, and you may be tracking far to light, which would cause the symptoms you describe. Also have you set the overhang in the headshell correctly. Do not worry about adding a little more tracking weight, to little weight causes more damage than tracking at the maximum weight allowed.