Glad this is on a different thread....
Marco, the very first Tannoys I ever heard were the Chatsworths and Lancasters (at Radiolux in Watford, before B&O took over in that shop and just before KJ Watford took over all the better HiFi agencies from them). I remember the bass being very good, but the comments on the slight "sting" remain - this is the pepperpot and one of the things Tannoy fixed when the "Tulip waveguide" came in.
We had these two models very briefly at KJ for a month or two before the HPD series came on song, with much improved visuals (IMO) and a beefier bass and higher power handling (I read that the HPD drivers went into the last "old" range, so I may just have been listening to these drivers all along, I don't know...)
Whatever, these old speakers (if working properly) sound best on valve gear, rather than the brightly toned Crown D150 which I believe Angus MacKenzie used in his controvercial 1975 'Choice speaker review compilation.
Whatever you go for, the SP100's are damn fine boxes, with that full bodied power that characterises bigger speakers. Don't expect the pre-HPD Tannoys to have as much warmth, 'cos efficiency apparently came before bass extension on this era's products.
Regarding Lockwood Tannoys, I've been informed by at least two engineers who used them that they weren't up to much by the end of their lives - far too much cabinet colouration I understand. I suppose that if the boxes could be beefed up along modern thinking, you could get something really special..
Tear down these walls; Cut the ties that held me
Crying out at the top of my voice; Tell me now if you can hear me