You aren’t far away from me Alan ... you are welcome to drop in and hear what properly sorted Tannoys can do. And yes they still do room filling scale at modest volumes. As has been suggested, something to do with driver area I suspect. That’s with (currently) 35w of Radford STA25.
Main: Speakers 'RFC' Tannoy Canterburys / custom crossovers; Amp - Radford STA100; Pre EAR 912; Vinyl: Thorens TD124 MkII + Ikeda IT345-CR1 / Ortofon 309 Limited tonearms; Cartridges Stereo - Miyajima Madake, Ortofon SPU Royal N + Shure M3D Jico stylus; Mono - Miyajimas - Zero 0.7, Premium 1.0 retipped by Ana Mighty Sound bamboo cantilever, Spirit '78' 3.0 conical from Ana, also vintage GE VRII, Shure M44 strapped for mono with several Expert Stylus conicals for different eras of 78s; Phono stage and SUT from EAR 912; Esoteric Sound Re-Equalizer for equalisation of early mono and 78, switchable in from tape loop; Digital: Audio Note CDT2/II transport, heavily modded AN Kit DAC + Mutec MC3+USB.
Study: Speakers - Tannoy DC6; Amp: Duncan 'Tuberhunter' 200w class D; preamp - Pass DCB1; Vinyl: Garrard 401 with AT1503 tonearm and vintage SPU-GE; SUTs - Ortofon 2-15k & Bob's Devices; Phono Stage: Schiit Mani; Digital - Trichord Genesis III CDP + Arcam rBlink; Schiit Multibit DAC.