I think you posted this question on the Tannoy FB forum. Anyways, just be aware the GRF90 is a little different than the Prestige models above & below it. It has rear reflex porting, which makes for amazing bass output, but perhaps at the slight expense of the vibrant, sweet & rich midrange you’ll get with Kensington (below) or Canterbury (above). I’m basing this on my own experience with Yorkminster SE (GRF’s 12" predecessor which has the same acoustic configuration despite very different looks), plus user reports on GRF90 which are inline with what I heard in the Yorks.
The other Tannoys use front "vented" cabinets, which is really an "Onken" type configuration (multiple ports at various lengths to spread out the response). The Yorks still sounded great to me (compared to my Kensington SE at that time), but I wished for a sweeter midrange and so went to Canterbury SE as my upgrade at the time (and later Canterbury GR). The bass was amazing though - best I’ve ever heard in a Tannoy. Better than even Canterbury GR.
If I’d kept the Yorks, I would’ve looked for a lusher tube amp to sweeten those mids.
The premium 12" pepperpot driver gives you a sonic image that’s between that of the 10" and 15". The 15" Canterbury renders a very large-sized image with a lot of vibrance; it’s lush and warm and has fantastic midbass but roll soff before the very lowest notes. The Yorkminster (and therefore GRF90) goes deeper for sure. But there’s really nothing like the immersion factor of that 15" driver, which is why some Tannoy aficionados won’t accept anything smaller!
I am a longtime Tannoy fanboy, have 7 (or is it 8?) pairs now, and possibly won’t buy anything else for the rest of my life. So if I have a choice of GRF90 versus another brand? GRF90, for sure. But within the Tannoy line - I’m definitely choosing Canterbury first, then maaaybe Kensington.
These pepperpot models (Kensington, Yorkminster, GRF90, Canterbury, Westminster) are also very detailed (especially the 12") and very sensitive to gear partners! You do NOT want harsh / bright / etched components partnered to any GR series Tannoy - they are unforgiving to this. Tubes are always a good choice. These Tannoys should also be way, way more refined than Klipsch.
You will no doubt get recommendations to look at Fyne instead. But they are now very expensive and have abandonded some of the traditional features that made the top of Prestige line special: paper/pulp cones, treated textile surrounds, pepperpot tweeter with huge alnico "omni" magnet. I also vastly prefer the traditional styling of Tannoy Prestige cabinets to what Fyne is doing (even in their own Classic and Vintage lines). The GRF90 in particular is quite gorgeous! No Fyne looks half that good, IMO.
