Speakers for Gryphon Diablo 120

ProAc K1 should sound very good in that room.

Maybe Focal

@ullogu1 - It’s funny you happen to ask this question, as I just went through this myself. I saw a used Gryphon 120 come up for sale used from a dealer and I jumped on it. Initially, I paired it with my QLN prestige 3 speakers. The synergy didn’t work, as the Gryphon 120 has a dark character on the top end. 
 

I switched in my pair of Dynaudio Heritage Specials speakers and they sounded absolutely fantastic with the Gryphon 120 amp. The Dynaudio Heritage Specials feature one of Dynaudio’s top end tweeters, so there is a lot of focus on the upper frequencies. 
 

When I listen to that pairing, my urge to upgrade or tweak equipment sort of goes away. I’d read somewhere that Dynaudio tends to be synergistic with Gryphon. I was fortunate to have a pair of Dynaudio speakers, so I got lucky. 
 

Can’t recommend that pairing highly enough. 

@milpai - I’ve demoed some proac speakers. My sense is they don’t have enough treble energy to compensate for the dark nature of that amp. My two cents. 
 

Maybe try to listen British speaker, they tend to be very nice on top end .

Harbeth , Graham, Stirling