Merlin TSM with Shindo 25 watt amp

FWIW, I am running my TSM's in a 16 x 13 x 8 room with a pair of Manley Mahi monoblocks. I never take 'em out of triode mode (20 watts/channel) and they play PLENTY loud for me! I've tried them in UL mode (40 watts/channel) and I miss that glorious triode midrange. Yes, it's a matter of taste, but in a medium small room, they'll go plenty loud on 20 watts.

The Merlin VSMs are more far more efficient than most people realize.

Compared to my 96 db sensitive Horning Perikles backloaded horns using Lowther DX-2 drivers, you definitely have to go up a click or two on the volume dial, but it's surprising how close things are in that regard.

Two moderately powered tube amps I drive mine with, a push pull 6AS7G integrated and a Dynaco ST70, provide more than enough power.

I don't think "loudness" should be the only criteria here. Although I've never heard the TSMs, the Devore Super 8s that I used to have were also 87 dB. Sure they played loud and I never had to crank up the volume too high, but although they are a fine sounding speaker, I always felt that there was a little something missing... dynamics! I think this is where higher efficiency speakers really shine with lower powered tube gear. I later moved to Coral Beta 8s that are 100+ dB and they are a bit more snappy and have more bottome end. IMO they're a great match for my Shindo Montille amp. Just something to think about.

m8, lower efficent speakers can be as dynamic as heck if they are extremely linear and continuous sounding. in this way you can hear the correct balance between the micros and macros.
jmtc.
bobby at merlin

I have used TSMs with a Sugden A21a 25W amp, and a leben CS600 30W amp both in a 14 x 12x10 room.power has really not been an issue so long ( i sit 8 feet away)