The Morels are 90db sensitive. I know of one guy using a 30w Cayin tube
amp with excellent results. He says that even the bass definition is superb
with the tube amp.
The Morels have a sound that is certainly defined by their tweeter. I think this driver is excellent and unique sounding, and I haven't heard a tweeter that sounds quite the same. For that reason I can only really compare this speaker to the GMA Europa's, which have the same tweeter.
There is this quality to the Morel tweeter that is definately prominant in both speakers; for instance a ride cymbal hangs in space exactly, very resolving and with a decay that just keeps going to the smallest possible drop of sound. I would say the same for vocals on up. I think the treble is a bit more resolving in the Morels though. And I feel that the Europas focus much heavier on the vocals (Roy would argue its my setup of course).
I also think the Morels have a larger sweetspot. From 10 feet away, I get that good lucky feeling 3 feet anywhere from center. This includes forward, backward, sideways, up or down. They are 74 iinches apart with a touch of toe in.
As with the Europa's, there is an ear filling quality. The speakers seem to cover you in sound even at low volumes. The Morels absolutely suck for background music; its a very penetrating 3 dimensional sound image that you must pay attention to if you are in the room.
Distortion is also very low, even at high volumes, and you can hurt your ears by playing too loud and not noticing. Clean and clear with a big fullrange sound.
btw, the Dennis Murphy mod is a must. Especially for $20 a pair. That guy is a saint.