I'm kind of curious why people are using such powerful solid state amplifiers for such efficient speakers. Do the speakers need to play at a minimum loudness level to sound good? I was thinking (from memory) that these speakers were something like 96dB efficient and an easy 8 ohms. Maybe I remember that wrong. The website doesn't work on my iPad so I can't check it out. I'm sure someone can straighten me out on the facts.
I'm only asking because I thought that these would be great speakers for single ended triode amps, say 300B or 211 amps of 8 to 17 watts. Or maybe a small and simple pentode amp, like El84 or El34. Anyone using anything like that?
This is a very good question. Just as there are many reasons for using efficient speakers beyond matching with low power amps, there are also many reasons for using high power solid state amps beyond needing power to drive the chosen speakers.
One is that usually there is more extension and control in the bass with powerful solid state than with tubes, (please note I said "usually" as in everything in audio there are always exceptions). Of course a primary reason is dynamics. Even with a fairly efficient speaker, having amplifier headroom can open up the dynamic range. I have a link on the site to a PDF from Musical Fidelity about amplifiers and dynamic range. Imagine you are listening on my speakers (95db-98db 1w/1m) and the amplifier is running at about 5 watts when there is a sharp hit on the snare drum and you need more. In a really well recorded piece with little compression the attack on that snare may be ten to fifteen db higher than the ambient level. That means for that moment you need not 5 watts but 50-200 watts. Granted a really good tube amp will give you a LOT more than rated power for those split second dynamics but if your taste runs to well recorded music with percussion and you like to turn it up then there is a reason for all that headroom.
There are of course many reasons for each type of amplifier and it really revolves around personal taste but having efficient speakers just opens up the possibilities for all kinds of amplifiers.
To answer the question, the speakers are very consistent in their sound at any volume level... they do not NEED to be played loud.
I have people using these with flea power SET and with huge Class A, the speakers work very well with both.
One of the primary reasons for designing with efficient speakers is that they are FAST and effortless, that has always been the real beauty of horns and other efficient designs. An amplifier doesn't drive them, it unleashes them. With that speed and ease comes the subtle harmonics and trasients which to my mind are the life of the music.
I know I got a little windy here and I hope that wasn't at all pedantic?