Is this enough power?

A key factor is the dynamic range of the music you are listening to (the difference in volume between the loudest and softest notes). You mentioned listening to classical music. Well recorded, minimally compressed classical symphonic music can often require 1,000 times as much power on brief peaks as on soft notes (1000x power = a 30db difference in volume).

So I would expect, for instance, that the system would have problems dealing with the bass drum on many of the older Telarc recordings. Likewise for some (many?) well engineered symphonic recordings on other labels.

Jazz and chamber music I would expect to generally be no problem.

Regards,
-- Al

I'll add some personal experience to my earlier comment. During the 1990's I was using 90db speakers having easy to drive impedance characteristics. In addition to some high powered solid state amps, I also used several different high quality vintage tube amps in the range of 20W to 60W, including Marantz 2's and 9's among others. This was in a 22 x 13.5 x 8 room, with a listening distance of 11 feet.

Recordings having either narrow or what I would characterize as moderate dynamic range, including many symphonic recordings, could be played with any of those amps at much louder levels than I or most people would want to listen at. However, occasional brief peaks on many symphonic recordings on labels such as Telarc, Sheffield, Reference Recordings, etc., could easily clip the amps that were in the 20 to 30W range. Using the Marantz 2's in triode mode (about 20W, from push-pull EL34's), a few recordings could actually arc the tubes, producing a bright blue flash.

So I guess the bottom line is that you'll be fine with most recordings, but not all.

Regards,
-- Al

Looks like the lowest phase angle is approx. -40 degrees at 30Hz where the impedance is 10 ohms. Other than that dip, the phase angle is above 0 degrees.

From what I understand from the above posts, this means this should be an easier speaker to drive and that the 30w of SET should be enough.

Have also found that most tests show that the speaker is 90db/2.83V/1m. Maybe the manufacturere specs are conservative.

I would still suggest caution before reaching that conclusion. Given that the speaker's impedance is 4 ohms below 1kHz, its efficiency in that region (where most of the power is typically required) is only 87db/1W/1m, because 2.83 volts into 4 ohms corresponds to 2 watts.

Assuming that you are referring to dynamic (non-planar) speakers, it can be calculated that 30 watts into each of the two speakers corresponds to a 95db sound pressure level at a distance of about 10 feet. As I indicated earlier, that should be good enough for most recordings but not for all.

Regards,
-- Al