Is this enough power?

The phase angle is not a single number or a set of numbers. The data will be in the form of a frequency response graph, but with + and - phase angle on the vertical axis. Stereophile prints such data on the same graph that plots impedance at various frequencies. What makes a speaker difficult to drive would be an extreme phase angle (e.g. -45 degrees) at a point where impedance is at its lowest point, and particularly if such combination is at a frequency with a lot of musical energy (e.g., 80-200 hz).

Fortunately, reports like that of Stereophile, will not only provide data but an interpretation of its meaning so you don't really have to know how to read the graphs.

My guess is that 30 watts may work, provided you don't play the system at really high levels. For reasons I don't quite understand, I find that distortion from a shortage of power will be most evident on works with a large chorus. At a subjective level that does not seem that loud, a work like Rachmaninov's Vespers may begin to sound distorted if your amp is not fully up to the task (maybe its because human hearing is most sensitive and tuned to the human voice). If you get a chance to try the amp, bring along such works.

One of the advantages of a good SET amp is that they are quite musically satisfying and sound right at lower volumes so you probably would not really need to push them that hard. I personally don't mind trading off the rare times when I really want to play the system at extreme volume in order to get the desirable characteristics of a good amp for 99.9999% of the time.

Good, question--but YOU, are the only person that can answer this question. It works for ME, on paper...but that doesn't mean you'll be satisfied.

Good listening,
Larry

Thanks again for the explanations. I finally found a graph with phase.

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.

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

If a trial listening period for the amp can be had.. there's your answer.

Go with Al's comments... and later on... get one more amp, or more sensitive speakers..

Maybe you could also enclose that room with pocket doors or a pre-hung one andd a little build up around it... Otherwise, you're actually filling sound into the whole of the total cubic feet of the entire spaces. Listening area, AND kitchen area.

My situation (roomwise) was similar a while back. I've since closed off my room for a more dedicated listening - vviewing arrangement. I had pocket doors separating the kitchen from the living room, and a pre-hung 3/0 closing off the hallway to the rest of the house on the opposite side of the room. the room is roughly 14 x 21 x 8.3 with a gently sloped ceiling.

It helped the bass out tremendously. Imaging and separation too. Night and day diffs for viewing.

I ran some higher eff speakers with about the same sort of imp curve, roughly, off my 4 ohm tap on my 120 wpc monos... making it/them output half of their power at 60 wpc. Never listening to exceptionally high levels (avg low 90s) regularly, with occassions running them at the high 90s and never noticed any issues.

The info Larry and Al have given is key and prudent as well as accurate I'm sure.

the full realization of musical enjoyment comes from having a system which can reveal the honesty of its emotion and it's voice. Meaning, you might want to consider some nearfield listening situations. Getting closer to the speakers with your chair.

Ultimately I reverted back to the 8ohm taps and never looked back. the 4 Ohm taps yielded a warmer softer more romantic presentation... and the 8s showed a brighter, fuller, exceptionally more dynamic face of the music. Including better bass. Much better bass.

So as Larry said, the presentation might be alluring enough to offset a desire to raise the fun knob...

I feel often that we tgotta make compromises or replace things we may not want to in order to gain that which we seek, better. So if you love the amp... or love the speakers ... shuffle off the one you don't love quite so much down the road... as I'm figuring you ain't married to either one... possibly the amp ought not be bought unless the idea of new speakers is on your horizon.

Either way.. good luck.