speakers with a "smooth" impedance curve


I had started a thread asking about speakers that are well designed for tube amps (I am currently using a Ming Da MC 34AB with 8 EL34 power tubes 75 wt/ch ultralinear; 40 wt/ch Class A).
There has been a consistent recommendation for efficient speakers with a "smooth impedance curve".

Any recommendations out there for some tower speakers in the less than $5000 price range with smooth impedance curves that are "tube friendly"?
rsasso
To Beavis

My current speakers have a nominal impedance rating at 6 ohms. I can't find an impedance curve on these speakers, but the manufacturer recommended the 8 ohm taps on my amp. I think the system sounds much better using the 4 ohm taps. The question is, if the impedance curve does drop below 4 ohms, does that strain the amp and risk damage to the amplifier?
>tower speakers in the less than $5000 price range

That was my price range 7 years ago. I bought Coincident Super Eclipse IIs in black. I have Welborne Lab 300B SETs. I love these speakers.

According to the manufacturer the load does not drop below 10 Ohms, and the sensitivity is around 93 dB/w/m. Your 40 watters would make the Super Eclipse sit up and beg.

Regards,
DeVore Fiidelity. I am running Gibbon Nines right now
w/ 75 watts. It is plenty of power.
Post removed 
I'm not really sure any of the above loudspeakers have a "smooth" impedance curve.

What's more, I'm less an adherent of this mantra than most. Tube amplifiers prefer higher impedances, and most tube friendly loudspeakers have far more wild impedance curves than the conventional wisdom of smooth impedance curve thinking would ever lead a person to believe.

Why? With most loudspeakers (multidriver and parallel crossover network), the requisites (a bevy of crossover correction/compensation circuits) to produce this desired smooth impedance curve do a lot more harm than good in terms of making the loudspeaker more friendly to a tube amplifier. Put it this way, in order to attain this smooth impedance curve, more crossover parts are required, and crossover parts act as speed bumps in terms of a tube amplifier putting power into a loudspeaker. Beyond that, such "correction" circuits rob the music of life, vibrancy, and immediacy, even if the partnering amplifier seems up to the challenge of blowing through those speed bumps.

As an alternative to seeking a smooth impedance curve, look toward loudspeakers that offer as simple a crossover topology as one can find, and several of the above loudspeakers mentioned above fit that paradigm.