Soundlab speakers with sub woofers?

ZD, yes, that all sounds right to me, with respect to the sonic performance of the solid state amp in itself. That is a separate issue, of course, from the question of how suitable the amp may be for use with a speaker which doesn't want to see constant voltage as a function of variations in load impedance.

Also, although you are referring to solid state amps, I'll add that in the case of tube amps having output transformers a caveat might be that if there is a substantial mismatch between load impedance and the impedance the output transformer tap being used is designed to work into, there may be a significant increase in distortion (as well as a reduction in maximum power capability, relative to what it would be if that match were optimal). Ralph can most likely provide a better quantitative perspective on that than I can.

Best regards,
-- Al

On most tube amplifiers its a good idea to try the Sound Lab on the various taps of the output transformer to see which works best.

Some transformers can ring if not properly loaded- so if you are on the 8 ohm tap and the amp is playing into a 30 ohm load on a bass note, you may get increased distortion (lower ordered harmonics) that might cause the amp to sound warmer than is actually correct. It depends on the design of the amp as to whether there will be a significant loss of power with such a mismatch, but IME usually the loss of power is slight. If the amp has negative feedback most of the distortion will be controlled but that can be a double edged sword as with more feedback comes a greater tendency to behave as a voltage source.

With our MA-2 (about 70% of our production in the last 20 years are driving Sound Labs) there is also a slight loss of power into 30 ohms (about 10 watts), but distortion is actually reduced into the higher impedances.

In short, this is a speaker that benefits more than many box designs from a slightly higher output impedance in the amplifier.

I heard a pair of Soundlab Ultimate 1's driven by a pair of CAT mono block amps in a fairly large room of an audio friend.

Absolutely no need for one or more subs.

I have owned several other stats, and even tried the ML Depth sub with CLS11z when I had them.

I preferred the CLS without the sub.
Less bass wallop, but also a more unified sound.

When I ran a full out HT set up with two pair of CLS and the Theatre centre channel the Depth came into it's own on the .1 end of things.

I also had two Velodyne ULD 12 on a pair of Quad 63, that added more bass but again you gain in some areas and lose in others.

If your stats go down to the mid 30's as the ones I have now do(Acoustat 3, servo amped)I don't think you will need to add a sub.

Hi just came across this post today.
 I am using janszen zA2.1 with a Sumo Delilah X-over (no EQ, internal switch set to use external x-over) and SoundLab A-3s and KLH Model Nines. The Nines are faster than A-3s and mesh extremely well with the superb dual 7" woofers in the zA2.1. In my opinion the Nines sound better than the A-3s