The impedance/power different will not be a problem. You could use a smps300r with the t3s, but 38V will probably not be enought to make the relays turn on. at least 42V will probably be required. Still, no harm of trying if you have both there, you can adjust the voltage up to the maximum, and maybe you reach ardoun 42V which could be enough.
about 7 years ago
I'm planning to use the T3S for an active 2-way speaker build. My idea is to put a T3S+SMPS inside each speaker: one channel will power a 4ohm 150W woofer, the other channel an 8ohm 20W full range driver. Will this impedance/power difference be a problem for the T3S?
Also, I already have 2 x SMPS300R 38V which I previously bought from Hifimediy. Will this SMPS have sufficient to power to drive the T3S in my setup? Or do I need the larger SMPS500R 48V?