> *How does a power transformer favor a speaker impedance load?*

At full power, the amplifier takes some voltage and draws some current. This is nearly proportional to load impedance. For totem-pole class B OTL, the power amp "acts like" a resistor about 6X the load impedance.

Check: for *example*, 48V (+/-24V) rails will support near 32 Watts in 8 Ohms (16Vrms, 45Vpp) and suck about 1 Amp. Power input is 48W, output 32W, efficiency 66%, which isn't ideal 78% but is very real-world. Apparent resistance is 48 Ohms which is 6X the 8 ohm audio load. The ratio is well above "1" because the two halves work alternately, peak of a Sine is well above average, and there is some pi in the mix. (You could derive this exactly, but I lost that matchbook, and in practical work "6*Rl" is close enough.)

I see four speakers and these days they are often nominal 6 Ohms. This suggests a single amplifier and 1.5 Ohm loading to get all the juice out of that iron. (I'd probably run two chips and two 4r speakers; the system was designed for lightly-clipped music, not HARD-clipped.)