The primary (the bit that you plug into the mains) will be the series-wound 10-100-0-100-10-20 windings (think of each pin relative to the 0v point, with the pins on the left being a notional -, and the pins on the right being a notional +, then the left-most '10' is -10-100 (=-110) wrt to the 0v line, and the right most '20' is 100+10+20 = 130V, and the difference between these is 130 - (-110) = 240V. If that makes sense?

Then the secondaries, you have a 20-0-20 winding (essentially, a 40V, centre-tapped winding) and two individual 50V windings, which I guess is what you're looking to use. The problem is that this 50V is the RMS value of the AC output, whereas your DM542t - if these need a maximum of 50VDC, then the peak voltage from the transformer under no/low load is effectively 50 x 1.414 = ~70V (drop a volt over the bridge rectifier) and the smoothing capacitor would rise to this. This is likely enough to damage the drivers.

The problem is how to lower the voltage to a safe level for the drivers - which is a bit more complex than the bridge/capacitor solution proposed. Plus, if you're trying to drop say 25V from this you're essentially trying to dissipate a third of the power of the transformer somehow (i.e. big heatsinks = £££).

Do you already own the drivers?, if not it might be better looking for drivers that support 80V.