What DC power supply to use on motor driver?

The Falcon Laser machine has a DM580s driver for the Y motor(573s20). We did some testing on the voltage and current of the driver's input. We can see as the speed increases, the current and power drawn will increase, then decrease, then increase again. The 48V input draws more power than the lower voltage. We did not test the motor torque, but even the 24V has enough torque for normal usage. The Falcon normally uses the 36V power supply.