It would be possible if the real power consumption of both devices added together is less than 150 mA. Both manuals say it needs a 12v 150 mA power supply, but they may actually consume less.
However, from the spec sheet of one of the devices. http://www.behringer.com/assets/MA400_P0491_S_EN.pdf
That says "power consumption" of about 2 W. Watts = Volts x Amps so 2 = 12 x .166. It looks like that one device takes up to 166 mA from the specification, so that seems to indicate that this one unit will need the full power supply output of 150 mA.
Specs could be approximate, but I would say you need to keep 2 power supplies or find a single 12v supply that offers 300 mA or more.