A method of operating a quadrupole device is disclosed. The method comprises operating the quadrupole device in a first mode of operation, wherein ions within a first mass to charge ratio range are selected and/or transmitted by the quadrupole device, and operating the quadrupole device in a second mode of operation, wherein ions within a second different mass to charge ratio range are selected and/or transmitted by the quadrupole device. In the first mode of operation, the quadrupole device is operated in a normal mode of operation wherein a main drive voltage is applied to the quadrupole device, or in a first X-band or Y-band mode of operation wherein a main drive voltage and two or more auxiliary drive voltages are applied to the quadrupole device. In the second mode of operation, the quadrupole device is operated in a second X-band or Y-band mode of operation wherein a main drive voltage and two or more auxiliary drive voltages are applied to the quadrupole device.