The HyDrive HD112 and HX112 have an innovative dual voice coil design that allows the cabinets to operate at either 4 or 8 ohms impedance. These cabinets have a impedance selector switch on the rear jack plate.
If you are using a single speaker cabinet, and the amplifier has a minimum impedance of 4 ohms, set the HyDrive HD112 impedance selector switch to 4-ohms to get the maximum power from the amp.
If you are using two HyDrive HD112 together in parallel, for a total impedance of 4 ohms, or adding a HyDrive HD112 to your current rig, set the impedance selector switch to 8 ohms.
NOTE: Be sure to check the manufacturer’s recommended minimum safe impedance rating for your amplifier before setting the impedance selector switch to avoid any damage to your amplifier.