TheIW-100WVand theXL-100are 100 watt indoor in-wall volume controls. TheIW-IMP100WVandVX-100are impedance matching versions of these same controls that are configurable for maintaining a safe system load when multiple controls and speakers are connected. These controls utilize autoformers to efficiently transfer the power from amplifier to speaker. Autoformers are the electrical equivalent to a gearbox in an automobile with each of the 12 volume positions a different gear. It is common to locate these controls in the same room as the speakers.
The VX-100 lets you have music throughout
your home. You can have speakers and a
volume
control in one room and have the rest of
your system in another.
Impedance Matching Autoformer 
