This 4-zone speaker selector box gives you a centralized location from which you can turn zones on and off. An impedance protection switch, when turned on, sets the impedance at a safe level of 5.7 ohms, regardless of the number of speakers being driven.

Connect a stereo amplifier to the stereo inputs on the selector box using speaker cable. That powered signal is then available to the 4 speaker outputs on the selector box. Speakers can be connected directly to the speaker outputs, but more often they are first connected to a volume control located within the zone.

The impedance protection circuit can also be turned off when the selector box is used in combination with an impedance matching scheme. Impedance matching, as opposed to impedance protection, corrects for the fact that you are connecting multiple speakers to a single amplifier, by increasing the impedance back up to a safe level. This is done by setting impedance matching volume controls (the only kind we make) to an appropriate multiplier. We explain this in more detail in the volume controls section.

The benefit of using impedance PROTECTION, is that it allows you to safely turn zones on and off. The only downside is that the protection circuit has the effect of slightly limiting the total power output from the amplifier.

With an impedance MATCHING scheme, you get full power out of your amplifier, but zones can only be turned off at each of the volume controls.

Whether you choose to use impedance protection or impedance matching, a speaker selector box makes for a convenient connection point for expanding the number of speakers you can connect to a stereo amplifier.