MS Series Speaker Selector - Global Home Audio

The MS-Series of speaker selectors accommodates six, eight, ten and twelve pairs of speakers. The controls of the MS-Series allow you to play any combination of speakers simultaneously.

No Volume Variations Ever. The system directs exactly the same amount of power to each speaker regardless of how many speakers are playing.

No Ventilation Necessary, since the MS-Series incorporates autoformer protection, and no heat is generated by the protection circuits. As a result, the MS-Series can be placed in cabinets without ventilation or fans.

Impedance Indicating System

When purchased, this system is built-in and self-powered. It is a handy aid in choosing the best settings of the impedance matching rotary switch. A red and green light indicator on the front panel shows a constant indication of operating status. The amplifier is 4 Ohms or higher when the green lamp is lit, below 4 Ohms if the red is on. If red, simply rotate the matching switch CCW until the indicator turns green, and you are operating within safe parameters.

This indicator system is useful for maintaining maximum power transfer to the speakers in actual use. If this is desired, rotate the matching control clockwise until the red lamp comes on, then back off one position at a time until the green lamp lights. You will then be matched as closely as possible to 4 Ohms at the amplifier output, which is the maximum power transfer for the speakers in operation.

Note that this system derives its power from the left channel only, although impedance is measured on both channels. Also note that the red-green light indicating system is self powered and may flicker somewhat, especially if the driving amplifier is operating at very low power. Approximately 1 watt minimum is required to light up the system. When closely matched, the green indication may occasionally change to brief red flashes. This is due to nonlinear impedance characteristics of most speakers and need not be cause for concern. If the duration of red is longer than green, the impedance selector switch should be backed off one position or more until the green indication predominates.

Sonic Stabilizer

If purchased, this unit is also built-in. It is a high-pass filter that reduces very low frequency (subsonic) input into the impedance matching system, reducing amplifier over loading caused by very low frequency transients. This also allows higher power operation in the main audio spectrum without amplifier shutdown, even when heavy bass is present.

An additional advantage is that ceiling and in-wall speakers are helped from being severely damaged by subsonic bass and transients that can otherwise invert the woofer cones of this class of speakers, which are almost never properly baffled for very low frequency operation.