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Multiple Speakers
How many speakers may be attached to the
Duet Plus?
The answer depends on the power required,
speaker impedance, and wiring resistance. The
Duet Plus was intended for ONE speaker, typically
a horn speaker located on a warehouse, machine
shop, or outdoors or a wall baffle cone speaker
for quieter indoor areas. This assumes of course
that the speaker in the Duet Plus does not provide
sufficient volume for the application.
The Duet Plus is fully protected against short
circuits and will automatically reduce output
power if the output is set too high for the speaker
load impedance.
The facing diagrams show maximum warble
power capability with 8 Ω speakers, 24 Vdc power
supply, and no wiring losses. Output capability is
reduced by approximately 30% for voice paging
to avoid clipping.
Wiring resistance is critical with low impedance
loads such as 8 Ω speakers, and even more
critical with 4 Ω loads (two speakers in parallel).
With a 4 Ω load, 50% of the power is lost after 75
feet (23 m) of 24 gauge wire. Use any available
spare wires in parallel to reduce resistance.