Galaxy Audio POWERED MICRO SPOT - Manual (Page 4)

Page 3
Z=
Z x Z
1 2
Z + Z
1 2
Where Z1 is the impedance (or ohm rating) for the first speaker, Z2
for the second, and so on, for every speaker in the chain. This
equation calculates the total impedance of the speaker system,
which should
NOT be lower than the minimum impedance rating of
the amplifier.
EXAMPLE 1:
For one pair of speakers use the short form of the equation: the
product of the two speakers divided by the sum of the two
speakers is equal to the total impedance or the equivalent
impedance of the speaker system.
Z(Total)=
1
1 1 1 1 1
___
+
___ ___ ___ ___
+ + +
Z Z Z Z
2 3 4 N
Z
1
OHM’S LAW AND THE HOT SPOT
All unpowered HOT SPOTS have a 16 ohm impedance, and like
most professional-type speakers have jacks which are wired in
parallel (meaning the signal can travel into one jack and out of the
other).Think of each speaker as a “load” added to the amplifier.
The greater the number of speakers, the heavier the load. Adding
too many speakers can overload the amplifier, causing it to
overheat and distort. If the amplifier begins to distort, or if it
becomes hot to the touch, disconnect any extra speakers. One
easy way to determine the load on the amplifier is to use Ohm’s
“ law, which states: “The total impedance of N speakers in parallel is
equal to the reciprocal of the sum of the reciprocals. In equation
form:
This equation may be used to calculate the equivalent impedance
for additional speakers in two-speaker increments. Determine the
impedance of the first two speakers, substitute Z total for Z , and
include the next speaker. Repeat the process until all speakers
have been included. The result should be the same as with the first
method. A word of caution: polarity rules must be observed when
connecting multiple speakers. Polarity will not affect the Z, but can
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