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Use the following test to verify polarity between high
and low frequency drivers:
1. Place a monitoring microphone 5 ft from the grill
frame, 24” below the top of the cabinet, at the mid-
point between low drivers (center-line of cabinet).
2. Connect a signal source to the loudspeaker and
note the frequency response.
The polarity is correct if the frequency response is
±
3 dB 500 Hz – 1 kHz. Polarity reversal is indicated by a
6 – 12 dB cancellation in the same range.
Polarity Between Adjacent Loudspeakers
Use the following test procedure to verify the polarity
between adjacent MSL-6 loudspeakers:
1. Position two loudspeakers adjacent to each other.
2. Place a measurement microphone six ft from the
speakers on the axis between them.
3. Connect a signal source to one speaker and note the
frequency response and overall level.
4. Apply the same signal to the second speaker with
the first speaker still connected.
The polarity is correct if the frequency response remains
constant with a significant increase in amplitude. Broad-
band cancellation (decreased overall level) indicates
polarity reversal.
Phase Poppers
We do not recommend using phase poppers to analyze
driver polarity. The phase response for all drivers varies,
to some degree, over the frequency range in which it
operates. Since phase poppers do not discern variations
in phase with respect to frequency, they do not provide
accurate information about the phase response through
the crossover.
Phase poppers are, therefore, not useful for performing
phase measurements on individual loudspeakers or full-
range sound systems containing one or more crossovers.
If necessary, apply a phase popper only to loudspeakers
with identical drivers without a crossover, and check
the overall system phase response with a frequency
analyzer and/or listening test.
