NTi Audio XL2 Sound Level Meter - Manual (Page 86)

86
Polarity
Polarity
Polarity measurement is important in matching the left and right
speakers for a good stereo sound image. The polarity function
measures the polarity of cables, single speakers and speaker
cabinets. For testing, use the polarity signal provided on the
NTi Audio Test CD or the Minirator test signal generator.
The polarity of individual speakers or speaker cabinets might
change with the frequency. For example, the mid-range speak-
er polarity may differ from the woofer polarity within the same
speaker cabinet. Therefore the polarity detailed result page of
the XL2 displays the measured polarity of the individual octave
bands from 125 Hz to 8 kHz. This allows in-depth verification of
the polarity - frequency relationship.
Polarity is a simple test within the very com- •
plex science of signal phasing. Drivers, speak-
ers and crossovers all cause phase shifts of
the audio signal.
The polarity of various speakers within the
•
same cabinet may differ by design!
Polarity testing is useful for checking the cor-
•
rect wiring of similar speaker systems.
Positive/Negative Result Page
1
2
4
3