Verifying Polarity

Incorrect driver polarity impairs system performance and may damage the drivers. All Meyer Sound loudspeakers are shipped with the drivers in correct alignment. However, if the driver or circuit wiring has been removed or disassembled in any loudspeaker in a system for any reason, check the polarity between adjacent loudspeakers and between drivers in the same cabinet.

Polarity Between Adjacent Loudspeakers

Use the following test procedure to verify the polarity between adjacent loudspeakers of the same type:

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.

Top view of adjacent speakers with measurement microphone

Correct polarity causes	Opposite polarity causes
acoustic addition	acoustic cancellation

The polarity is correct if the frequency response remains constant with a significant increase in amplitude. Broadband cancellation (decreased overall level) indicates polarity reversal.

Driver Polarity in the Same Loudspeaker

Use the following test procedure to verify polarity between drivers in the same loudspeaker:

1.Place a monitoring microphone three ft from the front of the loudspeaker at the midway point between the low and high frequency drivers.

2.Connect a signal source to the loudspeaker and note the frequency response.

!Since polarity reversal causes excessive driver excursion at high source levels, use moderate levels when conducting this test.

Drivers with correct	Drivers with reversed
polarity cause acoustic	polarity cause acoustic
addition	cancellation

The polarity is correct if the frequency response is smooth through the crossover region (±4 dB 600 Hz – 1 kHz). Severe cancellation in the crossover region indicates polarity reversal.