QSC Audio KW181, KW152, KW153, KW122 user manual High-frequency EQ, Subwoofer Polarity

High-frequency EQ

On the KW122, KW152 and KW153 there are two high-frequency settings. From the factory, the switch is set to FLAT. This means that the loudspeaker system is producing a flat response through the vocal band. This is the standard setting for most applications.

In voice-only reproduction, the switch can be set to the VOCAL BOOST setting. This will engage EQ that gives a stronger presence for vocal intelligibility and presence. It is generally not recommended to use this setting when playing full-range music through the system.

KW122, KW152, KW153 High-frequency EQ Switch

EN

Subwoofer Polarity

Polarity (sometimes improperly referred to as phase) refers to the voltage of an input signal and whether it is a positive or negative voltage at any given time. In most cases a positive voltage causes a woofer cone to move forward with respect to the cabinet orientation, and a negative voltage then moves the woofer cone backward. Most importantly, speakers reproducing the same signal or signals that are adjacent in frequency must have the same polarity to get the maximum output. This is most important for low frequencies. Polarity can be altered by incorrect wiring or mixer control settings.

The KW181 provides a polarity switch to correct any wiring or mixer setting errors. The polarity switch is set in the NORMAL position from the factory.

When using the KW181 with KW Series full range loudspeakers, NORMAL polarity will result in the best bass response if the full range loudspeakers are sitting on or very close to the subwoofers. If the subwoofers are some distance away from the full range loudspeakers, polarity change may be of benefit. Start with all subwoofer POLARITY switches in the NORMAL position. Then, with the system at or near expected operating levels, change the polarity of each subwoofer individually. Walk around the venue and assess the overall bass response. Select the polarity that results in the best overall system bass response.

KW181 Polarity Reversal Switch

When using only one KW181 and connecting a LEFT and RIGHT stereo signal, start with the polarity switch in the NORMAL position. With the system at a reasonable level, change the POLARITY switch and evaluate which polarity results in the most low-frequency output.

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