QSC KW181 subs

I just finished a fashion show where I used (4) QSC KW181 single 18″ subs in addition to the venue’s Meyer Sound 700HP dual stacks for low end. During the setup it was discovered that one of the Kw181 cabinets has an issue. Today while I had a few spare minutes, I measured the (3) functional cabinets to verify they match and also as a baseline for verifying the malfunctioning cabinet after it is repaired.

QSC KW181 specs
QSC KW181 rear panel

Here are (3) overlapping traces with the mode switch on NORMAL.
QSC KW181 3 normal

Here are (3) overlapping traces with the mode switch on DEEP.
QSC KW181 3 deep

Here is a comparison of the same cabinet with the mode switch in both positions (NORMAL & DEEP).
QSC KW181 Normal & Deep mode

Note that when the polarity switch is reversed, the frequency response (measuring only one cabinet at a time) is unchanged but the phase response has rotated 180 degrees.
QSC KW181 plus & minus polarity