AU Lab n-band equalizer q defintion

Hello.

A question specific to AU Lab on Mac OS...

Is the Q factor utilized by the parametric filter type within the AU Lab N-band equalizer (AUNBandEQ) constant, or proportional?

In other words, for a given quality factor setting, does the bandwidth vary as the gain is adjusted, or is it fixed? Both of the following are common, but I'm hoping for the second definition:

Bandwidth = centre frequency/Q

Bandwidth = sqrt(gain)*centre frequency/Q

(I've seen other definitions as well, but these appear to be the most common.)

Just playing with it via the GUI, it appears as if the EQ plugin uses a constant Q definition, but I'd appreciate a more definitive answer.

Thank you!