Don,

You want to have that hi-pass filter switch engaged almost always, particularly if you are recording vocals with the mic. Put the switch to the right. The graphics mean the following: the straight horizontal line means no filtering is in place. The ramp up and to the right followed by the horizontal line represents the high-pass filter shape the switch employs, with the bend being at the advertised cutoff frequency. Sometimes the mic manufacturer will put the cutoff frequency right on the mic itself. The shape helps to communicate that it's not an absolute 'brick-wall' filter, but gradually decreases amplitudes of lower frequencies as the frequency goes lower.

Using that switch will help to cut down on any rumble that might come through the stand, help cut down on plosive low-end popping from 'p' and 'wh' and 't' sounds and the like. If you record acoustic instruments other than bass viol or kick drum, engaging that switch will help to reduce boominess from those instruments as well. When I record my acoustic guitars with my condenser mic, I engage high pass filtering on the mic (mine is a CAD M-177 with an 80 Hz high pass/low cut switch)

It's also good practice to engage a high-pass filter with a cutoff around 150Hz in any DAW software you might have - right at the front end of the signal chain. All for the same purposes as having the hardware switch available.

My Songs, photos, writing,etc.
My Sound Cloud