Bass cut at 80 hz

Is he cutting 80Hz specifically, or using a low shelf, or a high pass?

Cutting unwanted low end rumble is a good idea. The problem is, that a general rule like "80 Hz" is nonsense, because every EQ and filter is very different. For example, if you have a filter that has a rather small Q (or steepness) like 6db/octave you will influence frequencies that lie high above the desired frequency of 80 hz and you will probably cut the low mids that you want to keep. On the other hand a filter with a high Q like 24db/octave it might sound very unnatural.

You can use the Studio EQ in the KPA to try it for youself. Set the low frequency to minimum and the low cut to maximum. Since the frequency is set so low, you probably won´t hear any change. Now slowly increase the frequency until you begin to hear a difference. It should tighten up the low end without loosing too much sound. Also keep in mind that sincle coil guitars do not need so much low end tweaking as guitars with high ouput humbuckers.

You can do that with the wah high pass stomp.

yes yes yes

http://www.wikpa.org/Wah_High_Pass