Determining Your Setup
The "Setup" filter helps you to focus on those presets best-suited for how you use your Axe-Fx.
FRFR/Direct presets (like all of the Factory presets) are designed for "full-range flat-response" systems such as studio monitors, PAs, headphones, etc.
Pwr. Amp + Cab presets use real power amps and guitar speakers.
4-Cable Method (aka :4CM") presets require a special setup with connectors both in front of and in the effects loop of a real amp.
Fx Loop presets in the loop of a real amp. A loop may be SERIES or PARALLEL and the preset needs to be built accordingly.
Gtr Amp Input presets should be used in front of a (real) head or combo. Guitar->Axe-Fx->Amp Input.
Other setups also exist (e.g. combinations of the above).
The Axe-Fx II manual (chapter three) includes more information about setups.
"Cab" search results ignore the settings of this filter.