Stupid filter question

[Rockhorst]

So look at this picture



I totally get how both can work as a high pass filter: for high frequencies the capacitor is basically a short and for low frequencies it's an open circuit. About the opposite for low frequencies. In the bottom circuit, the pot impedes high frequencies to escaping through the capacitor.

For the top circuit the cut off frequency is calculated by RC, the product of the resistance and the capacitance. Is that the same for the bottom circuit?