Phase settings

I have read the phase set up on Rythmik website and understand the importance of this adjustment. Does anyone have a trick to setting this? Just go for the strongest sound? I have a stereo preamp. I have to make all my adjustments on the sub. I am into straight 2 channel music. Preamp, amp here only.
I just received my F12, it blows away my old sub, dont want to say bad things but the F12 is so much better. My next sub will be another F12 or F15. Wife wants to rumble with the movies.:rolleyes:

Here's the way Absolute Sound says to do it:

But there’s a much more precise way of
setting the phase control that guarantees
perfect phase alignment between the sub-
woofer and main speakers. First, reverse the
connections on your main loudspeakers
so that the black speaker wire goes to the
speaker’s red terminal, and the red speaker
wire goes to the speaker’s black terminal.
Do this with both speakers. Now, from a
test CD that includes pure test tones, select
the track whose frequency is the same as
the subwoofer’s crossover frequency. Sit
in the listening position and have a friend
rotate the subwoofer’s phase control until
you hear the least amount of bass. The sub-
woofer’s phase control is now set perfectly.
Return your speaker connections to their
previous (correct) positions: red to red, black
to black.