How do I calibrated 3 15 " thx monoliths with audyssey from a marantz avr .avr has 2 sub in . Two subs are ran directly to the avr . To add the 3rd I m gonna use the y adapter to run to one of the ither subs. But then how would I go about Recalibrate it with audyssey !? I ve done it with two , but have no idea how it's gonna work adding another to the mix .