I have one sub out of the Ref 30 that I have Y'd to a Servo 15 and a Von Schweikert S/3. There is only one line in on the Servo but on the S/3 there is a Right channel line in and out and a left line in and out. If I remember you are supposed to connect a Y from the sub to the cable coming from the Ref 30 sub out to get a small increase in decibles.Do I connect the Y to the left and right line in on the sub to get this increase? Thanks its been awhile. Steve M.