Home Theater Multiple Subwoofer Set-Up & Calibration Guide



Phase should almost always be set to zero for all subs. It should only be altered if its beneficial which is usually not the case. I did mention this in the article under Advanced Calibration tips.
I noticed my subwoofer and mains are out of phase at 80Hz which is my crossover frequency.
I can get them in phase by inverting the phase or by increasing the distance.
Which is the better solution?
I don't have the tools to measure the effect. Are they necessary or is there an obvious choice here?
I can understand how delay works and how a phase inversion switch can work, but how does the variable phase knob on the subwoofer work? And again, is it better to use it than to adjust delay to get the subwoofer and mains in-phase at the crossover frequency?


Hi, I have 4 infinite baffle subwoofers with 2x18” FI3 subs at 2ohms wired in series to make 4ohms, driven by one channel of a behringer EP4000 amp. So, 2 amps with a signal to each from an onkyo 5009. My subs were positioned in the attic a 1/4 of the way in to the room based on dr flody tools Recommend positioning. I can’t move them now so I have what I have. How would you recommend setting the levels of the manifolds? The two fronts are on one amp and therefore one signal from the onkyo. I had expected to set each one up from the listening position to 72db but am not so sure after reading this. Any advice welcome:)


Old thread but as interesting read I need to calibrate my two subs

Latest posts


  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis