My main speakers take a nose dive at around 58hz as designed (test CD used to verify this, Heresy III with titanium mid and tweets, better sounding than IVs with poly mid and no horn throat...I tried 'em, IIIs sounded much better). I have 2 older RELs, both kick in at 58hz and work amazingly well. I don't recommend bouncing a cue ball off the wall as it could be bad if you stepped on it in the dark..
How many subs?
I got my room analysed by an acoustic engineer.
3 subs - 2 with delays.
Maybe I did not have the gain set right for each sub?
The pressure in the room was overwhelming. Opening the door was a relief.
One sub - front left - the one with no delay in the design seemed really good.
But I got hungry for more - so I tried 2 subs.
Does anyone have experience with using a multi-sub setup using delays?