Hi all,
Yes, it's a tricky concept to get your head around. As pmbuko has pointed out, it's the "crack" of a mallet against the drum head that is in the midrange, and that is reproduced by your front left and right speakers. The subsequent slow reverberations of the drum's diaphragm at 30 Hz or 25 Hz or 40 Hz are what add the heft--those are omnidirectional and your brain integrates the two and makes it seem as if the big drum is placed somewhere at the front of the soundstage.
In my setup, the EP500 is against the rear wall at one end of the couch, yet the big orchestral bass drum sound on a recording is nicely placed at the back of the orchestra up front.
With movie soundtrack explosions off-screen, the initial percussive part of the explosion is placed by one of your surround speakers at the side or back, then the deep bass energy of the explosion is reproduced by the subwoofer. Your brain "hears" the explosion at the side/rear, even if the subwoofer happens to be at the front (all this assumes correct setting of the sub crossover to 80 Hz or lower.)
Regards,
Alan
