Monoprice has the Monolith by Monoprice THX-365T THX Ultra Certified Dolby Atmos Enabled Mini-Tower Speaker for $255.49. Change quantity to 2 to reach $511 - $25 off with coupon code SAVE25 in cart = $486 with free shipping.

Has two 6.5" woofers, 2" silk dome midrange driver, 1" tweeter, dual binding posts and HDF speaker cabinet.