Ive tried finding this online and cant seem to find it. Why are my old Cerwin Vega DX3's so efficient at 94db, yet my mid range Infinity Beta 50's are 91db and my girlfriends B&W 804 Nautilus' are only 87 or 89db. Whats the point of having a speaker that takes a beast of an amp to drive vs a speaker thats easy to drive? One would think the Cerwin Vegas would be the least efficent speakers while the B&W's the most efficient. But thats not the case.