This is a great thread!
I've heard for many moons, that a 'doubling' in volume requires 6dB increase. That's an important distinction though.
Not that I love clouding the waters, but water conducts sound so much better than air. I think this is the cause of most of the confusion behind the SPL and dB debate. Air doesn't conduct sound all that well, and much of the pressure is wasted to molecular friction. I remember being underwater at the pool one summer as a kid, and hearing someone's watch beep...from the other end of an olympic size pool.
I did some time training to be an audioprostologist (hearing aids). When measuring dB's AT THE EAR DRUM, the numbers were pretty linear with the audiometer. Being in an air filled room with an dB meter is a whole other ball of worms. Sound waves get cancelled, sure, but some pile up in corners, especially low frequencies, and can wack us upside the head...more so than what you would calculate.
In the original post, the 2 amp proposition leaves something to be desired. Let's put it into real life situations. You set the level of your rig where it sounds best, but add another rig not to get louder but to sound more full. That's a loudness issue, not a volume thing. You would do so to try to fill more space with the same volume so that it's all 100dB anywhere you stand.
Am I crazy?
Fun thread, rock on!
