[quote name='Phil Starr' timestamp='1407492515' post='2521041']
Bill is of course absolutely right about this. The interesting thing is about what the implications are for us as bassists. If you want a single speaker to do the job for you then you have to have something engineered for high volume displacement. This usually has a cost in terms of efficiency or a large exotic and expensive magnet system.
The other thing is that doubling the number of drivers gives you 3dB of extra sensitivity. 6dB if your amp can maintain the voltage swing. Go to an 8x10 and you have a potential 12dB of sensitivity or 9dB at the same wattage. Although this comes at the cost of the speakers radiation interfering with each other to make a lumpy bumpy frequency response and radiation pattern.
This extra efficiency means that your system is using much less power. 3db is half the power and 10db a tenth. So instead of 400W into an exotic lightweight you might be using 40W into an 8x10 for the same sound level, and only 5W into each of the eight speakers. If you are using the same amp it is going to run cooler and maintain its output, it is also much less likely to distort because of peaks in your playing. More importantly probably the speakers will run cool, 400W into a tiny coil trapped in a tiny air space inside a magnet does get very hot. Speakers running consistently high powers run very hot and the resistance of the coil rises reducing the speakers output so the sound changes as they warm up.
Of course this is only one variable, there are many other differences to take into consideration but there are distinct advantages in multiple speakers vertically stacked.
[/quote] most interesting post i've read for a long time.