But they dont seem to have boxes which are 500w
rms in my budget.
Don't confuse rated
power handling with output and that it is usually the output rather than the
power that matters. The
power rating tells you how much
power the
speaker can handle, not how loud it can get. The output is a function of the
power and the
speaker sensitivity, which is basically how loud the
speaker gets for a given
voltage or
power level and usually specified at 1
Watt and 1
meter. So you can get increased output by using a different
speaker with the same sensitivity and greater
power handling or by using one with the same
power rating but greater sensitivity. In theory, a
speaker with a 100W
power rating and 100dB@1W/1m sensitivity would have a maximum output of 120dB@1m, approximately the same maximum output as a
speaker rated at 500W and 93dB@1W/1m or one rated for 1,000W and 90dB@1W/1m.
Can i do one thing. I think what your trying to say is that 2 speakers next to each other will cancel the others due to the sound waves (in my layman parlance). So if i put 2 in the front L+R and then have another set of LR a little way into the audience ? Or maybe even all 4 on front but seperated by about 12 feet space between each
speaker on the left and right respectively.
I'm not sure what you believe this will
gain, but you may not see the benefit you expect.
It sounds like your intent is to have two speakers per side with them both covering the same listeners. That is quite different than two speakers arranged such that each
speaker covers half the listener area with a minimum amount of overlap, which reduces the potential issues with interactions between the speakers since most listeners hear primarily one or the other
speaker and few listeners are covered equally by both speakers. In comparison, if listeners hear the same sound from more than one
speaker then the resulting interactions can be significant.
With two speakers of equal
level reproducing the same signal, covering the same listeners and located several feet apart, what is likely to happen is that some listeners will see up to a 6dB increase in
level while others may see virtually no change, with an average increase of around 3dB. That is assuming the
speaker level remained consistent, but as already noted, in your case two speakers on a single amp
channel would actually make those numbers 4dB and 2dB. However, due to the signals from the two speakers arriving at most listeners at slightly different times, along with any change in overall
level they may also experience an
effect on the
frequency response. That
effect will vary throughout the listener area and cannot be addressed with equalization.
That is the physics, but there is also a perceptual aspect. One
element of that is that a 3dB increase in Sound Pressure
Level is generally considered a readily perceptible difference while the 2dB average increase you could expect would be just noticeable and perhaps not even noticeable to some. However, neither is even close to being perceived as twice as loud, which would require a 10dB increase. On the other
hand, studies have shown that we do 'hear with our eyes' and thus some people may perceive two speakers as being louder whether they actually are or not. This is why I sometimes suggest that if people feel they need the look of two speakers to go ahead with that but just don't connect one of them.
Only you can decide whether the actual and perceived effects would be worth it in your applications, but if you are thinking that two speakers would make it twice as loud, that is not going to happen.