Ghostman
Ambassador of the SuperNatural
In the middle of a discussion about speaker outputs, 1x12 vs 4x12 and I'm having a hard time wrapping my head around this. Given a single amplifier, let's say 10w of output, what is the SPL difference at listening position of using a single 1x12 vs a 4x12 given that the speakers are all the same model, impedance, and sensitivity?
My math: 1x12 speaker at 90db sensitivity at 10watts will be "X" SPL. If you add speakers, each speaker will dissipate less power so the net SPL at the end of the equation is the same as "X." So, a single speaker will receive the full 10w when connected by itself, but once you add another speaker, it will only receive 5w as it shares with the other speaker and thus the output from each speaker would be half, or 3db less, of the full rated 10w power rating. Since you've doubled the cone area, you've increased the net SPL output by 3db which negates the loss in power output, leaving a net 0 change. Doubling the speakers again, you half the power again, losing 3db per speaker but gain 3db with increased cone area, and retain the net 0 gain/loss.
Please point me to a website or whitepaper that shows the calculations because simply saying, "It's 6db louder" is no help understanding.
My math: 1x12 speaker at 90db sensitivity at 10watts will be "X" SPL. If you add speakers, each speaker will dissipate less power so the net SPL at the end of the equation is the same as "X." So, a single speaker will receive the full 10w when connected by itself, but once you add another speaker, it will only receive 5w as it shares with the other speaker and thus the output from each speaker would be half, or 3db less, of the full rated 10w power rating. Since you've doubled the cone area, you've increased the net SPL output by 3db which negates the loss in power output, leaving a net 0 change. Doubling the speakers again, you half the power again, losing 3db per speaker but gain 3db with increased cone area, and retain the net 0 gain/loss.
Please point me to a website or whitepaper that shows the calculations because simply saying, "It's 6db louder" is no help understanding.
