Idea is difficult for me to understand.
say 1×12 speaker that is 500watts
or 2 2x12's @ 110watts each totalling a 220watts
which one is loudest, and why exactly.
Wattage alone will only tell you how loud a speaker will get before it blows up and without the efficiency spec you can't even figure that out.
For the sake of comparison, we will just assume that both speakers are rated at 100db efficiency (@1khz). Given that it takes a doubling of power to get a 3db increase in volume, the 1x12 speaker rated at 500w will do the following:
1w = 100db
2w = 103db
4w = 106db
8w = 109db
16w = 112db
32w = 115db
64w = 118db
128w = 121db
256w = 124db
512w = 127db
It's a little different for the 2x12 because adding in the second speaker adds 3db (for the same amount of power) and as you noted the wattage doubles. So that goes like this:
1w = 103db
2w = 106db
4w = 109db
8w = 112db
16w = 115db
32w = 118db
64w = 121db
128w = 124db
256w = 127db
So, if the speakers in question were of the same efficiency and only the wattage is different then they will get roughly the same amount of loud before blowing up.
Of course, everything changes when you change efficiency... what if the speaker in the 1x12 was rated at 85db (@1khz)... then that would go like this:
1w = 85db
2w = 88db
4w = 91db
8w = 94db
16w = 97db
32w = 100db
64w = 103db
128w = 106db
256w = 109db
512w = 112db
All of this changes again if you factor in the amps power ratings.... worst possible case... a low efficiency speaker with an amp whose spec is based off of 2ohm rating... If an amp is rated at 100w at 2ohms, it's closer to 50w at 4ohms and 25w at 8ohms.... roughly... If you pair that with an 85db (@1khz) speaker and you have the following:
1w = 85db
2w = 88db
4w = 91db
8w = 94db
16w = 97db
32w = 100db
As you can tell there are many factors that help to determine how loud something can get and even what I've detailed above doesn't cover everything.
Hopefully this helps! You are asking good questions.. keep them coming, it's the best way to learn!
Thanks,
Mick
