how to double my SPL or increase it

[TenPennyTowers]

i just got 2, 18" Alto Powered Subwoofers each powered by a 1200 watt class D amp..

my question is how do i increase my SPL.

each is 123SPL continuous , and 126SPL peak.

if i stack one sub on top of the other how much SPL will i gain?
will it hit me in the chest harder or just sound better or smoother?
im new to all this so if i sound dumb its because i am haha..

 

[Nestor]

Stacking your Altos will only give you a gain in floor space.

With two subs, you can, however, experiment with placement to deal with room nodes.

 

[markw]

What are you asking here?

If you double the SPL, you would either get another speaker or, assuming it can handle it, double the power to that one speaker.

That would result in an audible increase of about three decibels, which is barely audible.

Now, if you mean doubling the apparent loudness, that would require about ten additional speakers and the additional power amps to drive each of them or, if your speaker can handle it, about ten times the power to that one speaker.

Here's a couple of links to help explain what I think you're asking

With this one, what I just said above is illustrate in the fourth chart down.

If you want a little more meat on them thar bare bones, this link should flesh them out a bit more.

 

[mtrycrafts]

i just got 2, 18" Alto Powered Subwoofers each powered by a 1200 watt class D amp..

my question is how do i increase my SPL.

each is 123SPL continuous , and 126SPL peak.

if i stack one sub on top of the other how much SPL will i gain?
will it hit me in the chest harder or just sound better or smoother?
im new to all this so if i sound dumb its because i am haha..

Not sure what you are really after here. Is one sub not enough? Or two? You want windows rattling or breaking? Do you wear ear protection at those levels?

Do you have the right source that contains signal levels above 115 dB spl?

If you double the driver area and double the power as you are doing each having its own power, you would get a 6 dB spl gain if the two are in the same location, stacked.