Hi,

Tom, Mark, Ivan and all the other people here (please forgive me if your name wasn't there..) I have a question regarding efficiency here...

If one would build a large stack from

a/ Double 18" vented boxes

The efficiency of one 2x18" vented cabinet is around 95..98 dB

Say 100dB for easier calculation...

b/ Horn loaded subs ( TH 112/115/Vortex or whatever)

The efficiency of one Horn loaded cabinet is say around 106dB

in this particular case for easier calculation.

If you have 2, 4, 8, 16, 32, 64 pcs in a stack, how the efficiency raises in both a/ and b/ cases?

I mean having two boxes instead of just one, You would get 3 dB more efficiency and 3 dB more power handling giving 6dB more max SPL.

But efficiency can not raise up to more than 100% right?

And the number of boxes where the 100% efficiency would be reach is not infinite....

So I guess:

Doubling the number of boxes not always results 6 dB max SPL gain anymore. If you have 64 instead of 32 you may only get 3 dB more SPL and this only becouse of the increased power handling and no efficiency increase...

Sure I know SPL can be increased not just by efficiency and input power, but with more directivity as well... (see BDEAPs)

At some point you neither get more directivity when you already reached the dimensions where the majority of the stack is working under quarter space conditions, however this can be true always just for a part of the stack and not for the speakers on the both ends... So you may get more and more boxes to work with increased directivity and with increased radiating impedance due to the sound (air) pressure generated by the other boxes...

So my question is, If Horn loaded boxes have or have not any advantage in this manner when they are used in big stacks?

SO If I use 64 pcs of 2x18" vented cabinets Do I get less Max SPL than using 64 pcs of Horn loaded Subs if the total input power is the same in both cases?

I mean If I only can reach an efficiency of say 120dB 1W 1m including directivity in both cases, then I get the same max SPL when feeding with the same total power, right?

Clear, that I could reach this efficiency margin with horns easier and with less cabinets. Maybe with just 16 pcs...

But what if I add there some more horns? I gues there should be a border somewhere, above I dont get more efficiency, I just can pump more watts into the speaker...

I am wondering if this all is true or not?

If anyone has to say something about this I would appriciate any explanation!

Thanks,

Tamas