DBs. More power a driver can safely sustain means the more it reproduces into sound waves. Think of it like a light bulb. The more wattage that is consumed the more energy is transformed into the final product. More watts, more light.
More watts into a driver equals more sound output. The suspension, spider, motor, ect, all must be designed to handle the physical motions of producing the sound accurately when given a clean signal.
Just like the filament in a 100w light bulb must be designed to handle the increased consumption over a 60w bulb so must a speaker and its' parts.
Often, while a sub is meant to handle more power it also has a higher sensitivity rating. For instance in 18" size:
Fi SSD has 91.4db sensitivity, with 800rms rating. Fi BTL has 94.9db sensitivity, with 2000 rms rating.
From this statement the BTL should be 3.5db louder with 1 watt of power, though it doesn't always work out that way. In a direct swap out of subs the BTL should be louder at any power range. It's just the way the subs are made- one is more efficient.
but in some cases a lower rms line of subs can outpreform a higher rms line of subs on the same power until there is enough power to really get the higher rms sub really moving...
I apologize ifthat sounds confusing...
The first example that pops into my head is The Audible insanity DD van.. They went with the dd1515 (iirc) over say the dd3515's because the 1515 outperform the 3515's until a certain wattage even though the 3515 has a higher effiency rating... If I got the exact model of their subs incorrect , I apologize.. Maybe Canaan will read this and clarify what I'm trying to say.. (or correct me if I misunderstood). They are the ones who did the testing on em..
The way I understood it, with their available power they are able to get better numbers by not going with the more powerful rated subs... Fu<k, it's late and I'm confusing myself. lol
Is it kinda like a subcompact car and a big truck. with a small engine/HP, the subcompact will outperform but as you increase the power past a certain point the truck will have no competition?