calaverasgrande wrote:Well the one in the link does not give an SPL at 1 meter for 1 watt. That is the standard benckmark which is used to judge sensitivity.
"12" Mineral-filled polymer cone, wide rubber surround, super duty silver coated 1000 watt rated braided tinsel lead wires, deep frame, 3/8" top plate, 3/8" rounded bumped machined back plate, T-shaped steel pole piece, dual poly-cotton spiders, dual terminal 2" voice coils (4 ohms per coil), non-bottoming design. X-max 16 mm"
So it's 4 ohms and allegedly 1000 watts (more likely 500 watts X 2 voice coils) and has an xMax of 16mm.
I dont see a bandwidth or sensitivity measure.
What it boils down to is that there are tradeoffs for every kind of application. You can have sub lows with low sensitivity, or relatively weak lows with high sensitivity. You also have to take into account power handling, or more accurately thermal capacity.
As you go lower in frequency it takes more power to generate sound at the same level. 40 hz takes 100 watts to be as loud as 80 hz at 50 watts. 20 hz will need 200 watts to be as loud. Add this along with how thermal ratings work (an 800 watt woofer FAILS at 800 watts) and the picture starts to get clearer.
There are apparently arcane reasons for this having to do with the surround construction, the former and the voice coil.
What I think it boils down to is this, you can make a nice light driver that has 20-10k bandwidth but it only handles 100 watts.
If you toughen up the speaker to be able to handle 500 watts you no longer have light speaker so you lose the high end. I assume there is a corresponding ding from making the former or surround more robust which affects low frequency.
Most of Kinetic Audio's speakers have an SPL of 91-95. Not sure of the AmpEater II, but the original AmpEater had an SPL of 94dB at 1W/1m. Only handled about 100W, though. I have one that I built from a kit in my Phonic MK-50. The rest of what you say does make sense, as well. Pro speakers have a higher power rating, therefore they put out less VLF. They are heavier in construction to handle more power, and therefore can't move as much air as required for VLF. Thanks! BTW, the AmpEater II has a frequency range of 10-2000Hz, according to www.kineticaudio.com/catalog.htm