I can't get a call back from PRG, so here I am.
The impedance curve of the box is attached*. The driver specs I've picked up from here and there over the years are: Nominal Z = 8, Re = 5.6. FS = 25Hz. Pe = 800W (800 continuous sine I believe). Power compression is I believe 1dB at 56V, 2dB at 80V, 3dB @ 100V. I need to set a high-pass and limiter (Rane RPM88 - attack time is in db/sec).
*4 Ohm power resistor in series with the 4 Ohm box, drive level set at each frequency for 4V across the resistor = 1 Ampere through the box.
The problem with saying "sine wave power", is that it can be very misleading.
At what freq was the sine wave applied? A minimum point of actual impedance or the nominal impedance, or some other other freq?
How was the calculation done? Using the actual impedance at that freq or a voltage at some freq and then using the nomimal rating?
Depending on how you do it, you could come up with different ratings when looking at "calculated watts".
I would start with a HP at the tuning freq (25Hz in this case).
The following is based on a "4 ohm rating".
Depending on the type of limiters available and type of musical style usage etc, you could have a thermal limiter at 28V 3 seconds or so up to a peak limiter at 112V.
56V being the continuous limiter setting. 25Hz 40ms attack time.