Hi,
The problem was probably that Tuffer had to much heat from the Power Resistors and not any sound at all.
First I said Tuffer could change the PowerResistor from 15 ohm to a 8 ohm (and take out the shunt 15 ohm resistor, he doesn't need it).
Second the bulb comes from the factory with a xover for some Eminence speakers (standard; they don't say which) for 250W of power compression 3:1 and Tuffer is using 400W and more. And when the things get hot and Tuffer doesn't get any sound from it (PSD2002), the bulbs are before the network and explode.Nice, but it needs some changes. My speakers have two light bulbs in series (12V 21W). Wayne, maybe Tuffer can use a 24V 21W Truck light bulb, what do you think?
Tuffer you can check the lamps from OSRAM. They have a nice catalog for 5W and 10W Festoon Lamps.