What is the effect of one sub not working in a three sub(shared volume)ported system? Does the not working sub decrease output by moving in the opposite direction of the other two? I'm still getting lots of output(not nearly as much as before though) and it sounds muddy( assume it's due to the volume being more than designed for and tuning is off the mark. Opinions please and thank you.

Would the 3rd sub act sort of like a passive radiator making it kind of like a ported box? It probably wouldnt sound that great though because I dont imagine it would be tuned correctly if that would be the case.

I could be totally wrong on this, just taking a stab at it.

o.k found the problem, one of the voice coil leads was cold soldered and slightly corroded. A little soldering iron and I'm back in business.