I sure would think it is a MSW. But I was amazed that it did not add noise to a sound amplifier, but in fact filtered out the normal hum it always had. Besides, that, that speaker has a 300 watt max input wattage. But it didn't give even a hint of distortion even on the loudest peaks. And the batt voltage held 12.4 down to 12.2 on a 30 minute gig. I'm still amazed at its performance.
Longivity ??? But it does not seem to run hot at all, and like I said, perfectly quiet.
Oh yeah, forgot to say this, it has a cig liter plug. so the first thing I do is chop the plug off. But somehow (easier when ya get old)
I crossed the polarity, and it was lites out. So hoping for the best, I pull the back off, and there sits a smoked 30 amp fuse,.....replace it, and it works like a new'rn. That's when I could not see any fan inside.