Regarding Sunfire (Cinema Grand) vs RF-83, I learned the hard way that these amps must be properly ventilated or they can overheat and fail. When I inadvertently left the amplifier on in a closed cabinet overnight, with no signal, it got hot. Then, when I put a signal through it, I heard some very disturbing sounds emanating from the left RF-83. Shortly thereafter, billows of acrid grey smoke spewed from the rear vents at the bottom of the speaker (a lot).
The horn and all three woofers had been fried. The woofer voice coils had melted to slag, so the cones were frozen solid n their baffles. Apparently, an outpu transistor for the left side went on the fritz. Of note, the Klipsch crossover appears unscathed.
Lowry