One of the drawbacks of having an extremely sensitive speaker system, eg 103db @ 1metre, is that everything, and I mean, EVERYTHING, can be heard- funky ground- big time sound through those horns, tube rush or other noise associated with electronics- welcome to a proctological exam of your system.
Wasn't the original rationale of the sealed box to give big bass in a small enclosure? And, that coincided with the intro of solid state electronics, which had the power to drive them?
I agree with Plato that the interaction between components ultimately means that you could own two absolutely great pieces of gear that really don't mate well.