Perhaps it’s your Mitsubishi’s that are "bass shy" which is the usual compromise engineers make when designing high efficiency speaker systems. Klipsch Horns and LaScala’s are a perfect example. To achieve their ultra-high efficiency, they had to compromise bass extension as in the LaScala where the minus 6dB point occurs around 50hz. Where the Klipsch Horn if not for using the side walls of the room as an extension of the horn would not be capable of it’s minus 6dB point at 38Hz.
The Cornwall on the other hand which applies a different strategy, using the same 15-inch woofer in a front ported alignment can reach down to 35Hz along with a few decibel compromise in efficiency.

