CHR-70 BR tuning

[mashaffer]

For my mini console project I have a pair of first generation CHR-70s. Initially I intended to use a sealed enclosure and pick up the bottom with an integral sub. Due to cost and size constraints I have pretty well decided to go with a ported enclosure and just provide a line level sub output for an external sub.

The power amp section is Single Ended Ultra Linear KT-88s (with Schade feedback) so about 8 or 10 watts per channel. To protect the drivers and save on amplifier power I intend to put a passive second order HP filter between the preamp section and the power amp section.

According to the simulations I have done it looks like these drivers should get decent response down to about 40Hz so the plan was to place the HP filter crossover at about that point. Give that the filter response is down about 6dB at the crossover I thought that it might be advantageous to design the enclosure for a slight (say 3dB) resonant bump just above 40Hz to compensate for the early (shallow) part of the filters roll off. This should give me two advantages. A more level frequency response in the last half octave or so before the cut off and the ability to provide the same output at crossover with about half the amount of power required v.s. the original tuning (3dB=1/2 power).

Any thoughts on this approach? Any downside? Would the bump cause more smearing of the bass even though compensated for electronically?