Multiple Small Subs - Geddes Approach

[camplo]

1) You've said the source type does not matter, then why didnt you like ported Summa? You could have ported it very low at 25Hz and got a shallow sloped response to blend with other bass sources.

From my experience asking questions, the port just creates one more complexity in phase. If LF extension is challenging excursion then add more woofers. Don't forget also, fixing Group Delay with DSP, adds more delay to the whole signal.