The speakers I'm about to recommend are not floorstanders but meet your criteria to a tee. If you don't mind, may I recommend the Clearwave Duet 6 monitors?
In my small to medium sized room they go clean (+/-2db) from 1Khz down to 40Hz, down about 4-5db @31.5Hz and have measurable output @20Hz about 1 meter from the driver. If you listen at mid 70s spl you'll get convincing enough bass to forgo a sub.
I have a review under the speaker review section if you're interested.
All the best,
Nonoise
In my small to medium sized room they go clean (+/-2db) from 1Khz down to 40Hz, down about 4-5db @31.5Hz and have measurable output @20Hz about 1 meter from the driver. If you listen at mid 70s spl you'll get convincing enough bass to forgo a sub.
I have a review under the speaker review section if you're interested.
All the best,
Nonoise