Frequency Response?

a ported design may have a steeper rolloff than a sealed enclosure which may have less apparent bass but a more gradual slope.

Your room will amplify bass frequency that corresponds to distance between front and back wall. If this distance is 18' then room will amplify 1150/18'/2=32Hz (where 1150 is speed of sound in ft/s and 2 is for travel forth and back to add).

I read somewhere where you are not gonna get anything below 40Hz in a live performance, except maybe a movie.

"I read somewhere where you are not gonna get anything below 40Hz in a live performance, except maybe a movie."

Possibly, if all piano performances don't use the lower 7 keys (27.5 - 38.9 Hz), and all the string basses don't use the 5th string (30.9 Hz), etc, etc.

Lowest bass string E=41.2Hz With 5 or 6 string basses lowest frequency is still 41.2Hz because it is only for the ease of playing (music is typically written for 4 string bass). The issue here is not only extension but quality of the bass. My new Hyperions HPS-938 don't have extension of previous speakers but have better bass - more natural string attack and decay, better dynamics, less resonances etc. Tuning of the port, in addition to better woofers, plays role. With popular mass market speakers bass extension is what sells the speaker, no matter how distorted or poorly defined it is.

Yes piano goes lower, some special pianos even down to 16Hz but I don't know how often lowest A=27.5Hz is played. Perhaps not very often but in either case I can live without it.