Frequency Response?


If a speaker is rated down to a given frequency response (say 40 hz), wouldn't that suggest that 40 hz is about as low as the given driver is capable of reproducing, not accounting for roll off? When taking roll off into concideration, will the driver continue to attempt to reproduce frequencies infinately below the given 40 hz, or is there a point that it is just incapible so it doesn't? What I am asking is, Will a driver designed and constructed to play down to 40 hz even attempt to reproduce a 20 hz signal? I want answers!
62bakes
AFAIK, yes, the driver will continue to attempt to reproduce lower frequencies. Usually manufacturers measure their speakers with a -3db range. So it sounds as if your speakers are down 3 db at 40 hz. Depending on the slope of the crossover will depend of how much rolloff there will be at 20 hz. A 6 db per octave rolloff should be -9 db at 20 hz. A -12 db crossover design would be -15 at 20 hz, etc.
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.