What are the specs of a full range speaker?

No single transducer can handle a full 20 to 20khz frequenc. In the olden days, acceptable single driver to wideband drivers, typically covers from above 50's to near 16 khz signal, something that specs out like 80-16khz, or 70-15khz, enough to have a crossoverless mid; and no associated phasing problems than typical designs that employ crossover. Some people attest too that these driver units are better off partnered with tubed electronics. System integration? most likely.

A speaker that has strong output at 30hz may not be truly fullrange but is plenty of low bass for most music.

Room lock and room shudder are a couple of terms I like to use...room lock sets in around 30hz (or so) as you feel the bass grip the room, we've all felt it I think...feels good.

Room shudder sets in a bit below room lock and can cause the whole room to literally shudder depending on how strong the output is...mostly movies and some New age music come to mind.

Dave

The Apogee Scintilla does 20Hz to 20Khz. There must be others.