Does room size affect volume and bass?

IN DEALING WITH ROOM SIZE, ACOUSTICAL PROPERTIES OF THE SPEAKER AND WHETHER THE ROOM IS A SOFT OR HARD ROOM PLAY A CRITICAL PART, NOT JUST THE SIZE OF THE ROOM. HIGH FREQUENCY ROLLOFF AND SOUND ABSORBING ROOMS CAN CREATE HAVIC. CEILING HEIGHTH SUCH AS HIGH VAULTED CEILINGS CAN EAT UP SINE WAVE ENERGY AND LOSE SOME OF THE EFFECTS OF THE AUDIO PROGRAM IN THE SOUND REPRODUCTION. THIS IS ESPECIALLY TRUE IN REFERENCE TO THE PROGRAM MATERIAL YOU USED. A PARAMETRIC EQ AND SOUND ANALYIZER CAN TELL YOU IF YOU ARE MISSING OUT.

Bass frequencies can still be perceived accurately in smaller rooms, whether or not the room supports the full wavelength. Bass waveforms do not have to be a "travelling wave" in order to be accurately reproduced.

Carl is absolutely correct. However, the best 40Hz tone I ever heard (electronically) came from standing 27.86 feet from a big Krell pushing a big speaker in a big room!!

Since we are on the subject, if given a choice, how would you position speakers in a half catheral ceiling room? Highest ceiling height above the listener or the opposite? I have two different opinions from speaker designers. Would a half catheral ceiling be desireable as compare to a 8 ft or 10 ft flat ceiling?

Lets not get too technical.A speaker fed identical signal level will produce the same output, but the room will make a big difference, just as where you position speakers does. A small speaker that sounds thin and bright in a large room can be transformed by moving to a smaller room. Low tech demo: pick up your jam-box and walk around the house, it sounds like your changing the volume as you move closer to walls and into smaller areas. Thats why setting up speakers can be so difficult. As always try it in your room .I have heard speakers that would not play bass-lines in my room, sound fine in larger rooms. Try before you buy.