Smallest room dimensions for good bass to 20hz

This is only anecdotal;I'm not a physicist.

The lowest note a string bass plays is 41hz,which works out to about 29 feet,so the half wave would be about 15 feet.

With the exception of some organ pipes,most reproduction at 20 hz would be difference tones. (A tone at sixty generates a difference tone at thirty,and fifteen,and seven and a half,and so on. This is the ambiance you get in a concert hall,where the reverb is maybe a second. For more,see Carl Seashore's Psychology of Music.)

Keep in mind that the lower the pitch,the less directional it is. A 41hz tone,generating an half wave of fifteen feet,would bounce off a fourteen foot ceiling.

**So my point,and it is only anecdotal,is that deadening the room(including the ceiling) to absorb sound is probably more important than the size of the room.

Is using a headphone the same as listening to speakers in an anechoic chamber?

Chris

"Is using a headphone the same as listening to speakers in an anechoic chamber?"

Similar, but the headphones are more efficient. Try listening to speakers outside sometime. You practically have to 'wear' them (like headphones) to get any volume ;-)