Thin-wall multi-concentric sleeve speaker

An acoustic transmission line speaker enclosure comprising:

• a speaker driver mounting site defining front and rear directions;
• a first cylinder positioned relative to said speaker mounting site to receive at a first end a rear-traveling sound wave and to emanate at a second end said rear-traveling sound wave;
• a second cylinder concentric to and relatively larger than said first cylinder, an inner radius of said second cylinder being selected relative to an outer radius of said first cylinder to establish a space between said first and second cylinders of cross-sectional area substantially equal to an inner cross-sectional area of said first cylinder, a first end of said second cylinder being adjacent said first end of said first cylinder and a second end of said second cylinder being adjacent said second end of said first cylinder;
• a cap at said second end of said second cylinder directing said rear-traveling sound wave from said first cylinder into said space between said first and second cylinders while maintaining therealong a cross-sectional area substantially equal to that of said space;
• a sleeve surrounding said second cylinder, said sleeve including a first end adjacent said first end of said second cylinder and a second end adjacent said second end of said second cylinder;
• and
• a guide coupling said first end of said first cylinder and said first end of said sleeve and being spaced from the first end of said second cylinder whereby said guide directs said rear-traveling sound wave out of said second cylinder and into a space between said second cylinder and said sleeve, said sleeve including outer walls adapted for vibration in response to sound energy between said sleeve and said second cylinder and thereby coupling sound energy therethrough.