Bohlender-Graebener ... Manufacturer of the Radia and Acculine speaker lines.
The Subwoofer DIY Page v1.1 ...Brian Steele hosts The Subwoofer DIY Page, and is an active member of the Bass/DIY List on the Internet.
DECCA London Ribbon horn tweeter or super tweeter ...Courtesy of the Audio & Music Bulletin website.
Magnet Sales & Manufacturing, Inc. Design Page ...Extensive online magnetic design tutorial materials.
Acoustic Line Source Research - Table of Contents.