Presentation to the San Francisco Section of the AES, February 18, 1989

LOUDSPEAKERS

Brian J. Elliott
- Fletcher-Munson revisited
- Acousto-mechanical diodes
- Power advantage in active speaker systems
- Dipoles for the two bottom octaves
- Audibility of harmonic distortion at very low frequencies

Floyd E. Toole
- Subjective evaluation of loudspeaker systems
- Speaker/room interaction

Siegfried Linkwitz
- A loudspeaker with broadband directivity for reduced room interaction

3-way dipole with sealed box single sub

Magnet mounted woofers and rear tweeter. Upper mid and tweeter baffle experiment.

Rejection of side-wall and rear-wall reflections at the listening position by speaker toe-in

Estimated volume displacement requirements for dipole woofers at low frequencies

At the time of the talk I was still using a single, closed box, equalized woofer with two 12" drivers, figuring that it would take a total of ten 12" drivers in open baffle configuration to replace this woofer. I could not make room for that, though I had been extremely impressed by Brian Elliotts' six drivers per side dipole woofer columns, which rendered the most real bass reproduction I had ever heard. Later I learned from Donald Barringer, recording engineer for the U.S. Marine Band, that even two drivers per side could provide quite natural bass. Thus, I followed their lead and changed to dipole bass for more realistic reproduction of acoustic instruments.