AES Section Meeting Reports

Pacific Northwest - February 26, 2020

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The PNW Section welcomed Gary Gesellchen of Vanatoo LLC for its February meeting on loudspeaker design. Vanatoo has carved out a place in the small, high-end powered speaker market. Gary, with his business partner Rick Kernen, previously presented to the PNW Section in 2013, with their experiences creating an audio company. About 37 people attended (17 were AES members) the meeting at the Digipen Institute of Technology in Redmond WA.

Gary Gesellchen is a Mechanical Engineer who built his first pair of custom speakers while still in high school. He launched his own speaker company, Vanatoo, with Rick Kernen after a 25 year career in design, manufacturing, and management with electromechanical computer peripherals makers (disk drives and printers). His presentation this evening focused on the bass reflex design process. He explained the bass reflex characteristics, and showed how one might take all the desired parameters to arrive at a viable design. In the end, a passive radiator can be a better choice than a port.

Building on the well-known work of Thiele and Small, which standardized the mathematical model of speaker design, Gesellchen uses some modeling methods that make it easier to run on ordinary spreadsheet programs. He reiterated that the models are for small signal and not so good for large excursions. He also likes the 4th order Butterworth high-pass alignment for a variety of reasons. When the maximum SPL and desired low frequency response is identified, the port and driver size can be found. Further modeling with box size and power requirements allows homing in on a design. He cited vintage work on power requirements from Josef Hofmann of KLH, whose "Iron Law" predicted speaker power requirements. Vanatoo's current flagship product went with a passive radiator to get the box size down.

Gary provided all of his design process in a White Paper, as well as Excel spreadsheets for all to try. The PNW Section website will provide full details:

After the presentation, some light refreshments were consumed, and door prizes were awarded to:
USB Drive - Rob Baum
Neutrik pen - Jayney Wallick
Fluke Mini-Maglite incandescent (courtesy Rick Rodriguez) - Rick Chinn
Fluke hat-light (courtesy Rick Rodriguez) - Matt Stearns

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AES - Audio Engineering Society