I started designing stereo equipment when I was 13. At 17 I started selling my speakers at a local dealer alongside brands like Denon, KEF, B&W and PS Audio. After getting my degree, I spent three years at Jensen designing car speakers for the Honda Civic, Acura Vigor, Ford Probe, Jeep Cherokee and Chrysler Cirrus. I worked on a servo subwoofer (reducing distortion with accelerometer and feedback loop) that never saw the light of day. Since then audio has been a hobby – and a pretty serious one.
When I was 13, an ad for Speaker Builder Magazine (now AudioXpress) said, “The speaker you really want may only be possible if you build it yourself. That’s because you’re not restrained by the inevitable compromises of a commercial design.” That is indeed true. Today, many serious hobbyists all over the world have built my designs. I showcase some of those designs on this page.
For example my “Live Edge Dipoles” are pictured left and made the cover of January 2021’s AudioXpress magazine.
I upgraded the design, and in 2023 the Live Edge Dipoles won First Place at the International Speaker Design Competition. Details on the new design here.
The Aegean Wave Dipoles (Pictured lower right)– Open Baffle design using a Tang Band bending wave driver.
The Beryllium Live Edge Cottonwood Dipoles (Pictured below)
The Bitches Brew Open Baffle Live Edge Speakers made from book matched Spalted Sycamore. Refer to the DiyAudio discussion forum for details and open Q&A with hobbyists who are building this system. Jakob Pettersson who built his own version of these said, “The best speaker I have ever heard. I had a friend over and he said the same thing. I was at a hifishop and listened to the Avantgarde trio system that retails at approx $300k usd here in Sweden but both him and I think this sounds better.”
John Hilgers in Wisconsin wrote me the day he got his Bitches Brews working: "I play clarinet. My wife upstairs thought I was practicing when I was playing a clarinet recording. She’s never made that mistake before."
My article “The DSP Assisted Reflex” in AudioXpress Magazine – shows how you can squeeze an extra octave of bass or 6-12 dB additional output out of a ported design, using Digital Signal Processing.
My 1990 derivation of the Mathematics of the Transmission Line speaker enclosure, for my acoustics class in Electrical Engineering school.
My interview about the Bitches Brew design at the Parts Express international speaker design competition:
I invented a new kind of speaker enclosure in 2021: A Reflex+Open Baffle Hybrid with a single woofer. Details and photos here.
The Walnut Dipoles – Open Baffle 2-way with passive crossovers with a unique “Marshall Bass Boost Circuit” that adds +5dB at 45Hz. I can’t be the first person to have ever discovered this circuit, but it’s the first time I’ve ever seen it written up and properly explained. “Open Baffle Bass Boost: +4 to +7dB w/ Passive Xover, No DSP”
The Ultimate 2-Way System – Bohlender-Graebner Ribbons
The Faital Italian Dipoles – Open Baffle design based on a Faital’s 12″ Coaxial driver
The Crimson Bass Monsters (Transmission Lines) using Morel and SB Acoustics drivers. (In 1990 I wrote a paper for an acoustics class, deriving the math for the Transmission Line speaker model. It is posted online here.)
©Copyright 2023 Perry S. Marshall
805 Lake Street #295, Oak Park, IL 60301