John DeVore talks larger drivers and experimental speaker designs

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DeVore and Eames in my home.

Dateline New York/Vancouver: I was able to connect with Mr. John DeVore, of DeVore Fidelity in Denver this October, and over a lovely cocktail or two, our conversation turned to what he had up his very long sleeves over at his factory, and design studio at the Brooklyn Navy Yards. It seems DeVore is monkeying around with larger (15-inch) drivers among many other things. I asked him if we could put a pin in our conversation until after RMAF as I was intrigued when he mentioned the larger-driver experiments he was conducting.

Here’s an edited version of our back-and-forth via email following the Denver show last month. As always, a big ‘thank-you‘ to DeVore for opening up, and sharing his thoughts, and processes with our readers.

RA: Sales have been good of your flagship designs, in particular the O/96 and Gibbon X, but after our conversations at Rocky Mountain in Denver, you made it apparent you’re not content to sit back, even though it’s only been a year since you a debuted the long-awaited production version of the X. You mentioned “bigger drivers, bigger cabinets” in Denver, can you elaborate?

John DeVore and Gibbon X
John DeVore and his latest creation – an almost four-year project – the Gibbon X loudspeaker at RMAF 2015.

JD: “The principal answer is suggested right in your question: “long-awaited production version.” It took a good five years to get the Gibbon X project to a point where I thought it was ready to go on sale. The O/96s took years to complete as well. I work very hard to keep the end products as simple as possible, but not simpler (to hack a famous quote). The irony is that this endeavor is very complicated and time-consuming. The concept of simplicity demands that the essential components are as close to perfect as possible so that the final system functions as intended without requiring complex corrections. Actually that phrase “as close to perfect as possible” is even a bit misleading because of how interdependent all the different pieces of a finished speaker are. I’m not striving for the perfect woofer sitting on a test-bench, or the perfect baffle material for all future cabinets. Drivers, crossover components and circuits, cabinet materials and dimensions, system tuning and damping; all these things effect one another to such an extent that no single component of a speaker design can be finished until nearly all of them are. It’s undoubtedly the slowest way to design a product, but it’s the only way I know to get the result I’m looking for.

“The other reason there’s no laurel resting going on here is there are always multiple projects in the works, generally with the idea of testing the viability of a concept. These could be ideas for future products that need shaking out, or pure clean-slate experiments. I do have some experiments running with larger drivers, again, to get a feel for what we might be able to come up with down the line. I’m always playing with material and dimensional variations of our existing products, because our production models are perfect benchmarks for me to compare against.”

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Ongoing tweeter horn-loading designs.

RA: Designing a new speaker design from scratch, or re-assessing an existing design after some time for a refresh, or update are not – I imagine – an endeavor to take lightly, or that is a “quick fix” by any stretch of the imagination. Tinkering with an existing, beloved, and well-selling design must be a daunting proposition, and some could question the merits of messing with something that many consider perfection (the O/96 and Gibbon X come to mind), so what drives you to push further?

JD: “The only time I ever made an update to an existing product was when I released the “i” version of the Silverback Reference about four years ago. It was a unique situation because the Silverbacks had been for sale nearly a decade at that point, but still represented our flagship speaker. The design of the Gibbon Xs had gotten to a point where it was clear they were going to surpass the Silverbacks in many ways, so I took a look at what could be adapted from the Xs to benefit the older design. Since the two models shared an overall “circuit,” (three-way, sealed midrange, dual opposing woofers, etc.) it turned out that much of the new work could be used to update and refresh the older model.

“The rest of the time I try to let a finished model stand as is, without fiddling around with “A” or “MK II” versions. For example the Gibbon Super 8 didn’t replace the original Gibbon 8, they both stayed in production together. The new Gibbon 88 isn’t necessarily better than the old Super 8, it’s just more inline with our current thinking, incorporating solid bamboo cabinets, increased sensitivity, etc.”

magnets
New mid/bass driver designs with huge magnets, voice coils, and cast baskets.

RA: Overall you seem to prefer to higher-efficiency transducers for your speaker designs, even the three-way Gibbon X comes in at 91.5 dB. Are you a single-ended triode kind of guy, or is there a soft spot for solid state in your audiophile heart? Or does it even matter to you if the musicality is there?

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A man who is sensitive to an amplifier’s needs. Photo courtesy DeVore Fidelity.

JD: “Absolutely. Sensitivity should be as high as possible, but not higher ( :^). This is not simply for single-ended triode amps – higher sensitivity will benefit any system. A 3dB decrease in speaker sensitivity means double the amount of power from your amplifier is wasted as heat. The “not higher” bit simply means I will work very hard to make a driver efficient, but not at the expense of other parameters such as linearity, frequency extension, etc.

“As far as the tubes vs solid-state thing goes, I have roughly an equal amount of each here at the factory. Over the years at HiFi shows I’ve tried to be even-handed with the electronics I’ve used as well. Because my speaker designs have always had very even impedance curves and relatively high sensitivity ratings, many of our customers use tube amps with them. But in my opinion many of the same elements that make a speaker “tube friendly” make it universally amp friendly.”

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Experimenting with phase-plug material.

RA: I know designing or updating a speaker design is an intensely time-consuming affair, and involves dozens of iterations on average just to get the basic speaker premise down, never mind the individual drivers, cabinet construction, and crossover implementation… in all your work over the years on loudspeaker design, and construction is there one speaker in particular that stands out as your personal ‘Holy Grail?’ A design, that when you finished you felt you had perhaps reached an enlightened state of being through the speakers’ ability to communicate the hidden god that lies in the most sublime production of music reproduction?

JD: “Generally the speaker that I’m currently working on, or have most recently completed is the one I’m most engaged with overall. By the time a design is ready for production I’ve spent many thousands of hours with it, even fallen in love with it in a sense.

“That said, elusive as they can be, those moments of real transcendence have come with all of my designs at some point. I can’t consider a speaker project a success unless it has this ability to deeply move me. Not every system can get there, and not all of my speakers can do this in every room, but my goal is to make it possible with reasonable effort to set-up a system with a pair of DeVore Fidelity speakers in it that will transport the listener completely.”

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DeVore O/93 mid/bass driver.









About Rafe Arnott 389 Articles
Editor of InnerFidelity and AudioStream