Losing Your Breath With Bronze

Kim Phelan

Artist, entrepreneur, audiophile, and lover of American manufacturing processes, John DeVore experienced green sand casting the way he experiences other discoveries and creative channels in his occupation––with admiration, fascination and joy. This too is his wish for how customers will consume music from his masterpiece hi-fi sound system, parts of which he had the “audacity” to reimagine as bronze castings. More than that, he would have them sit down with friends in the most special place of the house and utterly lose their breath as Ella Fitzgerald enters the room. 

This is the story of how DeVore, founder of 20-year-old DeVore Fidelity in Brooklyn, realized his 10-year-long vision for creating the ultimate, no-limits, most exquisite speakers he believes one can make or money buy.
He did so with the collaborative support of manufacturing design expert Christopher Hildebrand, founder of Tektonics Design Group in Richmond, Virginia, as well as the casting professionals at AFS Corporate Member Ball Brass & Aluminum Foundry (Auburn, Indiana), to whom DeVore refers as a “badass” and “beautiful example” of American manufacturing totally unknown to the audio industry. 

DeVore supplied direction as well as gallery-worthy illustrations to Hildebrand (also founder of his own hi-fi company, Fern & Roby), who interceded as consultative project manager and provided parts finishing; and Ball Brass performed the casting production. The outcome from his suppliers so thrilled DeVore, he created a YouTube video as a tribute to the process and the players. 

It turns out, perhaps the most pivotal element that separates his new “O/Reference 96” model (O for Orangutan) from previous O series units, as well as all previous members of his “Gibbon” family of speakers, is indeed the bronze casting of woofer baskets, tweeter horns, mounting flanges, and a few other parts. Bronze not only bestowed a warm, pleasing aesthetic but, according to DeVore, somehow elevated the rich sound quality of his speakers to an astounding new height.

His first Ball Brass casting run, managed by Hildebrand, comprised 100 baskets, and today another 100 are in progress.
DeVore Fidelity, a skilled band of five whose tiny factory resides in the manufacturing hub at the former Brooklyn Navy Yard, has been fêted near and far by the audio technology trade press. Each system produced is hand-assembled and, working with one of the world’s leading driver manufacturers, SEAS in Norway, the company has quickly built for itself international respect and repute. But building his top-of-the-line O/Ref 96 that retails for almost $100,000 was a new kind of labor of love for DeVore. He knows he won’t recoup the expense of creating this luxe of listening through its sales alone, but he gave himself permission to create without boundaries, reasoning that his new design developments would be repurposed in upcoming mid-range units, and thus nothing wasted.  

Built into a cabinet on legs with classic midcentury vibe, O/Ref 96 was designed as much for visual effect as audio excellence—and DeVore intends for his customer to incorporate it as a thing of beauty in the living room, not squirreled out of sight. And so, it is to the living room we figuratively withdraw, to sit with John DeVore and Christopher Hildebrand as they pull back a small curtain’s corner into their well-choreographed casting and machining triumph.  

A CASTING SOURCE Q&A

Casting Source: Speaker parts from driver manufacturers are typically an “off-the-shelf” kind of commodity cast in zinc—why did you want to customize your own 
in bronze?

DeVore: I went to art school, so my interest in bronze parts for the speakers significantly predates my knowing Christopher ... but I learned about Christopher from some of his early hi-fi products a few years ago, including some turntables that had cast bronze platters, and his top-of-the-line turntable actually has a sand cast, pebbly iron base. I saw that, and I had already been interested in doing bronze parts. 
I approached my driver manufacturer, but they’re set up for mass producing in Zamac (zinc, aluminum, magnesium, and copper alloy) and aluminum ... I knew it wasn’t going to happen that way. In the meantime, my normal line was selling really well. My design process is very slow, so it wasn’t until maybe three years ago now that I was ready to kind of reassess this idea of getting bronze. 
Prototypes from a foundry in Pennsylvania were my proof of concept that bronze was better sounding; the material behaved better––structurally it was sounder––and aesthetically it was beautiful. We built them and listened to them, and the end results were even better than I was hoping ... The bronze is integral to the sound, but it’s also integral to the really beautiful, hand-built in the U.S. pride of ownership for end users.

Casting Source: Why did you select Ball Brass for the job?

Hildebrand: I was really interested in somebody that has a lot of experience and modern molding equipment. They have a Sinto molder—that’s important, because it allows high volume, but it also means there’s great repeatability in it. If you’re trying to do a complex casting like John’s basket, which is a spread-out armature––a cage––it’s really important that you have great molding and consistency happening; otherwise, you’ll have an outrageous reject rate.

Their molding in general is really world class––they have a great facility and they’ve had a lot of people working there with a lot of experience ... I needed to feel comfortable with somebody who could support us, because when I’m acting as the “general contractor” in the casting part of the process, I own the success but also any failure that can happen there.
We consulted with them on things like, how do we want to lay out where the patterns are on the match plate, and where do you guys want to mount your gating. 

DeVore: I’ll add that we needed these particular alloys, so we needed somebody who could do that, and we needed somebody who could do a smaller quantity—our first run was only 100 of these baskets. We needed it to be beautiful out of the mold because we knew we wouldn’t be machining that [basket] part; we’d only be machining the parts that needed to have a real surface for glue or a surface perfectly to spec for mounting on with screws and everything. Those kinds of areas would be machined, but the rest had to be beautiful on their own.

Casting Source: What was the full range of parts Ball Brass cast for DeVore Fidelity?

Hildebrand: After we successfully produced the baskets, John asked me to look at the horns for the tweeters ... there’s a tweeter and a super tweeter on the Reference speakers; they’re also called waveguides and they control how the wave propagates and breaks off around the speaker itself. They’re the “pucks” he talks about in his video. 

There’s a couple other parts we made castings for, including the ports, which needed to be produced in the same alloy; they required a continuous cast process (from another vendor) to get the wall thickness required for the design. 

There are also some user interface plates on the bottom of the Reference and subwoofer. Originally, we had purchased plate material and machined from that, but when we got to the point where we were using this bronze alloy, I told John we should go ahead and make patterns for those, too—so that meant we had a consistency of the alloy throughout and really good use of material for all the parts.

Casting Source: What are the attributes of the system that stand out most to you?

DeVore:  The finish. The finish that faces the customer is a beautiful, machined sort of fine brushed texture, and it just catches the light. The curve of the bronze around the tweeter is dazzling. Then that visible ring around the woofer just dances as the light hits it. 

That was a big part of it—you know, you’re asking a customer to spend a lot of money, so they have every right to expect gobs and gobs of pride of ownership. You want them to bring a friend into their listening room, and you want their friend to just lose their breath. 

You can make beautiful texture on aluminum or zinc, but it doesn’t compare to the depth of color that you get with bronze. And you know, we have the ability to do a clear coat if people want that. But I made sure that it oxidized a little bit over time before we brought it to a show because then you get that deeper sort of amber gold color. And all of that contributes to making the speakers worth that money. 

Casting Source: Were there any particularly vexing challenges along the way? 

Hildebrand: With any process that involves a lot of people in production, there’s the very obvious things you have to pay attention to: how do you get it to cast well. And then there’s the care in decanting it from the mold, or looking at possible problems with cold shuts, inclusions, and other processes on the foundry side of things. Ball Brass has been a really great company to work with, refining and managing those steps. 
But because of all the variables, I drove out to Indiana for the first run to basically be present and articulate what was important. Otherwise, we could be shipping 100 castings to Virginia and rejecting a whole bunch. So, they were very gracious to put up with me being in their space while they were doing it the first time. 

And you know what, they had like 10 of them ready for me to inspect when I arrived. I showed them what was acceptable and then they ran 100 for me. Then, we loaded them up the next day, and I drove them back so we could meet John’s show deadline.

Another big part of the challenge of our job—and what informed our approach to helping design the casting and the tooling—was, how are we going to machine it? How do we hold onto it? Thinking through the tooling and the process of how to have the fixturing to hold the part while you machine it—that’s actually the heart in machining. 

Programming it and knowing what tools to select for what materials ...  that’s on a spreadsheet. You can find that data. Making the fixturing to hold the part is really where the heart of it is. 

Casting Source: As you look back on the journey, what are you most proud of?

DeVore:  The sonic end result aside—because that was the goal and that was achieved—it’s this incredible glimpse into old school, beautiful American manufacturing that nobody in high-end audio has seen or uses. So that’s been a huge part of my marketing material: Look at what America can still do. 

A lot of the speakers that we compete against are using off-the-shelf parts, and the few that are using completely custom baskets, they get a giant block of aluminum and they just mill out 99% of it and say, “Here’s our custom basket.” 

That costs the same to make one as it costs to make 10, whereas with casting, the more you make, the cheaper they become, because literally all of the cost is upfront. You can never machine a basket and end up with something that says gorgeous like those sand cast bronze parts.

Aside from the elegance of that kind of manufacturing and the beauty of the end result, for me, it’s the way it should be done.

I wanted O/Ref to be a proper representation of what can be done in the U.S., and that is 100% what Ball Brass did. You hold one in your hand, and you just want to rub your thumb against that texture. There’s no way I could have done it any other way.     CS

View the article in the digital edition of July/August Casting Source.