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Positive Feedback ISSUE 16
november/december 2004

An interview with Mark Gilmore of Gilmore Audio
by Dave Clark


What is your history in audio?

I've been an avid electronics DIYer ever since I can remember. Music hooked me at a young age, too. It is one of the very few legal drugs. Music helped point me in the direction of a career in electronics industry. I learned to play the acoustic guitar when I was young. Even since then, I've been trying to reproduce the live sound of my favorite guitar in my home—artificially, but with some success.

What is the history of Gilmore?

A few years back, Harry Blazer came to visit and listened to an early prototype, which evolved into what is now our Model 2 speaker. He believed it held great promise, so a great partnership was born.

What else are you involved in?

I was doing digital design and network engineering for major aerospace companies. Most recently, I was involved with a state-of-the art electronics contract manufacturing company and a well-known high-end amplifier manufacturer. Now I'm concentrating exclusively on my efforts with Gilmore Audio.

How do you think a speaker should sound, or for that matter, not sound? I ask this because your speakers cannot be considered "typical."

Thank you for your astute observations. You're right. My speakers are unlike any others. A good speaker should not have an obvious sound of its own. That must be primary if the goal is to reproduce the live event.

Designing a speaker to conform to a particular type of music makes no sense to me. A good speaker should be able to handle any source you throw at it, and should not be optimized for any particular musical genre. I think of a speaker more like how others think of a well-designed, "accurate" amplifier. It should simply pass on the source without change. A speaker needs to do an electrical-to-mechanical translation, so its job is infinitely more difficult. This is where creativity and state-of-the-art materials come into play.

Where do you start? Is it all one happy balancing act or more an issue of tradeoffs?

I don't consider myself a speaker designer. I've studied the popular speaker design texts and found them useful only as a reference. In my mind, the classic speaker design methodology stifles creativity and dooms us to repeating the unsatisfactory results of the past, with only slight sonic advancement. This approach will not get us closer to reproducing the live event any time soon. 

When I devised the concept for my speakers, I borrowed heavily from the efforts of companies like Apogee, Carver, even Sound Labs to some extent. Their products always brought me closer to the live musical event than most others. I've always believed that line source dipoles provide a presentation that is much more like what I hear in a live performance.

I believe that the best way to design a speaker is to go back to the basics. Physics allows us to visualize the perfect loudspeaker, which of course can't exist due to the limitations of physics. Physics is our best friend and also our worst enemy. If we try to visualize the perfect loudspeaker, we have some of the following characteristics:

  • No mass

  • No resonances

  • Perfect 360 degree dispersion

  • Infinite dynamic range

  • Flat frequency response from DC to light

  • 100% efficient

  • No room interaction

  • No distortion products

  • Purely resistive load

The trick is to find creative ways to approach each of these design ideals, within the limits of real-world physics and our available technology. A simple goal, right?

Do you consider price or have more of a "What can I reasonably sell this thing for" approach?

The truth is, I don't think about a price point very much. I've tried my best to create an all-out assault on the state of the art in a given speaker model. I don't give much thought to the design or production compromises that might be consistent with a price point, or what might be considered a "reasonable price point." These things don't mean much when the goal is to produce a product that reflects the best I can do. Once the design is done, the bill of materials is examined and then reality hits hard. A price is chosen to remain profitable, and I can only hope that the results are affordable. High-end loudspeakers are not meant to be affordable. This goes with the territory when you're trying to make a state-of-the-art product.

How does a product come about? Can you trace its beginnings from the twinkle in your eye to a product ready to be sold?

The "twinkle" came about twelve years ago, when I started getting very serious about selecting a speaker that could get me as close as possible to the live musical event in my living room. I was looking for a speaker that I could live with. It was all about compromises, especially back then. I quickly learned that my goal would never be realized. Although there were some relatively fine speakers being sold twelve years ago, they all had serious performance compromises. This is why I was attracted to the Apogee, Carver, and Sound Labs offerings of the time. Although these speakers had a long way to go, they seemed to have the fewest compromises. Each held great promise, and could bring me closer to my music, but would not allow me to realize my sonic goals.

I had no intension of building my own speakers, but since I couldn't find anything that floated my sonic boat, I started modifying Apogee and Carver speakers. I tried to optimize these speakers based on the limitations of physics that we discussed earlier. This taught me a great deal and sent me on my way.

Can you tell me more about your speakers—drivers, crossovers, etc.?

We hand build all of our drivers. I've not yet found any off-the-shelf sources that can provide what we need. Also, I've not yet found a source that can build drivers to our specifications. Our ribbon is purely resistive in the audio spectrum. Its mass is much lower than that of any other planar-magnetic driver out there. Its dynamic range is well past any other as well. It uses a proprietary conductor that is far stronger than what is used in other planar-magnetics. Our woofers exhibit distortion levels at least 10 dB lower than competing drivers. Our ribbon and woofer compression points are extremely high, which yields very low distortion at real-world listening levels.

I tried my best to use wood, or some composite/wood materials, to reduce cost and weight. I was never successful because in-band resonances were always an issue. Once I gave up and went with Corian, the resonance issue was a thing of the past, albeit at a much higher cost. As is usually the case, the level of performance I craved did not come without higher cost.

Our crossover was ultimately installed in a box separate from the speaker panels because I couldn't find a practical method to stop resonances within the crossover enclosure when it was panel mounted. Our crossover is a two-way, fourth-order Linkwitz-Reiley design. It uses only the best components and also very low DC resistance air-core inductors. A single Model 2 crossover weighs 34 pounds. All of the speaker's components can be replaced in the field, so future upgrades can be accomplished in the home by the owner.

What is your preference in music? What do you use in designing your products? Rock, jazz, classical?

I like most all kinds of music, except for Country & Western, Rap, Hip-Hop, and Easy Listening. I'm equally at home with a Bach pipe organ fugue, symphonic music, heavy metal, industrial, even Kraftwerk. I like to push a system to its limits, since that's what I hear during a live event. Our greatest problem today is the very poor choice of recorded music. There's good stuff out there, but it's in the minority. Even the best digital sources seem to have real limitations.

What separates Gilmore from the rest of the companies out there?

Perhaps it is much like Apple said so many years ago, "We think different." Please understand, I don't own any Apple products. I'd be happy if the world ran on UNIX. You see, I really do think different. Perhaps it's because I was born in Berkeley. If it's mainstream, I run the other way. Since no other speaker technology brings me close enough to the live musical event, I reject what's been done in the past and do my best to start fresh.

Is there any other speaker that makes you think, "Gee, that is a really nice speaker"?

You do like to ask the difficult questions! I wish I could give you a good answer. I can, however, talk around your question, hoping it will go away. I've never found a dynamic speaker system or speaker driver that I like. I believe that this is mostly due to too much mass, poor dispersion characteristics, and unwanted resonances. This eliminates all but about ten percent of what I'd call the speaker companies that have potential. I've already expressed my preference for line-source dipoles, since they come closer to the dispersion I hear at a live event. There are some nice speakers, but every one of them exhibits severe resonance problems, poor dynamic range, and too much distortion. Did I avoid answering this question successfully?

You seem rather humble, whereas many designers see themselves as a cut above the rest of us mere mortals. I have spoken to too many who find nothing and no one equal to their designs and products.

You are too kind. I don't know about this mere mortal stuff. It seems to me that this is what keeps us all humble. No matter how hard I try, or how much time I spend, it seems that my efforts are nothing more than a work in progress. There's always so much more to do and so much more to discover. There are many more mistakes to be made before real improvements are realized.

What is next in line for Gilmore?

I'm working on the Model 4 prototypes now. This is a monitor/bookshelf design that has been a real challenge. It has not been easy to scale down our technology. I also have a Model 1 on a back burner. This is a cost-is-no-object monster that will not even fit in my living room. Still, I must revisit this effort, just to see what can be done. It will be our flagship some day.

I'm also working on some very unique and unusual electronics. I've always wanted an amp and preamp that could take the best advantage of the speaker's capability. I'm not quite ready to divulge what I'm doing in this arena quite yet, but you can be sure that it's something very different, much like the speaker project.

How do you picture the future of high end audio in the next ten to twenty years? Will our children be after the same things we are today?

My crystal ball is very dusty, but I'll see what I can do. I believe, and sincerely hope, that there will always be a niche for the state-of-the-art reproduction of the live musical event. This is my primary push and my motivation. I hope I will never see the rug pulled out from under my first love.

Still, I can't ignore the marketing machine behind home theater and portable electronics, such as the MP3 players and the like. Although I'm convinced that the concept behind using a home theater system to reproduce music is critically flawed, I can't deny that a good HT system can be great fun for watching movies. Perhaps it's these portable players that will keep two-channel alive in the years to come. I must admit that I've hooked up one of the more popular players to my reference system, and was amazed at how well it performed at its highest data rate. I've also heard that our speakers perform very well in HT applications.

Will our children still be after the same things we are today? I think so, at least at some level. For me, music comes first. It was playing my favorite instrument that started this whole audiophile thing. I'm convinced that future generations will always be hooked on playing music and on the wonder of the live event. I'm convinced our best neural research scientists are right, and the need for music is genetically programmed into our brains. I'm greatly encouraged by the kids in my neighborhood. They all tell me that they attach themselves to their portable players because they love music. Some of these kids play an instrument of some kind. This is our future.