Sound Science: The Art of Speaker Design

Back in high school when I was trying to milk the most out of my Beatles, Hendrix and Charles Lloyd LPs, a friend showed me how to yank speakers out of old radios and connect them en masse to create a more impressive array than that provided by the typical ’60s suitcase stereo. Within no time I had six or seven three- and four-inch speakers mounted, naked, on a large sheet of crummy wall paneling, wired into my compact Sylvania.

With some trepidation I switched it on, and instead of blowing up or shooting flames, the contraption worked! Yes, the sound was bigger, but as we have all learned by now, bigger does not necessarily mean better. In fact, it sounded pretty crappy. The million details involved in speaker design were way beyond my comprehension of the time.

It might not be brain surgery, but speaker design is a science based on physics, electrical and mechanical engineering, all blended with what some consider a good dash of voodoo. Anyone in the speaker biz today will tell you, as in building any type of musical instrument, good speaker design is also a mysterious art-intuition and the ear often lead to the winning solution far more effectively than a crafty equation. Playing by ear is as valid in this form of music making as on the performance side.

“If you come from an electrical engineering background and look at our crossover, you’d say it shouldn’t work,” says Adrian Butts, president and principal designer of Ottawa’s Tetra Speakers (Tetraspeakers.com). “Early in our design process, I went to the library and read all the white papers and books on speaker design. After reading tons of those, I decided that, if those were the things these experts say you have to do, then we would do something else since the speakers they were building just didn’t have it.”

Vince Bruzzese, president and design chief at Totem Acoustic of Montreal (Totemacoustic.com), shares a similar experience. “When we introduced our first speaker in 1988 or ’89, the Model One, people laughed at it. ‘How can you get good sound from such a small volume,’ they said, referring to the cabinet size. Well, we discovered that a small volume is an ideal volume if you know how to control it.”

But the speaker is a means to an end: it’s the simple love of music that’s charged up these guys to do what they do. Bruzzese says that speakers make up about 70 percent of the equation in assembling a system, so it’s no wonder he gets excited when talking about a speaker’s ability to reproduce music accurately. “Music, in a few seconds, can transmit more information than a whole Encyclopedia Britannica. With just a few seconds of trumpet, you realize that music is the ultimate communicative medium. We want our speakers to extract that. A speaker is supposed to transmit the message from the musician as truly as it can to the end consumer.

“But when I was a consumer myself, I dedicated a sizeable portion of my salary trying to find components that could transmit the emotion of music, that could bring Jimi Hendrix, Billie Holiday, Led Zeppelin or Monteverdi as real as possible into my home. But most speakers just couldn’t do that. I felt ripped off as a consumer. Those speakers just couldn’t contribute to that emotional musical environment. No matter how good the electronics were, you couldn’t correct for the speaker at the end,” Bruzzese laments.

“A lot of speakers are built by engineers,” he goes on, “and though they have excellent technical training, they don’t have a scintilla of sense of what musical flow is, what the nature of musical energy is, of how the musical message is supposed to get through.”

Butts also talks elatedly about speakers. “As a kid, when I first heard my father’s Wharfedale speakers, I saw notes coming out of them. It was very clear,” he swears. “Later, it fascinated me how this paper thing could vibrate and create music.”

He also shares Bruzzese’s early frustrations with those speakers of the past. “It became a selfish pursuit [to find the right speaker], and following my passion, I ended up with an audio store,” he says. “I sold the latest and greatest speakers, but never felt that any of them were close enough to bringing real music into my room.”

In the search for a better, more true-to-the-music speaker, Bruzzese and Butts have followed different paths, each bucking mainstream trends. But one idea they have each explored, though in distinct directions, is the relationship of a speaker’s mechanical construction to that of musical instruments. Totem’s approach has often been to model a cabinet on the comparatively thin walls of wood-bodied string instruments such as guitars and violins, while Tetra, a name derived from tetrahedron, a shape often used in the company’s speakers, has stayed away from the more traditional rectangular box construction utilized by most manufacturers.

Butts asks, “Besides Bo Diddley’s guitar, can you name an instrument that’s a box? It’s just not the right shape for making music. They’re easy to make, but it’s the worst possible shape. The box just creates problems that you have to address, like very undesirable colorations. We keep the baffle, the front surface, as small as possible to avoid those kinds of audible distortions. At Tetra, you won’t find a speaker in a box and we think the results speak for themselves.”

Bruzzese’s thinking led to another approach. “In 1983, when I decided to build my own speakers, the norm for other high-end designers was to build a big heavy box to control resonances,” he says. “But I knew that a guitar or violin could make a very beautiful sound from a very thin structure. It became clear that the inert wall material of a heavy box was part of the problem because in such a structure, the resonances repeat themselves inside the cabinet, confusing the sound ultimately heard by the listener. To me, the ideal was to create a box that would quickly dissipate energy, that wouldn’t have those resonant tones repeating themselves continuously in the box, thus creating a more coherent aural experience for the listener.”

But a good speaker is a complex critter, more than just a fancy cabinet.

What, then, goes into a good speaker? Butts says there are three basic factors. “It’s a careful orchestration of drivers, crossovers and the cabinet. The goal is to achieve as close to a sensation that is just like being there-in the studio, or in the club or onstage. You should get a holographic, 3D presence. A speaker should allow you to suspend all disbelief-you can close your eyes and say ‘I am there. There’s nothing between the instruments and me. I’m not hearing the speaker, I’m not hearing the system, I’m hearing the music performed in the comfort of my own living room.”

Bruzzese says, “A speaker has to deliver imaging, emotion, have point-source control [meaning all the drivers blend to sound as if there is only one source for the sound waves, just as with a musical instrument]. It has to become part of your environment so you want to get back to it and listen to it every day. We work very hard at getting that musical message across through our speakers. We know what the plink of a piano sounds like, we know what the strumming of a guitar sounds like, and know all the micro-harmonics that result from the blowing of a horn. We try to duplicate those things in our speakers. That’s why we are always listening to live music.”

In support of the music, Totem has been actively involved in the Canadian jazz scene on many levels. He also sends each Totem speaker buyer a CD, which typically features Canadian jazz players, in gratitude for their purchase.

Totem has earned a reputation for designing speakers that excel at their respective price points, typically lauded for shining well beyond speakers costing much more. This comes from Bruzzese’s thoughtful and original designs and meticulous attention to detail.

He typically takes as long as two years to perfect a new design-a process that includes building 10 or more prototypes, changing minute details along the way until the perfect, natural sound is achieved. Construction of even the relatively inexpensive $950 Rainmaker model takes five hours of intricate cabinet building and more than two hours to assemble the crossover electronics, which don’t use printed circuit boards but are completely hand-wired. Drivers are carefully selected for each model to achieve what Bruzzese calls a “magical blend” so that it is impossible to tell where the woofer hands off the music to the tweeter. To further control unwanted resonances, Totem paints all internal surfaces with a highly stable and very expensive borosilicate coating, the same substance used on space shuttle tiles. “We use some very exotic parts,” Bruzzese says, “and go to what others might consider ridiculous lengths to give the listener a musical experience, but we believe our speakers can do things no other speaker on the planet can do.

“We don’t work with the same economic ratios as other companies,” he continues. “We could get a similar box made for us at a 10th of the cost, and it might look close to ours but it would never sound the same. We labor hard to give the consumer maximum value and sound for their money, and for the product to remain stable for 30 to 40 years.”

Tetra designs also take up to two years and involve the same sort of piece-by-piece trial and error method used by Totem. “I can spend years listening to different parts-capacitors, resistors, wire and so on-to see how they affect the sound,” Butts says. “Once I build a prototype, if there’s any hint that you’re listening to a speaker, it’s not ready. I don’t want a speaker that calls attention to itself.”

Butts also tunes his ears with regular doses of live music and says jazz is one of the best gauges of good speaker design. “It’s made for home listening,” he says. “Jazz has such a wide range of textures and fabulous interplay. To delineate that in the way the musicians intended is a real test of a musically accurate speaker.”

Apparently he’s onto something. A number of jazz luminaries have converted to the Tetra experience, including Herbie Hancock and Dave Holland, who says, “They’re the kind of speakers that have made me want to go through my entire record collection and hear them all again.”

Benny Golson, whose ears stretch back to the bebop era, has recently picked up on Tetra’s musicality. He calls them “the miracle” and compares the new clarity he can hear in the music to the clear vision he has now due to recent eye-cataract surgery. “I sense I’m on the bandstand. It seems like a band is in the room playing. These speakers are bringing life to my life,” he says, referring to the enhanced accuracy he now enjoys when listening to his old recordings.

Noted audio engineer Steve Hoffman has even installed a pair of the Tetra 505LTDs in his studio. Working on a remastering of Art Pepper’s classic Smack Up album, he says, “I’ve heard this music a thousand times, and I thought I knew it. But now I’m hearing things that get lost in the cracks of other speakers. And the fact that they are a true eight-ohm speaker means I can use a low-powered tube amp and still get the sound I want.”

Some long-term auditioning of two models each from Totem and Tetra confirms that these designers have attained their goals.

The Totem Rainmaker is a smallish bookshelf speaker that offers astonishing performance for its size and price. You get bass that seems impossible from such a small box, and the resolution is captivating. Like all Totem products, the fit and finish is second to none. Bruzzese says the company uses only veneer from the heart of the tree, which is more costly than solid wood. Still, these speakers are a true bargain.

A bit up the price scale is the Totem Hawk ($2,450/pair), a speaker my wife immediately fell in love with, declaring she liked it better than the $6,000 speakers we own. The Hawk takes the performance of the Rainmaker and notches it up considerably, including more detail and more bass. But there’s absolutely nothing boomy or false about it; rather, it has the accurate, tight, punchy bass that many speakers wish they had but don’t. Like Bruzzese, I’m a Hendrix fan, and to test these out, I cranked up a few selections from the purple box set The Jimi Hendrix Experience. Playing a live “The Wind Cries Mary” did in fact put the guitarist in the room. The crackle and pop of his Marshall stacks came across as if I were hearing them live, even in spite of the relatively crappy recording.

The Tetra loaners were equally enjoyable. The company’s new 120U ($1,500/pair) is a bookshelf design that is also being promoted to the pro side for use as studio monitors. Like all Tetras, the 120U produces a level of detail that seems like an audio magnifying glass is directed at the music. Little things come into focus-a stick on a cymbal, a hammer on a piano string-the minute cues that define the sound of a particular instrument come into focus to help convey a convincing re-creation of live music. Tetra recommends these for smaller rooms, and within that context they deliver the same basic sound as the larger models do in larger rooms. Expect highly dimensional and highly accurate reproduction.

The Tetra Live line includes speakers intended for larger rooms, and the 405 ($4,750 to $5,250 a pair, depending on finish) is second to the top of that series. What do you get for the extra bucks? Well, you get a slightly more developed sound, a fuller sound than the 120U because of the scale, and richer bass because the physics of the larger driver and larger cabinet allow for noticeably more bass extension. But many of the same qualities are there. I could sit four feet from the left of center and still hear the right speaker perfectly; the stereo image was not impaired in the least. And like the 120Us, the 405s are also transparent, a quality achieved primarily by a lack of coloration that allows a clear view into the recording venue. I listened to a 1961 recording by Red Garland, Bright and Breezy, and it blossomed into the living room with a vitality that’s difficult to describe. The 405s allowed ample evidence of that beautiful session to come forward in a most natural manner.

Speaker design is a complex art. It’s sure a lot more than throwing some drivers into a box-or hanging them on wall paneling.