Floor Loudspeaker Reviews

Sidebar 1: A Visit to Switzerland

Piega is headquartered in Horgen, Switzerland—a fortuitous fact, because in mid-May, two days after the High End Munich audio show ended, I was scheduled to interview Yello's Boris Blank in his Swiss hometown of Zurich for an upcoming music feature. Horgen is just 20 minutes from Zurich by train. So, not a bad schedule: High End Munich on the weekend, a factory visit to Piega on Monday (footnote 1), and a Tuesday spent with the creative wizard behind Yello. That's four days' worth of catnip for audiophiles. It's a tough job, but someone's gotta do it.

Horgen is a tidy, upscale town of 23,000 people situated on the western bank of Lake Zurich. There are phenomenal views of azure waters traversed by small boats and yachts, with the snow-capped Alps beckoning in the distance. Inside Piega's lakeside building, I met Roger Kessler, the amiable and driven head of research and development, and asked him about the company's accomplishments and plans.

Piega's Roger Kessler on ribbon technology: "Ribbon drivers have serious advantages over conventional speakers. They operate on a similar principle as dynamic ones: a current flows through a coil situated in a magnetic field. The resulting Lorentz force generates a mechanical vibration that's converted into sound. A significant difference is in the arrangement of the magnetic field: in a ribbon, the magnetic field extends uniformly across the whole driver. This allows for even distribution of force on the diaphragm and allows the diaphragm to be much lighter than in conventional drivers. A midrange ribbon typically weighs less than a gram, which, combined with the high magnetic strength, results in an excellent weight-to-performance ratio. The result is a fast impulse response that tops what conventional midrange drivers can achieve.

"Another big advantage is that the diaphragm in a ribbon always remains within the magnetic field. That means that the force remains consistent regardless of the diaphragm's position. By contrast, with dynamic drivers, the driving force varies depending on how deeply the coil penetrates into the magnetic field, leading to modulation of the output signal.

"Ribbons also have a strictly symmetrical suspension, enabling uniform movement of the diaphragm in both directions, forwards and backwards. Standard drivers typically exhibit asymmetrical vibrations.

"Also, while coils in conventional drivers can heat up significantly during use, which can cause performance losses, ribbon drivers have pretty much no thermal issues."

On the Piega 811s' improved coaxial driver: "A new central front magnet enhances magnetic flux and efficiency. We've also reinforced the front plate and added cross-braces to dampen microresonances. An additional damping layer in the midrange region on the back of the diaphragm improves linearity from around 400Hz, plus it facilitates integration with the woofer and lowers the resonance frequency."

On tuning Piega's products: "The tuning of our speakers is an iterative process that begins with a simulation of the enclosure and drivers. Then we derive a basic frequency crossover that forms the basis for the tuning work, which involves alternating between measurements, listening, and adjustments. Once we reach a certain level, the crossover is physically built and tested in various rooms. All in all, I'd say that we measure 25% of the time and listen the other 75%. We do the listening independently from each other because we don't want another person's opinion to influence what each of us hears. We typically put off comparing notes until each team member has had a chance to form an opinion independently."

On choosing amplifiers: "I definitely lean toward transistor amplifiers rather than tube amplifiers. Not that there aren't excellent-sounding tube amps, but the impedance curve of our speakers simply matches better with the characteristics of a solid state amplifier. Class-A amps sit at the top of my list, but high-quality class-D amplifiers harmonize very well with our speakers as well, especially since we don't use extremely low impedances.

"A high damping factor is advantageous but not strictly necessary. From a factor of about 20 onwards, you're well positioned. More doesn't hurt but isn't required. In fact, we've noticed that with certain amplifiers that have very high damping factors, the midrange can sound a little lean."

On Piega's future: "Looking ahead, I sense that selling component systems—essentially a pile of boxes—may get more difficult in the markets we serve. Our clients appreciate elegant, uncomplicated solutions, so I can see us exploring more all-in-one active systems. It's a road we've already gone down with our Ace Wireless and Premium Wireless Gen2 models. One of the big pluses of developing active systems is that we have the whole thing under control. I mean, suddenly we can choose the amplification and match it to the speakers, and electronically correct for anomalies both in the end user's room and in the way that we integrate our drivers. I think we've come far, and it's only going to get better. But it's not our goal to grow by leaps and bounds. Growth is great, but we will not sacrifice quality to it."—Rogier van Bakel

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Footnote 1: Disclosure: The company bought me dinner, but I bore all other expenses, including hotels and the transatlantic flight.