June 2023

Piega Coax 811 Floorstanding Loudspeaker Review
Don't miss out on the fun!
Review By Michael Lange

  Close To Legendary – At the 2022 HIGH END audio show in Munich, Piega shone with the new Coax series. Roger Kessler, head of development, likes to compare the top model, the 811, to the Porsche 911. Rightly so?

Piega, located in the idyllic town of Horgen by Lake Zurich, is a family business, now managed in the second generation by Alexander and Manuel Greiner. The manufacturer has been the undisputed market leader in Switzerland in the field of high-quality speakers for years and has a firm grip on the global elite, who of course are also present there.

This not only stems from the Swiss attitude and the home advantage, but also from structures that have grown over more than 30 years: quality, reliability, and the regular "doors open day" for fans and people interested in the brand. And not to forget a network of loyal and reliable dealers who appreciate the advantage of having direct contact with the company and its development division.

Consistency And Progress
This has indeed not changed, even after the departure of the founders Leo Greiner – responsible for design and the business side – and Kurt Scheuch, developer. What has changed, in contrast, is the research and development work itself, which now achieves faster as well as surprisingly large advancements using the latest measurement technology. This highly modern technology can help to avoid some mistakes and to implement promising ideas more quickly, but it does however not render careful, elaborate development and extensive listening sessions obsolete. Piega developer Roger Kessler and his team tinkered with every conceivable aspect in order to catapult the Coax series a good deal further forward in terms of sound quality.

The first step was the housing. To give the bass more depth and higher power reserves with lower distortion – thus more clarity and punch –, it is slightly larger than that of its quasi-"predecessor" 711. Due to the increased volume, it also had to be reinforced in a different way. The aluminum extrusion of the housing is now subject to controlled tension, in order to eliminate vibrations. The shape of the cabinet has also been optimized from an acoustic point of view, particularly the rear sound component in the lower midrange is now absorbed better, as the Swiss manufacturer promises.

The two 22mm woofers manufactured by Seas according to Piega specifications are supported by two passive membranes of the same size per speaker. This arrangement is more complex and expensive than a bass reflex design, but brings sonic advantages according to the developers. This is why the drivers were adapted from the also still available 711, but have a different operating point now, because the new coaxial driver reaches further down.

However, the coaxial ribbon unit responsible for the midrange and treble is undoubtedly the most relevant as well as eponymous component. Resulting from a cooperation with a Swiss university, detailed analyses were carried out and the right conclusions were drawn for a major update. Thus, upon closer examination, nothing remained as it was. The mechanical separation of the magnetic rods was reworked and the front panel was stiffened with a horizontal brace. This enabled the use of a new type of adhesive that softly bonds the magnets, which aims to reduce resonances and further optimize the damping properties of the newly developed and specially coated foil. As we are told, this has the advantage that the frequency response of the driver could be linearized in its lower operating range, while the coupling to the woofer now happens at 470-480 Hertz.

As a result, this also reduces distortion, plus it increases the amount of details and resolution in conjunction with an even more natural reproduction of voices.

Efficient And Dynamic
There have also been some improvements in terms of efficiency. An additional neodymium magnet above the tweeter added a few decibels of efficiency, which is supposed to assist in improving the dynamic characteristics and impulse response. And don't forget: Each individual coaxial driver is manufactured meticulously by hand. If the person responsible has a bad day and does not work with the necessary amount of Swiss precision, the daily production inevitably fails – fortunately, this is only the case extremely rarely. Of course, however, it takes quite a lot longer to assemble such a complex driver by hand than to use a normal, mass-produced driver. And everyone who has ever been interested in a watch from this country knows that a product "handmade in Switzerland" certainly has its price.

Let's take a look at the crossovers working in the shadows: Separate circuit boards for bass and midrange/tweeter are used here. In combination with the cabinet properties, they are tuned to a Linkwitz-Riley characteristic. The midrange/tweeter part works with high-quality MKT capacitors and air core coils, while special electrolytic capacitors and iron core coils are used for the low-frequency range.

The update is therefore more of an all-round redesign, which is why naming it as anan MK-something version would also have been somewhat misplaced.

And with correspondingly high expectations, we went into the listening sessions. Of course only after the always necessary search for the optimal placement, angle, and distance to the listening position. We started with testing the impulsivity and reproduction of voices, for which we used an excerpt from the radio play "Der Himmel deck talles mit Stille zu" ("The sky covers everything in silence") by German public broadcasting station SWF.