The Piega Coax not only fits wonderfully into beautiful living rooms, it is also an absolute highlight in terms of sound. The price: 14,900 euros per pair (Photo: Piega)

Aluminum floorstanding speaker with ribbon coax: a test of the Piega Coax 611

I have been following the history of Piega since its beginnings. And of course, as a proven ribbon fan, I was very pleased that the Swiss (at least in the tweeter) consistently applied this principle. I was almost electrified when company co-founder and developer Kurt Scheuch came around the corner with the idea of a coaxial ribbon midrange tweeter. How cool was that…?! In fact, this stroke of genius catapulted the Swiss technologically into the world elite of loudspeaker construction for many years. This legendary coaxial driver now has a successor. And what can I say: with the GEN2 version of this exceptional driver, its sonic advantages are even more clearly audible. We tested the new Piega Coax 611. And in terms of sound, it’s a high-flyer.

Piega Coax 611 in the LowBeats listening room
A truly discreet appearance despite its height of 1.17 meters: The Piega Coax 611 once without cover plus base construction, once with cover and without base (Photo: Piega)

The special features of the Piega Coax 611

Let’s start with the housing. As usual with Piega, it is made of aluminum and has the characteristic boat shape, which has proven to be particularly acoustically advantageous not only for Piega. And the Coax 611 looks just like one of its predecessors. However, Piega designer Stephan Hürlemann has lowered the hull slightly. This makes the proportions appear more harmonious.

Piega Designer Stephan_Huerlemann
Stephen Hürlemann has stood for discreet design at Piega for years and has managed to make the new Coax line even more coherent. This harmonizes perfectly with the likewise extremely coherent sound (Photo: Piega)

The thickness of the housing walls is five millimeters, that of the baffle eight millimeters. The rigidity is therefore enormous – in any case much higher than with the MDF usually used. The shape and individual reinforcements on the strand additionally increase the strength. The workmanship – you can feel it at every point – is absolutely top.

Piega Coax 611: Enclosure + damping
The shape alone is acoustically favorable. The resonances in the rear section are tamed by additional damping material (blue); (drawing: Piega)

As with the US-American high-end Magico, the Piega cabinet is placed under tension and the metal dividers are firmly screwed to the cabinet. This significantly reduces possible resonances. Combined with sophisticated damping using acoustic mats, the result is a virtually perfect enclosure. If you do the classic ankle test, all you hear is a perfectly muffled “thud”. That’s how it should be.

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Piega Coax 611 Processing
Brushed aluminum with a perfect finish. The Coax 611 from above (Photo: H. Biermann)
Piega Coax 611 Structure
Piega calls the cross bracing “Tension ImproveModule” (TIM) and these are high-precision metal parts that are firmly screwed to the housing (Photo: Piega)
The base construction is just as perfect as the entire speaker: it virtually hugs the speaker and gives the slim column a much better stand (Photo: H. Biermann)
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The central component of the Piega Coax 611 is of course the ribbon-based mid-high coax. This is a fairly large (but extremely light) oscillating surface with a separately controlled and narrowly corrugated foil in the center. The advantage: the tweeter and midrange are on exactly the same axis. These are the best prerequisites for precise spatiality.

Piega Coax 611 Beauty
The new GEN2 coax is a masterpiece and is presented here in the right light. In the Coax 611, it takes over the entire range from 450 Hertz. The crossover frequency between the midrange and tweeter is 3,500 Hertz (Photo: Piega)

The GEN2 generation is still very young and has been improved by the new Piega development manager Roger Kessler according to all the rules of the art. Unfortunately, I didn’t have a speaker with “old” coax available for the test. But I’ve heard so many of them that I’ve been able to see progress perfectly. And the progress is also visible on the outside:

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Piega Coax GEN2 vs GEN1
Above the front panel of the first coax, below the front panel of GEN2. The front panel of GEN2
is 1 millimeter thicker and softly glued to the magnets. This effectively dampens resonances (Photo: Piega)
Piega Coax GEN2 vs GEN1
And this feature also makes it easy to tell them apart: GEN1 has an additional magnet above the tweeter foil (Photo: Piega)
Piega Coax GEN2 vs GEN1
And something has also changed on the back of the foil: GEN2 works with an additional (black) damping foil (Photo: Piega)
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All these measures together result in a system with significantly lower resonance and correspondingly higher sound pressure reserves. Here it is the comparatively small woofers that limit the maximum level of the system.

And this brings us to the third special feature of the Coax 611: the long array of woofers. Five of the 16-centimeter basses are lined up on the front. But what looks like a lot of bass power is actually a bit of a Potemkin village: from the front they look the same, from the back the lower three lack magnets – so they are passive radiators. These passive diaphragms have a similar function to a bass reflex tube and amplify the low frequencies in the lower bass range.


Although the Coax 611 is quite impressive at 117 centimeters, its maximum level remains at a rather average level. As mentioned above, the speaker is limited by the two woofers with a diameter of “only” 16 centimeters. For basses of this format, the maximum continuous sound pressure level of just under 100 decibels is a decent value – especially as levels of up to 111 decibels are possible for short periods. But the size of the Coax 611 initially promises more…

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MTD Spectrum Piega Coax 611 @85dBC/1m
MTD spectrum Piega Coax 611 @85dBC/1m: The measurement at living room level shows the nice balance over the entire range (measurement: J. Schröder)
MTD Spectrum Piega Coax 611 @99dBC/1m
At this point, the diagram was labeled incorrectly: The 611 actually performs 99dBC/1m in the MTD spectrum (measurement: J. Schröder)
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In terms of impedance and phase, the Piega Coax 611 is simply exemplary. Linear curves and an impedance that is always above 4 ohms are ideal prerequisites for combination with any type of amplifier. As usual, we also did a run-through with tube amps – in this case a Fezz Audio Titania with 2 x 50 watts (price: 2,600 euros). There was nothing to complain about: It just sounded wonderfully fine.


Impedance profile Piega Coax 611
The impedance profile of the Piega Coax 611 shows pleasing and unusual linearities in terms of impedance (red curve), phase (blue curve) and EPDR. Amplifiers particularly like this kind of electrical behavior (Measurement: J. Schröder)

However, we recently added the large Canor pre/power amp combination Hyperion P1 + Virtus M1 to our listening room as a reference amplifier. And it sounds so convincing that you no longer want to switch to the smaller amps… And there’s another point that rounds off the Coax 611’s thoroughly convincing performance: Because its bass is tuned more for clean impulse than for cozy fullness, I had no problems at all when setting it up. Even quite close to the back wall, the Swiss column just sounded good.

Hearing test

Piega had kindly provided us with a pair of well-recorded Coax 611s and so the magic of these speakers began to unfold as soon as we unpacked them. It all sounded so right from the start that I couldn’t tear myself away for hours.

Most hi-fi enthusiasts have probably already heard the advantages of a ribbon tweeter. There is something incredibly natural and easy about it. The same principle pulled down to 450 Hertz is overwhelming – at least when it is implemented well, as with the Coax 611. What makes this speaker stand out, however, is the absolutely harmonious combination with the two 16-centimeter basses. There was not even the hint of a break here.

Actually, I don’t want to start this discussion about a relatively heavy bass cone in combination with ultra-light mid-high foils. There are many speakers that sound inhomogeneous because of this dilemma. But there are also a number of counterexamples. Like the Coax 611, for example, where this transition is simply perfect. The cone mass of the 16-centimeter basses obviously still seems small and fast enough to follow the extreme impulse accuracy of the Coax GEN2.

Piano music reliably separates the wheat from the chaff here. The Ambient Jazz Ensemble has almost always been on my listening list recently. And with Jazz Face, the Piega immediately made a statement: the effortless way in which the individual piano strokes sparkled out of the loudspeaker and the absolutely seamless way in which the saxophone and the entire brass section played over it was simply breathtaking. And the whole thing is accompanied by an always clean, accentuated bass. I had never heard this music so coherent, so real. Or “Wendekreis des Steinbocks” by pianist Wolfgang Dauner (*1935 – †2020), where there is a wonderful dynamic interplay between the very high and very low registers. The Piega demonstrates such a seamless transparency that it is hard to imagine a more coherent sound.

Another thing I like to test is a reading by Wiglaf Droste, who has sadly also passed away. “Herbert kann nicht tanzen” (“Herbert can’t dance”) is a funny and biting look at Herbert Grönemeyer’s (German singer, musican and actor) concerts. The microphone is very close, the audience is sitting right in front of him and you can hear every laugh and every clap.

It is outstanding how precisely the Piega brings out all the details and yet remains absolutely stress-free. Everything comes across smoothly and effortlessly, without the mids or highs being emphasized in any way – something you often hear with other speakers that suggest such midrange transparency. What we still need to talk about is the musical illustration. If you already have a driver as ideal as the coax, the spatiality must be almost perfect, right? It is. The individual voices or instruments may not be very large, but they are portrayed extremely vividly. That also seems absolutely right.

Tannoy F 703, Perlisten TN15, Burmester B28. Piega Coax 611
Met in the LowBeats listening room: The Fyne Audio F703, the Perlisten S5t, the Burmester B28 and the Piega Coax 611 (Photo: H. Biermann)

And how does the Coax 611 compare to the competition? Outstandingly good. The picture shows four loudspeakers in this class that Piega had to deal with, among others. The slender Swiss woman proved to be the most discreet. The Fyne Audio may be a touch more boyish over the entire listening range, but it is brutally dynamic. For fans of loud jazz or rock recordings, there is hardly anything better. The Perlisten is also extremely impulsive, but its focus is clearly in the middle: hardly any other speaker shows so much energy and so much detail here. It quickly becomes clear that it is intended to bridge the gap to home cinema.

The Burmester B28 is possibly the toughest competitor to the Coax 611. The Berlin model, which also has an outstanding finish, sounds a little snappier and more precise, more impressive with hard-hitting snare and bass drums and also delights with a wonderfully open sound. And like the other two, the B28 outperformed the Piega in terms of level. But that doesn’t change anything: the Piega is second to none when it comes to this detailed fine silkiness, this continuous homogeneity across the entire listening range. That is simply great.

Conclusion Coax 611

This floorstanding loudspeaker simply thrilled me. It’s not just the best Piega I’ve ever heard: Because we’ve had (and still have) quite a few speakers in this class on test in recent months, I can also say with certainty that the Coax 611 is one of the best deals under 20,000 euros. I haven’t heard such a discreet performance and such a high level of tonal sophistication for a long time, and I don’t know of a significantly more expensive speaker that would really be better in terms of richness of detail and harmony. Added to this is the perfect workmanship and electrical simplicity that should please any amplifier. If you don’t want to drive brute volumes or fill huge halls with sound, the Coax 611 is a dream sound transducer for life.

Piega Coax 611
Test result: 4.7
Sound Quality
Build Quality


The rating always refers to the respective price category.
Extremely harmonious, natural, open and precise sound
Absolutely uncomplicated electrically
Easy to set up
Outstandingly good workmanship, excellent solid housing

Piega SA
Bahnhofstr. 29
810 Horgen / Switzerland

Pair price (manufacturer’s recommendation):
Piega Coax 611: 14,900 euros

Technical data

Piega Coax 611
Concept:3-way floorstanding speaker
Fitting:2 x 16 cm bass, 3 x 16 cm Passi-Radiator, 1 x MHT coaxial ribbon
Special feature:Aluminum housing
efficiency (@2.83 V/1m):84.6 decibels
Maximum level (permanent/short-term):
99 / 111 decibels
Minimum power for max. level
125 watts per channel
Dimensions (W x H x D):117.0 × 21.0 × 31.0 cm
45.0 kilogram
All technical data

Teammates and opponents:

Test floorstanding speaker Fyne Audio F703: the original power
Test pre/power amp combination Canor Hyperion P1 + Virtus M1

More from Piega:

Test Piega Ace 30 Wireless: modernized confederates
Test floorstanding speaker Piega Ace 50: the epitome of the living room speaker
Test floorstanding speaker Piega Premium 701
Installation: the hidden home theater with Piega
Test Piega AP 1.2: the high-end mini speaker

Autor: Holger Biermann

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Chefredakteur mit Faible für feinste Lautsprecher- und Verstärkertechnik, guten Wein und Reisen: aus seiner Feder stammen auch die meisten Messe- und Händler-Reports.