he Isis is the largest speaker in the Trenner&Friedl "Egyptian" sub-series, which also includes the Pharoah, reviewed by “High Fidelity” in February 2014, and the smaller Ra that is actually higher in the line hierarchy despite its size. Trenner&Friedl also offers the less expensive Dizzy and Art, and the flagship no-compromise modular Duke, selling for just a bit less than 600,000 PLN. Against this background, the 95,000 Polish zlotys for a pair of the great looking, classically proportioned Isis may seem like a downright bargain. After all, it is the top high-end we are talking about here.

Leaving aside the name game and looking at the design, it turns out that there is no other similar product in the Austrian manufacturer’s product lineup. The cabinet resembles a medium-sized wardrobe, and to me personally it is reminiscent of a ceramic kiln control cabinet, which was my diploma project in high school. The speakers’ weight matches their looks, and they tip the scales at 65 kg (each). When two nice men (that’s right, two of them!) arrived at my doorstep and hauled in two huge wooden crates to slide the Isis out not without much effort, I let out a weak moan, figuratively speaking, that is, since ‘boys don’t cry’! I could not really imagine how, after putting them on spikes, I would be able to move them around to find the best positioning for them.

So I asked to put them on felt pads, in my mind already seeing myself gliding along with them on the floor, without much of an effort. If I only had a bit richer imagination, I would have associated the way the woofer is loaded in the Isis with the Pharoah (and the Ra) design, and drawn the only right conclusion: the bottom panels of both designs feature two outlets of the system that loads their big woofer. The distance of the outlets from the floor is, therefore, very important because it determines the lowest bass propagation. Hence, when placed directly on the floor, the speakers sounded a little too dull. Two centimeters of clearance between the bottom cabinet panel and the floor, provided by the spikes, completely eliminated the problem.

The massive weight and size of the Austrian design result both from the cabinet design, which uses thick, multi-layer plywood, as well as the drivers used. The speakers look extremely traditional and, at the same time, "proper." This may be due to the fact that their dimensions are in the golden ratio i.e. the height to width ratio is the same as the ratio of their sum to the width. The ratio is also called the "golden number" and its value can be rounded to 1.618

The 380 mm woofer is one of the largest woofers that are used in home audio systems, though there are not too many equally massive drivers even in professional audio. It has a traditional paper cone, with characteristic ribbing to improve its stiffness, a huge magnet and massive cast basket. As I have mentioned earlier, in the Isis it is loaded into a system that we already know from the Pharoah. It is a combination of "bass-reflex and classic horn," to quote the words of Andreas Friedl, half of the Trenner&Friedl duo.
The midrange driver is very large, too; larger in fact than a woofer used in many floorstanding loudspeakers. It also has a paper cone, this time reinforced with fiber. It is loaded into its own chamber, which is not sealed, though. The rear panel of the chamber features drilled out holes, which suggest the presence of some kind of passive radiator. And then there is the horn loaded compression driver with a titanium diaphragm. We have heard it before in the Pharoah, but it is also used in the modular Duke.

The speakers eventually ended up in the same exact spot as my Harbeth M40.1. If your speaker cables come with stiff and long connectors, the location of the speaker terminals in the Isis may be problematic. The quality copper Cardas terminals that are used here have a specific design and only accept spade connectors plugged in straight from the top or bottom. They are tightened with a single screw, which results in an even pressure. However, the terminals are located quite close to the floor, which is why I just barely managed to fit the spades of my Tara Labs Omega Onyx cables. Eventually, I put the speakers on the stock spikes, and those in turn on spike receptacles from Acoustic Revive. The speakers were positioned directly at me.

The Isis are equipped with black grilles mounted on a wooden frame. They are fitted so as to form a whole with the front baffle. The speakers look interesting without the grille, too, as then you can see the drivers and large, wooden front baffle. It is surely a matter of taste, but I liked them more without the grilles.

Have you ever wondered, what is the aim of audio manufactures in designing and then producing better and better components, speakers and accessories? Besides making money, that is, which is completely natural – we all work to make money. What do they want to achieve, what do they aim for? The answer that suggests itself is that they want to achieve an even better sound. This is a reasonable observation and one could stop there, were it not for another "obviousness": how to define the "better" sound and how is it characterized? "Better is just better," that’s it, which is actually true here. However, audio is a field full of trade-offs and design choices, whose result is a product being a combination of science and art, and hence by definition ambiguous. If a recorded event could be perfectly reproduced or copied, that is shown the same way it had been in the time of the recording, there would be no problem and everything that approaches that ideal would be "better", and whatever departs from it would be "worse."

Unfortunately, in this respect the high-end is no different from audio equipment that sells for $300. This is in spite of the fact that the sound obtained from a properly set up audio system, which includes quality components, is incomparably better than that of a budget system. From the high-ender's point of view we are in heaven. However, since we start from a completely different level, the differences that can be noticed after upgrading any of the system components to a $20,000 more expensive one have as big an impact on the way we perceive music as those resulting from replacing a $300 amplifier for a $600 one.
Pitting against each other the Isis and my reference Harbeth M40.1, which together with custom-made Acoustic Revive stands cost exactly the same as the Austrian floorstanders, was therefore a journey into the world of ambiguous choices and unambiguous changes. Plugging in the Isis instead of my Harbeth M40.1 brought significant changes in the many aspects of the presentation, changing the sound of my system. While both speakers have more in common than what separates them, the differences are very clear and it will not be difficult to pick up your favorite pair.

To be honest, let me say that in many respects the Isis were the best speakers I’d ever had at home. For example, I’d never heard such a good soundstage. The speakers offer outstanding holography, showing a fully credible soundstage. My Harbeths are excellent in this regard, and other speakers that behaved fantastically include the Amphion Krypton3 and the Franco Serblin Ktêma. Nevertheless, the level of holography showed by the Isis was unbeatable; the best I’d ever experienced at home.

I have long been irked at hearing a stereotype that is prevalent in the audiophile world (and only in it; the "pro" audio world is free of it) and says that it is small stand mount monitors that present the best soundstage, and if we are talking floorstanders then only those with a narrow front baffle. I eventually let it go when I realized that many music lovers may actually be taking something else for it. What I mean is that small speakers, with narrow front panels and petite woofers, can mask soundstaging problems. It is true that they can help bring out the edges and emphasize them. And that is, I think, what is usually perceived as "a clear soundstage." Well, it is not. The true soundstage is holography, imaging and drawing instrument bodies. Monitors (almost all of them, but for a few exceptions) can only guarantee imaging.

If you want to become convinced of that, listen to the flagship Harbeth or better yet to the speakers under current review. The show the soundstage as a continuous space, in the shape of a sphere. It surrounds the listener without drawing attention to itself. Electronica albums, such as Jean Michel Jarre’s Essentials & Rarities, Aquavoice Memories or Morton Subotnick’s The Wild Bull, which has recently been released on vinyl, were shown from a new perspective. I’d never heard so well the sounds from behind and from the sides, nor had they been so independent of my room and the presentation in front of me. Early stereo recordings, like Coltrane’s Ballads, with the instruments extremely wide in the channels, they were super-independent of the speakers that simply disappeared. I just had to close my eyes. Coltrane's saxophone, placed to the far left side, was heard playing outside the outer edge of the left speaker, while the drum set on the right side sounded slightly outside the inner edge of the right speaker. As if these instruments were not associated with the source of the acoustic wave.

Such excellent soundstage, without a clear division between the acoustic planes and the instruments, between the reverb and the instrument, and yet with an amazing reliability, is possible - I think - thanks to very flat frequency response, great combination of drivers and extremely low bass.
For it is the bass that will come as a surprise to anyone who knows its sound, who listened to other large high-end speakers and who knows the sound of live instruments. It has an incredibly deep extension, which is most impressive with electronic instruments, the organ and piano. It is perfectly controlled even at the bottom end. It also provides a solid foundation for everything that is above. It differs from the Harbeth bass with a different way of shaping the attack – the British speakers are more energetic, more clearly focused sounds. And yet it is the Isis that have a better differentiated low range and that better display the differences in the recordings, the latter always shown a bit nicer and prettier by the Harbeth. Most importantly, however, the bass provides the basis for building up the instrument bodies and whole structures.

The treble and midrange are one and the same, forming a whole. Horns have a bad reputation because most of them are just low-quality drivers, where the horn not only amplifies the sound but also any distortion. Flagship JBL, like the S3900, and now the Isis, show that it is possible to combine delicacy with resolution, selectivity with liquidity. All the more so that in the Isis the treble is part of the midrange, never sounding alone, detached from the rest.
And the midrange is dense, warm and big. The vocals have a huge volume. They are bigger than in reality, but it is not the fault of speakers from Trenner, or even Friedl. That is simply how you hear the vocals over a close-up microphone. The further away it is, the smaller it gets. There is also less bass, but even after adjusting it in the mixing console and achieving tonal balance, both presentations differ from each other with just that: the volume. The speakers only showed how to do a recording and brought out a particular recording technique. And it was very enjoyable.

Sitting in front of the Austrian floorstander duo we find ourselves in a bubble that includes a direct and surrounding sound, as well as the hiss of air in the recording studio and/or tape hiss. There is also a large volume, i.e. a close, warm, natural presentation, and a sense that the speakers do not have any restrictions in the bass department. That translates into a relaxed but at the same time compelling presentation.
At home, I listen in the nearfield, in other words closer than usually, to minimize the impact of my room on what I hear and to be closer to the sound sources, which I like. The huge Isis, standing close to me, put me in a situation similar to that experienced by audio journalists in Japan. The Austrian speakers did not disturb anything and there was no need to position them further away for everything to "settle down" and sound fantastic.

It is obviously obvious that there are no ideal speakers. The Isis, too, are only an attempt to present musical events. A successful and interesting attempt, but still an attempt. Even they cannot show everything that the Austrians from Trenner&Friedl are capable of. Otherwise, their flagship Duke, which sells for nearly 600,000 PLN, would be a fraud rather than duo’s attempt to implement all their ideas, with a no-cost objective. And fraud is the last word to occur to me while auditioning their second design from the top. Other flagship speakers simply also show something special and different than the Isis. We are talking about top high-end, but even here the customer’s taste is just as important as absolute quality. The more so that very often several different audio products offer a similar quality level.

The Harbeth have a somewhat narrower frequency response and are not as resolving in the treble. Their sound is, however, more dynamic and thus more colorful. The slightly “soup-up” all the recordings, so even weaker ones sound at least interesting. They do not do this through homogenization, but rather a slight "pause" before pointing finger of blame. The Isis are more explicit in their “assessment.” The Harbeth, the said Amphion and the Sonus faber Guarneri Evolution show more expressive bodies, denser and richer in texture. Although all of them are among the best speakers in terms of imaging, the Isis are even better, despite the fact that their focusing our attention on particular events, music (instruments, voices, etc.) is not as phenomenal. I think their objective lies in showing a continuous, consistent, huge soundstage. The Harbeth show it in a slightly smaller scale and are not as holographic.

Conclusion

This is one of the best speakers that I have heard at home. In terms of tonal quality and presentation they are reminiscent of the Hansen Audio Prince v2, which are still in my mind despite the several years that have elapsed since I reviewed them. The Austrian speakers combine it with a much better soundstage. When it comes to its size (the whole sphere, not just the tunnel in front of us), it is almost unrivaled. Their classic proportions and absolute conservatism with regard to their finish make them timeless. Just like their sound. They will sound equally well in a small and large room. Preferably paired with a powerful amplifier, be that solid state or tube. Truly magical speakers, hence the RED Fingerprint.

The Isis is a 3-way, 3-driver speaker design, to some extent similar to classic JBL speakers. They are related by using a large paper woofer and horn tweeter. Although the shape of the horn used in the Austrian speakers is of course different. The 45 mm (1.75-inch) compression driver has a diaphragm that is made of titanium coated with titanium nitride (TiN). It is loaded into an aluminum horn that has been designed by T&F and is made in-house. It is a very solid component machined from a single block of aluminum. The driver’s neodymium magnet has a heat sink mounted to its back.

The 200 mm (8-inch) midrange driver is the same as that used in the Pharoah, where it served as a midwoofer. It has a paper diaphragm reinforced with fiber and is custom made for T&F by SEAS, which also sells it as H1613-08. In Austria, the diaphragm is coated with six layers of Italian balsamic oil lacquer, used for soaking wood in musical instruments.
The true power lies in the woofer – I have seen similar drivers in the K2 and the Everest from JBL. Its diameter is 380 mm (15-inch). The cone features ribs that were characteristic in high-sensitivity drivers from years ago and were used to stiffen its surface.

The crossover employs high-quality components from Mundorf, like silver/oil capacitors and air-core inductors, as well as MOX resistors. Internal wiring is on Cardas cables. Pure copper speaker terminals come from the same manufacturer. There are two pairs of terminals, separately for the woofer and mid-tweeter. They are coupled via jumpers from the same Cardas cable as that used for internal wiring.

The cabinet is beautiful, made of multi-layered plywood finished with natural wood veneer (choice of several versions). The individual layers vary in hardness, thus helping to damp vibration. The interior is damped with sheep wool – the company claims that it comes from Austrian sheep…
The speaker sports a solid plinth that adds to the thickness of the bottom panel. It has a cut-out at the rear, to direct the air from the reflex port/tube system towards the wall behind the speaker. In spite of that, the Isis can be positioned very close to the rear wall and room corners, which I tested personally. The spikes are mounted to the bottom of the plinth. In my opinion, it worth replacing them with footers from Franc Audio Accessories or at least put them on spike pads from the same manufacturer.

Specification (according to the manufacturer)

Frequency Response: 28 Hz (-6 dB) - 40 kHz (-3 dB)
Sensitivity: 91 dB (2.83 V / 1 m)
Nominal Impedance: 8 Ω
Dimensions: H 1200 mm x W 500 mm x D 350 mm
Weight: 65 kg/each