„T“he Hyperion IV is a 2.5 way construction based on mid-woofers Visaton W170S and the SEAS H1212 tweeter with a dampening chamber. They have 4Ω impedance, frequency response 40-25000Hz and 89dB effectiveness. In the mid-woofer section I used an air coil, for the bass driver a core one. In the sound path only SCR capacitors were used. The price per pair of 4800 PLN is for the standard finish: walnut, sapeli, oak, cherry and beech veneers. There is a possibility to have them in any veneer available in Poland at an extra price, starting from 400 PLN.”

This is what Michał Kęcerski, the constructor, owner and moving spirit of the Lodz based company tells about his speakers. But when you enter the name Audio Academy into the “High Fidelity” search engine, you will get a lot of hits, especially in the questions and answers section. Because when I have to recommend someone loudspeakers with an open, quick sound, loudspeakers, that will sound well with almost all electronics, and which do not cost more than 4000 PLN, then one of the most often appearing options is the Phoebe III.
Those are very successful constructions based on a poplar Visaton woofer and a metal SEAS tweeter. Looking at the mid-woofer you could grumble about its “mediocrity”, because Visaton does not sound as proud as “Scan-Speak”, or even “Vifa” or “Peerless”. The thing is, that creating a successful loudspeaker using Tymphany drivers is by far not easy. I really sympathize with people, who think differently. This is the reason, that when I see an inexpensive loudspeaker using those drivers, my reaction is rather anxiety than admiration.

Anyway, the Phoebe III just sound as they should. When we supply them with sensible electronics, then it will be at least good. But the thing is, that audiophiles (I almost wrote people here…) chose more expensive speakers for more expensive electronics. Although logic dictates otherwise – it is better to use as expensive electronics as possible, and have the loudspeakers be the cheapest part of the sound chain, as long as those are good loudspeakers. But, like I said, some habits and beliefs are stronger than experience. And there is also the issue of bigger listening rooms, where the small Phoebe III are not capable of providing sufficient sound volume, and even if they can, then they are far from their safe zone, where the distortion is lowest. Enter the Hyperion. Available now in the fourth version, they are, to a large extent, the direct evolution of the idea of the Phoebe III – on the midrange and bass we have exactly the same Visaton driver, with a paper, varnished diaphragm, and on the treble, the well known, at least from the Harpia Acoustics Dobermann, metal dome tweeter from SEAS. This pair is accompanied by one additional driver – a second, identical Visaton, active only in the bass area, creating a 2.5 way system with the other speakers.
It is interesting, that its presence was not used to expand the frequency response – the lower border set on 40Hz (according to the manufacturer) is shared by both constructions. As is the 4Ω impedance. However the Hyperion IV are more efficient – this is 89dB compared to 87dB in the Phoebe III – but from experience I know, that you should provide them with a powerful amplifier. And the new loudspeakers are bigger, their dimensions are (WxHxD) 980 x 365 x 208mm, compared to 830 x 190 x 290mm of the Phoebe III. And the weight: Hyperion IV – 20 kg (a piece), a Phoebe III – 14 kg (a piece).

SOUND

I have to repeat what I wrote before: the Hyperion IV are the evolution of the idea behind Phoebe III, in this case also in terms of sound. If the latter were not to someone’s liking, also the now tested, more expensive model will stay in the same category, “not for me”. But when Phoebe III showed you their assets in an equally tempting way they did it to me, then it will be a completely different story…
I know from your emails, that in some systems the two-speaker Phoebe III sounded quite bright and aggressive. I think, that in most cases this was the problem of the system, I mean mismatched electronics, wrong loudspeaker positioning, power problems or cabling problems. In this order. But I also can understand, that in those people’s systems there was too much of the upper midrange. Because those loudspeakers, as well as the Hyperion IV do not lack that. This is the reason, that they require a bit more effort from the listener than taking them home and unpacking (what was not really easy in case of the tested speakers, because it is quite big…). But they will repay you with something, what other similarly priced, and sometimes more expensive loudspeakers do not have – selectiveness and cleanness. But I will start with something else, because this is something inherent for the sound of the Phoebe III and Hyperion IV, what is clearly the result of the choice of drivers – mid-woofers from Visaton and a splendid, metal tweeter from SEAS. I mean motility.
This is an element, which passes by, when it is treated properly. If it is not, then it seems that the loudspeakers sound slow, or that they have some problems. And the most common wrongdoer is motility, or rather the lack of it. And it is about the ability of playing quickly enough, so that the attack of the sound does not get flattened, that all phase relationships are intact, etc. And at the same time there is the ability to sustain the sound and quickly decay it, when the impulse is gone. Sounds normal, right? Well it isn’t – the majority of loudspeakers has some issues with that, larger or smaller, but still. For example the tested not so long ago Castle Howard S3, otherwise very nice constructions, have issues with that, especially the decay. This is the reason, that they have such a big bass, bigger than needed for the ideal tonal balance.
The Hyperion IV do not have any problems with that. The Visaton drivers are fast, although not dry. I would even say, that they have a slightly soft, slightly – let me say that – warm sound. And this combination of softness and precision makes each kind of music “flow” with this loudspeakers, that there is no impression of slowing down of the sound.

So I’ll return to the selectiveness and cleanness. This is of course not the last word in this aspect, my Harbeth are in a completely different galaxy, but in the price range of, let’s say, 10000zł, then in the area of extracting the individual sound sources, showing their distinctiveness these speakers are the forefront.

I know, because we listened with Michał Kęcerski to my Harbeth, that the creator of the Hyperion IV likes open sound. So this kind of sound aesthetics, which is presented by those loudspeakers, is the result of thought through choice, resulting from concrete expectations. This really results in an open sound. The metal SEAS tweeter is really splendid in that aspect. The sound of the discs is strong and clear due to this. If small bookshelf speakers would sound like that, the sound would be too “open”, in the sense, that the accent would be placed too much on the higher frequencies. But the Hyperion are big constructions, with two mid-woofers, of which one handles only low frequencies. This is the reason, that the sound has a strong foundation. The virtual sources are big, have a really large volume. And this is probably what Michał wanted, because adding of another driver did not really widen the frequency response. Yes, it goes a bit lower than the Phoebe III, the bass is more massive, but I think that this can be the result of the increase of the cabinet volume (resonance chamber for the bass-reflex), as well as the increase in the summed surface of the woofers. Like I said – this gets not translated into a big change in reproduction of the bass. It is nice, clear, but still not as massive on the bottom, and has not such a clear definition as the mentioned Castle or PMC OB1i (please remember, that those two mentioned speakers are twice as expensive as the Audio Academy speakers!). But – and this is very important – the tonal balance of the Hyperion IV seems more neutral, there is no clear domination of the bass like in the Castle or PMC.

Tonal balance, motility, cleanness and selectiveness are important assets of those loudspeakers. But maybe for the potential listener it will be more important, how the sound is built within the space between the loudspeakers. And it is built in an incredibly interesting way.
Like I already mentioned, the sound sources have a large volume. Yes, this is important, very important – the sound are big, the voices have clear contours, this is the mentioned selectiveness, but also a clear saturation, they have no edgy, unpleasant elements in the sound, meaning a too strong attack, dull and annoying. This is a part of something I already wrote about, namely a slightly round sound of the Visaton drivers. This is why the sound is nice and fluent, not catching the attention of the listener too much.
The vocals profit most from this kind of presentation, which is not dry or small. I had a lot of pleasure listening to the boys from the group Audiofeels, but also to the refined music of Josquin Desperez, performed by Alamire. Anyway – the guitars from the disc Caravanserai of Santana were also very good, as well as those from the recently issued singles collection of Goldfrapp. Less well recorded discs, like the mentioned The Singles Goldfrapp will sound higher, the accent will be placed a bit above 800Hz. This should be expected. But this will not be sharp sound. I checked that with a few discs of that kind, like the new compilation of Pet Shop Boys Format and it was not bad. To be prepared for everything, I mean not stroll though our collection, searching only for well recorded discs, and concentrate only on music, it is worth to think about electronics, which is warmer than usual. As long as it is dynamic and open – it is not worth to dampen, what Michał reached with his loudspeakers. Music Hall, NAD, maybe some tube amplifiers – I would go in that direction. It is also worth trying, how the loudspeakers behave placed on a wooden, 3-4 cm thick platform. I placed them for some time on a marble platform, then on the Acoustic Revive RST-38 and it seems, that although with both the definition of bass was slightly better, yet the tonal balance was better with the wooden platform. It is worth trying.

Summary
Phoebe III are for me the best loudspeakers made by Michał Kęcerski. The most successful. I would not change anything in them, however I otherwise know, that Michał wants to make a few improvements to them. This is a mature, good construction with a very good, rhythmical and free of coloration sound. If somewhere it sound sharp, bright, then in most cases this will signal some problem in the system, but not in the loudspeakers. The Hyperion IV are their evolution – they use the same drivers, they have similar looks (despite everything), etc. And they are more expensive. They sound better, in every aspect, maybe with the exception of the resolution of the treble. But this is not a breakthrough change. Their asset is a much bigger volume of the voices. The AA Hyperion IV fare best with small ensembles, beautifully showing the spatial interactions, depth of sound, big and wide sound stage, etc. And this is something the smaller Phoebe III cannot do equally well. This is an element worth paying extra for, especially as the price of 4500zł is still not a lot, as for the sound, craftsmanship, etc. But still the Phoebe III are my favorites. Like I said, the more expensive loudspeakers are better. And yet – the first love stays the longest with a man. And for me the first love were the Phoebe III.

Methodology of the test
The loudspeakers were initially placed on marble plates, later on anti-vibration platforms Acoustic Revive RST-38, and finally on thick wooden panels – every time to the side of my Harbeth M40.1, which I moved aside a little for this purpose. To counteract woofer movements in the Harbeth I short-circuited the wire terminals. The basis for the listening session was listening using my Soulution 710 amplifier. This is a solid-state amplifier, push-pull, with high output power. To have a broader insight in the sound I used also the Music-Hall a35.2 amplifier.
The comparisons were made using AB testing, with known A and B. The musical samples had the length of 2 min. The selection of music used for the test is mentioned in the beginning. The loudspeakers were facing quite wide apart. While listening from a greater distance than at my home, let’s say over 2m from the loudspeaker base – it is worth placing the loudspeakers with the axes crossing in front of the listener. The loudspeakers were placed about 1m from the back wall (counting from the back of the loudspeaker cabinet).
The room used for listening has an irregular shape and is connected with a kitchen annex and a hall. Together this is a room of about 30m2. The room has walls covered with shelves with books (behind the loudspeakers) and discs (to the left). Behind the listening place, on the wall, there are four modules Wave Wood from Vicoustic.

DESCRIPTION

The construction of the loudspeakers was already presented by their creator, but I will add some information to that.
The Hyperion IV are quite large floor standing loudspeakers with a 2.5-way setup in a bass-reflex cabinet. Three drivers placed on the front baffle are symmetrically placed around the tweeter, resembling a d’Appolito setup. However you need to know, that this is not a typical d’Appolito setting, as for this both mid-woofers would need to work in exactly the same frequency range, and the cross-over would need to be specifically designed. Here one of the speakers works as a mid-woofer, and the other one as a woofer, supporting the first one in the lower frequencies. Both drivers are identical – those are the Visaton W170S with coated paper diaphragms and carcasses made from pressed sheet metal. The top suspension is made from soft rubber and allows for quite significant stroke.
The tweeter is a very good metal dome SEAS H1212-06 27TBFC/G with a 27mm diameter and a chamber damping the pressure on the back of the diaphragm. In front of the tweeter there is a protective mesh. The diaphragm itself is made from an alloy of aluminum and magnesium, while the suspension is made from a polymer.
The cross-over is split into two PCBs – there are air and powder core coils and polypropylene SRC capacitors. The drivers are connected to it using a 2.5mm2 braid copper wire and soldered. The wire terminals are singular, with the sockets close together.
The cabinet is made from MDF and damped inside with felt. The veneer is pure wood, and very nicely applied. From the bottom there is a characteristic, black varnished plinth, to which we can screw brass spikes with a ball at the end. The loudspeakers are equipped with grilles.