OMNI-DIRECTIONAL SPEAKERS.
INTRODUCTION TO THE CONCEPT OF NATURALNESS
The nature of sounds generating, expanding in the environment and passively reaching our ears is omni-directional. When we listen to a live instrument or voice, the produced sound energy irradiates roundly, as a rock thrown into still waters creates a series of little waves extending in concentric circles. It goes without saying that the speaker system better able to approximate this physical reality is the omni-directional, which emits sound at 360°.
There are elements that arise upon listening which can efficiently summarize its distinctive qualities, and they can be synthesized in two points: the great feeling of freedom from the physicality of the speaker, corollary to the beautiful perception of liberty, and the unrivaled naturalness of emission. Omni-directional speakers do not force the listener to stand in a specific spot, but grant the autonomy to move about the room; in case more people are present in the same ambient, there will be no privileged listener, but all will be able to enjoy the same sound, not considering, of course, the variations linked to the emission of two different channels (essentially, the scene balance).
The second point is connected to the radiation characteristic: imagine a sound going everywhere creating a remarkable number of reflexions and, consequently, a score of small reinforces and random cancellings, although well distributed in time and in space. The final result will be the simulation of the gradual attenuation of high frequencies that happens in reality. Hence, the space/speaker symbiosis plays a fundamental role in the acoustic perception in these systems and, just as it happens in reality, the two entities become tightly intertwined with one other. It is important to specify that the person fond of these systems, but not used to them, may at first feel puzzled by a performance different from the usual.
Enraptured by the habit of a more “frontal” sound, he may find the speakers not efficient enough in the way they transmit the information; he will probably not forgive a lack of “shamelessness”. As time goes by, however, he will realize how this “invisible” singer wonderfully paves the way to a realistic listening experience, for the energy is evenly distributed in the environment and does not attack the listener with sound blades, but rather chaperones him towards airy scenarios. The music breathes with the ambient and merges with it better than with any other system. The result is the achievement of remarkable coherence and credibility. If on the one hand omni-directional emission may unbalance the relation between reflected and direct sound and the performance is influenced by the room acoustics, on the other it is true that directive speaker systems fail to offer a good sound stability at high frequencies: it is enough to move from the optimal spot even slightly to notice a change in the sound.
The advantages of a 360° diffusion, therefore, influence the tone balance, as low frequencies, being omni-directional, release a lot more energy in ambient with respect to the mids and highs, which are proportionally more directive. As a consequence, while an excess of pressure adds to the bass due to reflected waves, the same happens, in lesser amount, to the mids, and even less to the highs, with a result of a downward balance. Clearly, the omni-directional speaker features a more balanced performance.
BIRTH AND EVOLUTION OF THE VERO LOUDSPEAKERS
Carlo Crespan, designer of the Alkèmia Vero loudspeakers, cares to clarify the reasons that led him to this original creazion, not creditable to eccentricity or desire to astonish, but dictated by the strong belief that this is the best way to conceive well-sounding electroacoustics.
Davide Bresolin, a great professional in the electroacoustics sector with a thirty-year experience, currently Italian importer of Manger transducers, has had a fundamental role in the definition of the project. Thanks to his competence, it was possible to solve some key technical problems which arose during the creation/design of the Vero loudspeakers. A lot of water passed under the bridge from the creation of the prototype to the first version. The initial architecture was not exactly as it is now: the woofer was placed at the bottom, the reflex ducts were at the front, two overlapping plastic pipes. Later, it was considered to move the woofer at the top in order to make the reflex under it coaxial as well.
The material opted for was steel rather than plastic, selecting one duct instead of two. Such choice was adopted because also the reflex duct emits sound, and therefore should be kept coaxial to the drivers and not, as decided at first, at 90°. Moreover, the 8-mm steel pipe removed the coloring and imprecision of plastic. The project proceeded notwithstanding some difficulties: the professionals who worked carbon fiber were not used to drowning metal inside it to host the screws: at first, the owner even wanted to abandon the job because it was too complex. The dimensions too, the thickness of 4 millimeters, was a rather important problem, for they were used to working with tenths of mm.
Most part of the work was dedicated to solving the technical problems which arose along the way, together with the rationalization, choice of cables, condensors and reels, the numerous experiments executed on possible crosses of the crossover filter, done at all imaginable frequencies. A very important part of the research was done on the choice of internal materials, starting from glass wool and leading to custom synthetic foams, specialized for the various frequencies and modelled with 3D water saws. Also the addition of a tweeter at the top of the loudspeaker, which was at first not contemplated, is part of those decisions taken in progress. All the metallic parts are in stainless steel except the tweeter flange which is in aluminium, in order to reduce the weight. All bolts and screws are in stainless steel as well, and the black ones are darkened using the same procedure used for fire arms.
AMBIENT MEASUREMENT
For measuring, I used the "Arta" software (frequency and impulse response), “Limp” for the impedence module and argument and “Steps” for distorsions (second, third, fourth and fifth harmonic – THD). The latter have been detected at a level of about 90 dB. The hardware is a Superlux ECM 999 microphone, preamplified and A/D converted by The T Bone MicPlug USB; the calibration of the microphone/interface system was assigned to a PCE-SC41. Between to two sampling frequencies allowed by the MicPlug (44.1 and 48 Khz), I chose the latter. The software was managed by an E-Mu Creative Pre Tracker USB 2.0 audio interface.
Unfortunately, I do not have an anechoic chamber, nor the equipment necessary to measure in open air, crane included. For this reason, I have decided not to publish any graph with the frequency response. What I can say is that the range from 500 to 8000 Hz, the more stable one in the comparison between the measurement in an anechoic and in a reverberation chamber, resulted linear.
The measurement of distorsions led me down a rather complex path. Their detection in ambient suffers from the same limits as the frequency response, but I have decided to publish it nonetheless, so that the reader may have an idea of what can happen in real listening conditions. The true pulse of the situation was taken in “Near Field” measurments, carried out on every single driver in two different graphs: the first including the magnitude of the signal plus distortions and the second exclusively the distortions of second and third harmonics. These turned out all rather low as it can be noticed by the graphs. In particular, the Manger MSW has an excellent performance in the third harmonic which is always inferior to 0.02% in the 500 – 4000 Hz range. As usual, the fourth and fifth harmonics result even more contained.
The result of the impedence module and argument was very comforting; the former is basically always over 8 Ohms, therefore classifies the Alkèmia as a loudspeaker not difficult to pilot, representing a calm load for any amplifier. This datum, along with the fine sensibility, makes it manageable in normal house environments even by low power valve amplifiers. The result obtained with the TA2024 in dual amplification, in fact, was completely satisfying.
The first peak of impedence, of the value of over 40 ohms, is found at 17 – 18 Hz while the second, much smaller, is found at 60 Hz and has the value of exactly 20 ohms. The two peaks of impedence typical of the reflex charge, with the first higher than the second, are proof of a Fb (system resonance frequency) superior to the Fs (woofer resonance frequency in open air). This is found at about 35/40 Hz.
LISTENING TEST
With a pile of albums next to me I start the test using L.V. Beethoven's Sonata number 90 in E minor interpreted by Angela Hewitt, just to accustom my ears and brush up the system with a piece I really love. The volume is not loud, but it immediately allows me to detect one of Vero's main features, i.e. the splendid ability of rendering the natural timbres of instruments with a roundness which is constantly paired with brightness. I listen to the first two movements enraptured by the beauty of the music and by a soft interpretation, yet so efficient not to distort the power of those notes.
Immediatley afterwards, my attention shifts to a thought I have expressed many times before in this report: listening to an omni-directional speaker system compells us to reset our listening parameters. Perhaps if we are used to a directive sound, we could retrace in the Alkèmias a performance which is not frontal and direct. At a first listen, this will be mistakenly considered a lack of determination, but it will later manifest itself as a truly genuine space-time reconstruction of the message.
Following the favorable impressions regarding the timbre, I realize that its quality is so high that it becomes the “Leitmotiv” of my listening test. So, the amazing "Revelge, Trost Im Unglück e Der Schildwache Nachtlied" triptych from "Des Knaben Wunderhorn" by Mahler is convincing in the fullness of the different orchestral section, always well included in an intensely clear mix. The focus of detail never loses its efficiency from any listening point; I try standing up from the couch, moving towards and away from the line connecting the two speakers, but the precision with which every nuance is given is unaltered.
Gustav Mahler's 2nd Symphony “Resurrection”, interpreted by Simon Rattle and the Berliner Philharmoniker Orchestra allows me to integrate these feelings to a higher level of dynamic involvement. What materializes before me is an orchestral and vocal team, although far from the gigantism of the octave, called “the symphony of the thousand”. In the second I also find the song of “Des Antonius von Padua Fischpredigt”, present also in the “Boy's magic horn”. The sudden dynamic strikes catch the Vero's well reactive, when whipped they can react as thoroughbreds and the 37 watts in Class A of the integrated Shinai do not hold back in expressing all their vigour. The sound is free from any boxing effect: it expands airy in my living room.
In some passages a mid-low range with a little more weight would be more desirable; it is a trait I find more recognizable in modern genres such as jazz, plausibly typical of the nature of these loudspeakers, but that in no way penalizing altogether; it is enough to say that in certain occasions it tends to deprive a bit of bodiness and color in a rather limited range of frequencies.
The tenth CD of the sixth volume of the integral Brilliant “Bach Edition” contains masterpieces such as “Als Jesus Christus in der Nacht” BMW 1108 and “Christ, der du bist der helle Tag” BMW 1120, masterfully interpreted by Hans Fagius. The performance in the mid-high range is no surprise, as the deep and surrounding stage that magically takes us in the aisles of a great cathedral. Rather, the remarkable fullness of the deep low range emerges, present with immaculate efficiency on the pedal notes. The bass makes the reproduction supreme and is controlled the right amount not to initiate kneading effects, nor lack of articulation.
Carl Orff's Carmina Burana in the direction by Richard Hickox with the LSO challenge the Alkèmias even more in the dynamic jumps, which are remarkable here thanks to a high resolution recording (24 bits - 88 Khz); the sound levels are recognizable without hesitation, chiseled to perfection in a vast ambient. As the choir in "Fortuna Imperatrix Mundi - O Fortuna" enters, I receive a true electric shock by the performance of the rise times, my ears are hit by a sound lash full of well-timed energy. Additional distinctions rise among the different vocal registers and, I dare say, among every single voice, thanks mainly to the wonderful naturalness of the Manger MSW, a precious element in this system, which gives a very high detail level, never had before to the detriment of a superb liquidity and sweetness.
Just to state things clearly, we are light years away from a deteriorated type of care for detail which levers on a cutting and unnatural performance. The impedence module, practically always over 5 ohms, allows the two T Amps to perform effortlessly within their power limits. I have chosen a dual amplification setup with a NotSobad on the higher ways and a Trends TA 10.2 on the lower ones, achieving a result of absolute importance also in the field of the piloting capabilities. If I had not already been aware of the merits of this “Enfant terrible”, I would not have believed my ears before a timbrically perfect sound, featuring a great personality in spite of the low voltage. The rapid power amp Rotel RB 1070 did what it could, producing an honest sound, although distant from the magnificient transparent analyticality of Shinai and T Amp.
The occasion of the passage to modern genres is given to me by a high resolution file on my laptop's hard drive: Babatunde Olatunji in Love Drum Talk (24 bits - 96 Khz), a 1997 song with a lot of information. The percussions, lowered in an atmosphere of high level of density along with a well-done high register, challenge the Veros in the parameters of transient response and in the performance of details, delivered never pungent but meticolous. I take great plesasure in listening to the first and third track of the album: Sare Tete WA and Love Drum Talk: I repeat the listening several times, concentrating on the different details as well as the tracks as a whole.
The suddenness with which the multeplicity of information streams is unraveled is astonishing, along with the extremely low listening fatigue the Alkèmias generate. This asset allowed me to listen to them for six, seven hours straight without feeling tired at all; the plaesure of listening to them did not decrease. On the contrary, it increased. As it is well stated in the Manger web-site "No listening fatigue: listen indefinitely. This is the hallmark of a truly accurate loudspeaker": Whoever listens to a Manger speaker for a long time undertsands the meaning of these words.
Love Songs in a wonderful double album by Anne Sofie von Otter & Brad Mehldau. Von Otter, thanks to a voice which is naturally endowed of great flexibility and accompanied on piano by Brad Mehldau, is able to give a score of shuddering, heartfelt, interpretations, with an unmatchably all-involving lyricism. The two songs “It may not always be so” and “Dreams” exhibit a piercing musicality which almost brings me to tears at some point; the two Veros second that performance with great strictness, setting aside out-of-place desires of protagonism which would endanger the miracolous balance created by the two wonderful performers. Music must be respected and the Veros pose as interpreters, inflexible yet generous, sensual enough not to fall into fulsomeness.
I allow myself two listening sessions with the ineffable Franco Battiato: "Amore che vieni, amore che vai" from the Fleurs album of 1999 and "No Time No Space" from the more recent album Inneres Auge, published exactly ten years later. Battiato's voice is characterized by a slighly more coarse timbre and is essential to the point it becomes revealing of the passage between the low and the medium register. It does not have the beauty of Fabrizio De Andrè's voice, but it is just as rugged in hiding any imperfection in that critical area. The Alkèmias perform well in the slur of registers, nothing can be said except that the mid-lows result slightly underdosed. In the song “No time no space”, recorded as the entire album in a rather soothing way (i.e. with a quite boosted mid-low section) this feature results life-saving in cushioning certain imperfections.
He who thinks, perhaps misguided by my insistance on the features of exquisiteness of the timbre, that this is a “prappy” loudspeaker, born to reproduce little guitars, small voices and soft sounds, but that then gives up when it has to show some character, is completely wrong.
Frank Zappa's aggressive guitar in “Five-five-five” lets all of the Baltimore genius' visionary rage through; the explosive drum sections of the young Terry Bozzio in “Baby snakes” are repoduced with incisivity and show the eclecticism of a system at ease with any musical genre. The hats are never forcibly shiny; on the contrary, they result stable, moving about in every direction. The strong aftertaste left by these pages spurs me to continue down the road of more energetic genres: it is time for the great electric bassist Jaco Pastorius at the times of his collaboration with the Weather Report in Night Passage. The fretless bass is precise and well articulated, perfectly intelligible in every passage or rhytmic-harmonic hodgepodge: every hit is precise and quick.
You understand that an accurate timbric performance can benefit less “meditative” genres listening to Michael Brecker's tenor sax, which seems to enjoy the wonderful analyticity of the Manger in respecting every vocal or instrumental individuality, though in a complex context. The blowing of the instrument is puffed, with an eloquence that pleases the listener. The listening session continues entering Jazz with the album “I'm in the mood for love” by the Stefano Bollani Trio. I now want to distract myself relieving the emotional tensions of the previous program, so intense. Life is also made of light moments and the histrionic pianist has the right class to take the listener in a climate of elegant fun. Yet again, the Alkèmia Veros prove themselves as trustworthy friends who never let me down with superficial sounds. The performance is one of class; I note a pleasant harmonic richness in the folds of the musical fabric, along with an amazing liquidity and total absense of grain.
I finish the test electrified by the sparkle of the sound of Chick Corea in the full-bodied collection “Five trios”, unsure on the tracks to play. In the end I choose the jubilation of happiness and swing following the meditative Crepuscule with Nellie. Milestones and Dusk in Sandi give the last proof of the verve of these omni-directional speakers, which effortlessly recreate the right mix of timing, naturalness of emission and beauty of color, all elements which will be hard to forget for whoever will encounter these seductive systems.
CONCLUSIONS
Within the complex nebula of loudspeaker systems, the Alkèmia Veros offer themselves as eminently transparent protagonists, respecting a musicality able to nobilitate any program.
Transparent as their name suggests (“Vero” in the Venetian dialect means “glass”), they return a mix of colors and timbers that does not live of deployments, but of integrations. The also vigorous contrasts are always proposed with great coherence; they do not attack the sense of hearing, but originate and expand in the surrounding environment with the utmost naturalness. They are never tiring, not even after long listening sessions.
The performance of the Manger MSW is astonishing; it's very efficient in the reasearch of sounds and atmospheres that seem to materialize in the air out of nowhere. The use in omni-directional configuration does nothing but highlight these features, bringing them to their acme.
The ability to show the detail is on levels of excellence. A difference I noted from equally performing loudspeakers is the absolut lack of strenuosity in the approach to the particulars; for this reason, they always feature a surprising naturalness along with a disarming “ease” of emission, result of the long studies carried out by Manger on the real modalities of diffusion of sound waves and well supported also by the two other loudspeakers.
There is no need for many watts, nor enormous amplifiers to pilot them in a typical medium-sized domestic environment; rather, we suggest the choice of one which is able to enrich their superb class without mortifying the truly remarkable harmonic richness. Placing them in the ambient is not problematic. Great freedom is allowed in setting the loudspeakers, no millimetric toe-in will be necesary to balance scene and detail. For what concerns the acoustic treatment of the listening room, we should consider that omni-directional speakers have reflexions as an integral part of the reconstruction, therefore lessening them excessively means depriving the listening experience of an important part.
It goes without saying that an acoustic treatment aimed at rendering the room reflexion free should be done with a light hand, considering that a certain acoustic liveliness is necessary in order for the Veros to perform at their best.
Alfredo Di Pietro