CHARIO ACADEMY S SOVRAN
ACADEMY S SOVRAN
Control and power
The first three-way loudspeaker system able to control energy diffusion at low frequencies, using Chario Loudspeakers prioprietary Doublet Radiation principle. A decisive step ahead, laying the theoretical foundations for a different approach to sound issues in small environments.
Natural wood changes shape depending on ambient temperature and relative humidity. In other words, it adapts to climate conditions, generating outright tensions inside its fibres, which modify the macroscopic layout. This fact is well-known to master cabinet-makers, who actually adapt techniques when assembling the various parts of any prized solid wood cabinet.
Firstly, the right board has to be chosen and cut using precise criteria to avoid creating isolated and incompatible sections.
Secondly, the right storage area and drying process are defined for the rough wood. Thirdly and lastly, the sections are assembled in a precise order, to allow the moisture-absorbing capacity of each element to develop over time, settling to achieve soundness, not breakage. That’s why the CNC machines only cut and mill. The rest is time-honoured craftsmanship…
As in Serendipity, the Sovran infrastructure is intended to stiffen the unit thus damping the mechanical vibrations and confining them inside the cabinet. There is another feature, however, that illustrates the complete extent of this original approach, which may seem complex in its realization, but is actually user-friendly in its basic principles. Just remember that the source with the most impact on any loudspeaker cabinet is the subwoofer. Vibration transmitted in this way to the structure has two negative effects: (1) the cabinet acts as an additional uncontrolled radiator; (2) the other speakers oscillate around their point of resting, modulating emission and reducing sound detail perception. The solution is simple and elegant: physically separate the subwoofer, which is why the cabinet comprises two vertical units, connected by four proprietary form and geometry puffers, extensively uncoupling the two cabinet masses. The image on the left shows the tensor surfaces, reflex duct and the structure that houses the two 200 mm subwoofers in the proprietary NRS isobaric configuration. The demarcation line between the upper and lower sections can be seen at the base of the tweeter bore.
Five degrees vertical tilting
The Acoustic Doublet proprietary theory that was developed for the Academy Sovran project allows even small-scale systems to use speaker/room interferences that will give listeners wave-fronts containing spatial information. This type of information is linked to the size of the source and length of wave emitted and it’s unlikely to be conveyed to the listener by bookshelf loudspeakers, since a physical distance of at least 1m is needed between sources. This is one of several reasons why Sovran adopts Reversed Woofer/Tweeter Alignment, which keeps the woofer as far as possible from the subwoofer and at the same time provides the best angle for modelling the energy response around the second crossover region.
Academy Sovran is built, as all the Chario Speakers, completely in Italy. Available finishing are Solid Walnut and Solid Cherry. All the woods are treated in a particular way to guarantee at least 6 month of drying process.
Positioning of the speaker in an acoustically treated and balanced is strongly recommended. The size of the ideal listening environment should not be less than 16 square meters and not more than 60 square meters.The minimum amplification suggested to fully exploit the characteristics of the diffuser is 30 W / 4 Ω.
"Academy S" Series Overview
Music and science are often thought to be two sides of the same coin and as such cannot be seen simultaneously. This apparent dichotomy encourages audio system designers to address problems from two quite opposing standpoints. Some trust in their emotions and some rely on their PC. Pure and simple. But looking deeper at the scientific side of the coin, this false impediment will disappear and the mind corrects the confusion of the eyes. This is when music and science blend together.
So there are basically two ways to offer the listener the pleasure of the musical experience: To be a maker of musical instruments or to be an audio system designer.Let’s think about how a sound takes shape. We already know that air particles must be made to oscillate back and forth to propagate acoustic energy. Good examples of vibrating bodies are a stretched drum skin, the prongs of a tuning fork, plucked strings… But there are also musical sources that in appearance aren’t out right vibrating bodies, for instance a trumpet or a clarinet, which physically actually rely on the mass oscillation of a volume of air.
In any case, the condition to be met is that air molecules must be forced to vibrate in contact with any surface moving quickly. The air vibration should last long enough for our system of perception to translate the neurosensorial stimulus into a hearing sensation, otherwise we won’t be aware of any sound.
Now, what is the aim of a skilled musical instrument maker? Simple: He/she has to discover the secret that ensures the instrument continues to vibrate as long as possible. Now this is what we usually call resonance, so we can say that the main scope of a vibrating body used to make sounds that please the ear is to release gradually the energy it received from the instant impact of a bow, a plectrum, a drumstick, a reed… The more harmonious (in the usual meaning of this word) the resonance is, the greater the pleasure it offers.
However, to understand this in full, we should now take a closer look at how a loudspeaker works. To assert the validity of the original statement it would be natural to consider a musical instrument/loudspeaker analogy, but that’s not such a good idea… Both loudspeakers and musical instruments feature a rigid structure that contains a volume of air acting as an acoustic load in the speaker and a resonator in the instruments. If they worked in a similar way, neither would offer any musical quality since the air volume acts differently in each. Actually, to reproduce the complex structure of the energy released by a violin, it must be passed through the electric signal generated by microphones via an audio system that has no resonance at all, otherwise sounds not present in the recording will be heard. All physical systems tend to retain acquired energy through inertia and a loudspeaker is no exception, hence the speaker engineer could be seen as the counterpart of the musical-instrument maker.
Consequently, a speaker designer becomes the master craftsman’s alter ego. Both make devices to generate sound but while the engineer is the sworn enemy of resonance, the craftsman is its loyal ally… To assert the validity of the original statement it would be natural to consider a musical instrument/loudspeaker analogy, but that’s not such a good idea…
Both loudspeakers and musical instruments feature a rigid structure that contains a volume of air acting as an acoustic load in the speaker and a resonator in the instruments. If they worked in a similar way, neither would offer any musical quality since the air volume acts differently in each. Actually, to reproduce the complex structure of the energy released by a violin, it must be passed through the electric signal generated by microphones via an audio system that has no resonance at all, otherwise sounds not present in the recording will be heard.
Our design philosophy and the technology we have developed since 1975 can be summed up like this:
- Psychoacoustic research based on state-of-the-art hearing models
- Time field measurement using binaural techniques
- Simulation with FEM transducer and cabinet synthesis
- Study and application of microphone arrays
- Subjective statistical analysis
- Use of cutting-edge technology materials
The rationale behind the Academy ‘S’ Series is really underpinned by just a few concepts. The idea was to use a two-stage strategy to make the listener feeling they were “right there”:
1. Pulling out existing ambience information from standard recordings, presenting pressure variations on the listener’s ears in a new, unprecedented way.
2. Cutting down the negative influence of initial listening ambience bounce.
The aim is, of course, to achieve credible surround audio… but the laws of physics can’t be broken. Some limitation are only natural in the recording/reproduction/perception audio chain, and will resist despite our best efforts to replicate in our own surroundings an acoustic event originating in a large dedicated venue. An accurate audio recording contains large amounts of environmental information associated to the reverberated field. Intense energy content bounce, similar to direct field, channel recording venue size information and are closely linked to source localization sensations. The ambience, field depth and “air” amongst instruments information (basically responsible for the holographic effect), however, are contained and carried by the long-term energy decay field, whose fate is to be lost in the room’s background noise. Many listeners think they are unable to perceive this type of signal, whereas it is really very easy to realize they are “absent”, because the associated sensation is loss of virtual stage depth, as if the entire orchestra were tanding in one horizontal line. This form of source geometric distortion is especially noticeable when listening to musical programmes coded with lossy compression algorithms, or programmes that have not been compressed but reproduced using an audio chain with one or more low resolution links. When these weak signals have been recovered, how will they be used?
We could try to “surround” the listening position with several speakers, although this isn’t a realistic proposition as the hearing system would immediately pick up on the low coherence of the virtual images which, in this case, would be the reason for distortion of the geometrical representation. Moreover, if we were to force the right and left front sources also to emit ambience signals, our brain would be confused by the presence of contradictory sources to associate to just one inducer for both the direct and reverberated camps. So information on the binaural plane has to “disperse” in a controlled manner to reconstitute the original situation with acceptable approximation, without compromising localization of the sound front.
The Academy Serendipity project is based on the theory that an upturned vertical array, with differentiated alignment gains and delays, acts as a distributed source (antithesis of the pulsating sphere) that can provide the listener’s ears with counterlateral signals able to widen the sound perspective to the limits of correct localization, turning to good use the adverse condition of interaural crosstalk typical of stereo systems with front speakers (Blumlein).
On the subject, a short digression on the three Perception Hypotheses developed by Chario in its Psychoacoustics Laboratory at the head offices in Merate (LC).
First Perception Hypothesis
Floor bounce control versus timbre colouration. Acoustic measurement of loudspeaker systems is normally performed in suitable bounce-free chambers. This is a fundamental condition for testing the exact functioning of the entire system without it depending on the place where the trials are performed. The geometry of a domestic setting, however, shapes speaker response and consequently modifies the listening experience completely. Since there are endless speaker/room/furniture combinations, a computer-aided simulation can only outline a general performance that is useful for assessing reproduction balance but insufficient for describing the hearing sensation. Current psychoacoustic models are still incomplete and provide reliable results only when the acoustic event is fully controlled. Now, because any free-standing “tower” system has a fixed driver-to-floor distance, once the listening distance has been established, distortion caused by initial floor bounce can be calculated. So if there are no more bouncing surfaces at less than a metre, the first energy bouncing from the floor can be controlled by the appropriate combination of crossover filter and vertical driver array. This type of interference is especially annoying because the listener is aware of both the loss and the excess of energy within a frequency band that is an octave wide, which generally resembles the central octave of a piano, in other words the set of musical notes most recurrent in western compositions. The musical octave relationship between the dip and the peak implies a dramatic timbre alteration in the complex tone generated by the sound source because in a worst-case scenario, floor bounce adds an incremental difference of almost 10 dB between the fundamental and the second harmonic.
Second Perception Hypothesis
WMT™ is a Chario Loudspeakers exclusive feature for control of energy from at least three drivers: Woofer, Midrange and Tweeter. The three don’t overlap in the standard way that combines three distinct frequencies; instead, the almost complete woofertweeter response is integrated by the midrange working in a single octave range. This proprietary crossover filter enables gradual, uniform reduction of off-axis system response, thus ensuring homogeneous distribution of energy in the room, benefitting the first bounce field. The WMT™ configuration also enables control of the energy directed upwards and downwards, with a substantial reduction of initial bounce. The psychoacoustic effect achieved for the listener by this exclusive operating principle translates into greater detail and transparency at mid frequencies without having to raise them to unnatural levels that ruin both timbre precision and stage depth.
Third Perception Hypothesis
Musical instruments can produce sound levels of 120 dB SPL, although this huge amount of energy is not available for ordinary home listening for two key reasons:
1. Small rooms quickly reach saturation point if levels are increased
2. The electroacoustic technology currently available doesn’t allow direct emission speakers to release very high pressure.
It is therefore reasonable to take 110 dB SPL as a feasible maximum for short fortissimo (fff) sections. Moreover, however quiet a domestic environment may be during the day, there is always at least 45-50 dB SPL background noise, so the actual signal dynamic range is no greater than 60 dB (the difference between 110 and 50). It is no coincidence that the same figure of 60 dB defines reverberation features for any closed space and if this is the recording venue, our hearing system associates the sensation of space to any signal captured by microphones. These extremely weak signals have to be reproduced correctly to recreate an ambience effect (the illusion of being seated in the original recording venue) in the listening point. Human hearing works in a very complex way but there’s no doubt that it adjusts its sensitivity response to sound intensity and frequency content.
If the system’s frequency response is shaped to the loudness level curve envelope for 45 Phon, it is near to the goal of reproducing ambience information aligned with human ear sensitivity displayed at 40-50 dB SPL (beyond which it is lost in typical domestic background noise) emission levels. The particularity of this original solution is that it is very effective in offsetting the inherent paradox of the loudspeaker system reproduction principle. It is established that during a concert in a closed venue, human hearing is reached by two distinct sound fields: one is direct and comes to the source along the line-of-sight; the other is reverberated and comes from all the surfaces of the enclosed space. The reverberated field not only suffers delays because of multiple bounce, but also has no single arrival direction – statistically speaking – as it comes from all directions except the one already occupied by the direct field. So it’s obvious that when listening at home, the memory has no way of comparing the phenomenon, as the direct field and the reverberated field come from the same point. This new situation confuses the auditory system and in an attempt to make sense of this contradiction, activates a process of “directional listening”, focusing too hard on the sources. At this point, it is easy to see that if the ambience information is returned on a linear curve, the brain pays too much attention to the mid frequencies, with consequent collapse of the stereo front “between” the speakers.
ACADEMY S SOVRAN
3-way vented, NRS down-firing floorstander
- Low frequency load: Vented NRS Exponentional Hourglass
- Vent geometry: Bi-Dimensional Hyper-Exponential Hourglass Type
- Configuration: 3-way Reversed Vertical Alignement Free-Standing
- Drivers: 1 Tweeter 32 mm SILVERSOFT™ dome NeFeB motor
- 1 Woofer 170 mm ROHACELL® Full-Apex™ Poly-Ring NeFeB motor
- Sensitivity: 90 dB SPL normalized to 1 m / 2.83 Vrms / de-correlated L/R pink noise within ITU-R BS 1116-1 compliant listening room
- Low frequency cut off: 35 Hz @ -3 dB referred to C4 WETS
- Doublet crossover: 100 Hz
- Mid-High crossover: 1180 Hz / LKR4 Derived (Δf=45°)
- Rated impedance: Modulus 4 Ω (min 3.0) Argument ±36°
- Size: 1220 x 240 x 440 mm (H x W x D)
- Weight: 47 kg
- Cabinet: Solid walnut or solid cherry and hdf. The structure comprises two cabinets: the lower contains two subwoofers; the upper contains one mid-woofer, and one tweeter. The two wood cases are separated by four cylindrical proprietary-engineered elastometric puffers acting as vibration decouplers to dissipate mechanical energy by orthogonal elongation.
- Speakers orientation: Speakers should be titled inward facing the listener
- Listening distance: Optimum speaker-listener distance > 3.0 m
- Listening layout: A carpeted floor in front of the speakers is recommended
- Side and back walls: Should be at least 1m away from the speaker front baffle
- Suggested amplifier normal amping: 180W / 4 Ω Average Power
Run the cable from the power amplifier to the lower terminals of the subwoofer binding post, then connect upper terminals to the mid-high unit binding post by means of the short cable provided with the speakers
- Suggested amplifier bi-amping: 120 W / 4 Ω Average Power
Run the cable from the power amplifier to the lower terminals of the subwoofer binding post leaving upper ones idle. Repeat to connect the power amplifier to the mid-high unit binding post (two terminals only)