The Symphonia speaker is our new pride , the result of a 5 year old R&D journey, in horn speaker engineering.
High frequency reproduction
The HF transducer, is a customized highest quality true Al foil ribbon, made from RAAL company. This is loaded with a specially designed and unique shaped horn, to dramatically alter the parameters and performance of the tweeter.
The unique shaped tweeter horn, is a Zero Diffraction horn, with a 360 degree continuous flare, eliminating all possible diffraction in vertical and horizontal axis, delivering perfect performance in frequency and time domain, with unmatched transient and distortion figures, by any other HF transducer technology used. The horn body is made from solid wood.
The midrange horn is made from solid wood, it’s unique flare is designed to eliminate all possible diffractions, which all other horns suffer from, and are part of their sound character. We completely eliminate diffraction coloration, which smears transients, with our 360 degree bullet-shaped solid-wood horns. The driver used is large format (4inch diaphragm) titanium driver, with a massive magnetic system(11kg magnet weight).
The midrange acoustic level can be altered via a multitap transformer, for tuning the speaker according to each room’s acoustics.
We believe that bass delivered from horn loaded drivers are unmatched in performance, as long as the horn in properly designed. Folded horns suffer from three major factors.
-First is their usually shorter length for the bandwidth used. Shorter horns and small mouth-area bass-horns, have large frequency response ripples, and strong coloration. -Second, the horn is usually not properly folded, as the horn flare is formed by conical sections of wooden sheets, with a sharp angles and many parallel surfaces, trying to resemble something like a horn flare. -Horns and bass horns in particular, submit their internal walls to extreme pressures. Plain sheets of wood are just not appropriate for this task.
The Bass horn used, is a 3.3m long horn with very large mouth area for the bandwidth used, providing excellent performance in bass extension and weight, with the lowest coloration than any other folded horn.
The horn flare ,is a true tractrix flare , formed by stacked sheets of plywood, carved to formed a true 3.3m long tractrix horn, properly folded without any internal sharp angles and geometrical deviation from a the tracrtix flare. The stacked plywood construction, provides 10 times the stiffness (along the horn axis), compared to conical horns formed by sheets of wood, also constructed with much reduced weight/stiffness ratio, providing minimum energy storage.
The external crossover, consists of three constant group delay filters. A constant group delay filter, is our own proprietary design, which alters the attenuation slopes of the driver filters, to shape the phase(and doing so the GD)in such a way ,as to provide maximum GD linearity. Using this specific filter technology to the physically time aligned horns, the Symphonia speaker present time domain performance which is near perfect, and a frequency response with a maximum deviation of +-0.5db (250Hz-20KHz).
Story of the Symphonia speaker
What lead to the idea to build a horn speaker like the Symphonia?
Years ago as a young audio enthusiast, I was fascinated with horn speaker technology, and quickly recognised the innate potential in their design. After a lot of reading and research of the physics involved I began to develop an appreciation of the prior art, while at the same time noticing how almost all contemporary horn designs had fundamental flaws that undermine the advantages and introduce additional problems. I wanted to take the concepts from the early horn era and push them further, taking advantage of the technology of today in terms of computing, simulation, CAD-CAM and manufacturing advancements, and use it to achieve something that could be thought of as a step forward from the better designs of the past, instead of a step backwards, which is unfortunately often the case.
The Symphonia began as a personal project, long before the establishment of Aries Cerat in 2010. Shortly after we started the company, we initiated two parallel development platforms, the Contendo and the Symphonia. This gave us two horn speaker projects, allowing us to exchange concepts and innovations between them. The horn-loaded ribbon tweeter, for example, with its innovative 360deg flare to eliminate diffraction was initially developed for the Contendo, but was utilized in the final design of the Symphonia. Similarly, the solid wood midrange horn with its special bullet shaped enclosure - again, to eliminate diffraction - was developed for the Symphonia and then used in the new Contendo.
So, you can say that the Symphonia was not an isolated project, but a project that grew along with the company and adopted many breakthroughs from other speaker projects that were also in progress. Our proprietary variable slope filters with constant delay characteristics, for example, were in development for many years, and although our smaller speaker got to use them first, the development platform was the Symphonia.
Part of the reason for the Symphonia’s extended development was that a lot of work and effort went into eliminating problems that accompany horn physics, which if not addressed thoroughly produce mediocre results. When overlooked, these problems manifest themselves as nasty sonic traits that many - wrongfully - attribute to horns in general. In my opinion, a poorly designed horn will always sound worse than a poorly designed conventional speaker. If the design of a horn speaker is compromised from the beginning, either from budget limitations, technical resource limitations, or simply lack of proper understanding of the physics involved, horns are better avoided and conventional dynamic driver speakers should be pursued instead. However, I still regard horns as the ultimate electro-acoustic transducer, but only when the specific aspects of horn design are respected and implemented correctly. This is what we tried to do with the Symphonia, and we strongly believe we’ve succeeded.
What are the major differences between historical and current design in horn speakers?
I don’t think it’s right to put all horn designs in one basket. Many of the old designs are landmarks of audio reproduction and still relevant in showing the new guys how it’s done. Of course, some of the older designs were very much flawed and extremely colored by today’s standards, so one must be careful and evaluate each design on its own merits.
I find the problems of many contemporary horn designs stem from two main sources:
Firstly, the lifestyle-oriented design of most horn speakers. Unfortunately, many design choices prioritize aesthetics over function. That’s not to say physical beauty is irrelevant, but in-and-of-itself can never make up for compromises that negatively impact reproduction.
Secondly, a basic lack of knowledge of horn physics. Past speaker engineers had different priorities, and although they lacked access to modern CAD-CAM systems, simulation programs etc, they arrived at designs that respected the basic and advanced aspects of horns and always managed to take a step forward. While acknowledging everyone will approach the inherent problems of horn design with their own ideas, I find it difficult to understand some contemporary designs that clearly ignore the basic principles underlying all horns, despite the historical knowledge and modern technology available.
What does it take to achieve a full range, full-spectrum horn sound?
To answer this, we have to differentiate a true horn speaker design from speakers than use waveguides or other directivity control apparatuses, hybrid designs etc. Unfortunately, categorization of a speaker as a “horn” often blurs the definition creating confusion in the audio world. Horn loading is something very specific in terms of physics, implementation and end result.
A horn is an acoustic impedance transformer. Using an analogy in mechanical terms, imagine you have a 1hp servo motor coupled to a feather-like axial load. This is analogous to a direct radiating driver. Energy transfer of such a system is very poor, mechanical energy is wasted and efficiency is very low. On the opposite extreme, imagine you have a 0.1hp servo motor coupled to a 1m diameter steel disk. Again, we have extremely low energy transfer, but for opposite reasons. This is usually the case with electrostats and planars.
For our purposes of maximizing energy transfer in the conversion of electromagnetic energy to acoustic energy, ideally the motor “impedance” must be equal to the load “impedance”. Again, using a mechanical analogy, a horn is simply the acoustical equivalent of a gearbox, matching the impedance of the load to the output impedance of the motor.
However, like most things audio, there’s no free lunch. Horns are bandwidth limited - you sacrifice bandwidth for efficiency. If we’re talking about reproducing the full audio spectrum, this inevitably means separate, specially designed horns intended for specific bandwidths. We’ve found that in theory, as well as from real world data we’ve collated, horns perform better when handling a maximum of 1.5 - 2.5 octaves, even if the drivers loaded within the horns can handle much wider bandwidth.
To achieve a full spectrum horn sound, you have to respect the horn physics involved. For example, let’s consider just the first two octaves from 27.5Hz to 110Hz. To get usable extension with bass horns, you need a certain length and mouth area for a given cutoff. Horn cut-off frequency is always a function of size. The goal for a compact, delicately proportioned speaker suddenly goes out of the window. It’s very difficult to design properly within those constrains.
The reality is you can’t bend the laws of physics in an attempt to get around cut-off frequency, hence why a lot of hybrid and semi-active designs exist in the market. We understand the appeal, but we feel the inherent trade-offs involved ultimately inhibit the design and reduce performance. In order to achieve a full-spectrum design over the entire audio spectrum with limited bandwidth horns, the only solution in pursuing a line of least compromise is multiple dedicated drivers and horns, and as an inevitable consequence, an increase in cost, size, weight and complexity.
How does the Symphonia differ from the other contemporary horns?
For the Symphonia project, we decided to address many of the underlying issues associated with horn theory that in practice are often severely compromised in lesser designs. We attempted to find the very best solution to each problem, with as little compromise as possible, and combine them into a single entity. We took no shortcuts in our efforts to realize each proof of concept, whether relating to the diffraction-less horn enclosure, specialized group delay filters, bass horn design or the tweeter design. We wanted the Symphonia to be a platform to show how a horn should sound when horn physics are properly understood and implemented without compromise, eventually materializing in a design that’s small enough to go through doors - although only when disassembled!
What approach does the Symphonia use for low-frequency reproduction?
Our approach on bass loading is pretty straight forward, even though the technical solutions we employed were not. We needed at least 3m of horn length and 3300cm2 of effective mouth area. Usually in most contemporary designs, the default is of the use of shorter horns, resulting in limited bandwidth and the presence of ripples throughout the pass-band. Trying to geometrically approach a conical horn using commonly employed methods of folding horns - that is, conical sections of wood sheet to form a successive conical section - was problematic from both a practical and performance perspective.
Instead, we chose to employ a tractrix flare profile, strictly avoiding any sharp corners, deviation from actual theoretical geometry and with no abrupt curvature changes. This is a much greater challenge from an engineering perspective. Fortunately, we have a five-axis CNC router with a 5m3 work envelope that gave us the capability to design and manufacture a true tractrix horn from twenty-five vertically stacked sheets of plywood that satisfied all the above criteria. Another major advantage conferred by the stacked plywood structure was that is has the requisite mechanical rigidity to withstand the high acoustic pressure present inside the mouth of the horn, especially at these frequencies.
What type of horn does the Symphonia use for the midrange?
One of the things we wanted to overcome was the problem of diffraction that almost every horn suffers from. Diffraction is one of the major sources of so-called “horn sound”, whereas a true horn properly designed and implemented should not and will not have an identifiable sound of its own. We decided to employ a round tractrix horn, modified with a specially-designed 360-degree diffraction-less flare. By using a bullet-shaped enclosure, we were able to completely eliminate colouration due to diffraction, and avoid the smearing of transient information that usually occurs.
We wanted the horn to have a cut-off at least 0.5 octave lower than the crossover frequency, so we designed it to have a cut-off at 330Hz. The horn and bullet-shaped enclosure is CNC machined from solid plywood block, with a thickness of up to 15cm. The poplar plywood used was preferred to other types of plywood, as this had twice the strength-to-weight ratio of other types of plywood. Energy storage is thus halved.
The driver used is a large format titanium driver with a 4-inch diaphragm, coupled to a massive magnetic system weighing 11kg. The midrange acoustic level can be altered via a multi-tap transformer, allowing the Symphonia to be better integrated according to each room’s individual acoustics.
How is the Raal tweeter utilized, and how does it perform at higher sound pressure levels?
The development of the Symphonia’s tweeter was spread throughout a three-year long journey. I was always mesmerized by the sound of a true ribbon, especially Raal’s designs, but usually direct radiating ribbons lack the punch and dynamics of a high-frequency compression driver. On the other hand, no compression driver could ever deliver the detail, accuracy and bandwidth of a true ribbon transducer. So we began research on whether it was possible to combine the two approaches to get the best of both worlds.
A normal ribbon is not designed to operate in high acoustic pressures typically present at the throat of a horn. It soon became clear a special ribbon would need to be designed. After modification and experimentation on the Raal tweeter, we found the end result to more than meet our expectations. However, horn loading the ribbon still presented challenges. We were reluctant to use conventional solutions such as waveguides or directivity control apparatuses that would be inadequate for the task, so we endeavored to find a new approach.
This lead us to design a horn flare to specifically load the ribbon as a true horn. Nevertheless, the line source emission characteristic of the ribbon made this extremely difficult. Diffraction is secondary sound emission, and takes place in geometric anomalies, transitions of geometry and changes in curvature. It’s very much audible and almost impossible to eliminate. In horns, diffraction is present at the horn termination for round horns. In rectangular horns the problem is much worse.
The solution was the implementation of our diffraction-less 360-degree horn technology. We designed the horn flare to expand to 360 degrees, while maintaining the flare curve’s second derivative constant, keeping the curvature slope constant. Precise measurements were made of each iteration in an attempt to match the simulation and theory to its real-world acoustic performance. We found variations of just 0.2mm to have detrimental effects on the horn’s performance. Manufacturing them to specs from wood was also challenge. In the end, a total of fifteen different flares were designed, built, measured and eventually discarded before we settled on the final design that performed as we wanted.
The ribbon-horn combination response is shaped to measure flat from 3KHz upwards. It delivers detail and resolution associated with only the very best ribbons, with the solid punch and dynamics of the very best high frequency compression drivers. Distortion characteristics at 114db are lower that those of the best dome tweeters at 95db. What’s more, the diffraction-less nature of the horn enclosure gives the tweeter unmatched time domain performance.
What’s needed to show the real potential of a horn speaker?
When properly designed and implemented, horns can be a true magnifying glass of the components that precede them. That means they’re not very forgiving of lesser amplifiers and sources. Ambience, detail retrieval, micro dynamics and timbre are all encoded within and below the level of an instrument’s fundamental notes, and because of a horn’s high sensitivity and resolution even at normal listening levels, the first few milliwatts of power matter.
Even for peak signals, a horn will often be drawing only a few watts of power, so the need for signal integrity from the amplifier at low power becomes exponentially more significant. This is where solid-state and most push-pull designs fail - the first few milliwatts. Of course, heavy and inefficient speakers mask the artifacts inherent in those first few watts, and are usually coupled with amplifiers in which their low power behavior is therefore not revealed to be severely compromised in ways a properly designed and implemented horn will.
How would you compare the Symphonia with other horn manufacturers like Avantgarde Acoustics or Cessaro for example?
There are many ways to design a horn speaker. But that’s not the same as saying all horn designs understand and respect the laws of physics. There are some very specific concepts that need to be addressed and solutions implemented if one is to avoid a compromised result. In conceiving the Symphonia we looked into the myriad of problems a horn design entails, and attempted to address each one with the least compromise possible. Four of the major problems associated with horn design include but are not limited to:
1) Too wide a bandwidth for a specific horn/Improper flare for the bandwidth
Many designs usually get this very wrong. Any horn will have a specific bandwidth within which it can work optimally. Usually, designers “stretch” the horn’s pass-band in an attempt to avoid having to use more horns/drivers for a particular design, making for a design that’s more compact, aesthetically appealing, is easier to manufacture, less complex, etc. The problem associated with a horn operating in the wrong bandwidth is that it produces high-order distortions as well as nonlinear distortions.
Horns are very sensitive to their termination geometry - i.e., the geometry that follows after the flare ends. Discontinuities in the geometry and even changes in curvature can generate a secondary emission. This delayed emission returns inward to the horn throat and driver, as well as radiating outward towards the listener. This is called horn diffraction and is very, very audible. Horns installed on baffles present high levels of diffraction, while rectangular horns present high-order distortions and many diffractive surfaces. Diffraction is the major factor in creating the “honking” sound associated with most horns.
We believe tractrix flares have the best measurable and subjective performance. We only use round tractrix horns, modified to our 360-degree flare to eliminate diffraction. Both the tweeter and midrange enclosures use this technology. Unfortunately, these bullet shaped 360-degree horn flares are a complete nightmare to design and build, and would be impossible to manufacture without extensive use of our CNC workstations. However, in my opinion, it’s completely worth the time and energy, as it solves the ongoing problem that seems to exist in other designs.
2) Improper driver used
Not all transducers are suited for horn loading. Many times improper drivers misbehave in nonlinear and unpredictable ways when loaded with a horn, irrespective of the horn’s design. Appropriate drivers are usually expensive and hard to acquire. The most important aspect is in finding the best driver for the intended bandwidth. However, this is never straightforward, and many parameters must be looked into, not just the more obvious ones found in textbooks.
3) Inferior horn construction/material
A horn presents sound pressure levels many times greater than the pressure present in a conventional speaker. A plastic horn, however thick it may be, will ring and be a secondary source of resonance, colouring the sound. A thin plastic one, no matter how aesthetically pleasing, is a complete nightmare in this regard.
In designing the Symphonia midrange horn, we conducted extensive objective and subjective testing, alternating between a 2.5cm thick composite 330Hz tractrix horn and an identical horn built from stacked poplar plywood with 15cm thick walls. Both our objective analysis using burst decay and listening tests revealed that the plywood horn was vastly superior, even though the composite horn at 2.5cm is still much thicker than the market’s standard.
Of course you can’t make 15cm thick plywood from injection moulding, so they’re constructed in a labour intensive process using CNC machining to extremely high tolerances. Many of our ideas and concepts could only be materialized after the acquiring of highly specialized equipment, such as our 5-axis work station with the highest Z-axis envelope available, making it possible to carve anything from our material of preference. Of course, this ends up being much more costly and time-consuming to manufacture, but presents a solution with the least possible compromise.
4) Improper time alignment/filtering
Flush placement of the front of the horns so that they’re physically aligned might result in an aesthetically pleasing speaker, but the result is an incoherent sound - one of the many sonic maladies horns are accused of. Improper filtering of the horns is also a source for coloration. Crossover design and physical alignment must address all issues that derive from both the physical position of the horns as well as the actual acoustic filtering inherent in a horn-loaded driver. Solving these issues must be done in a way that avoids treating them as isolated variables - they must be treated as a singular one. This is rarely addressed.
Time alignment is not just physically aligning the driver’s diaphragms, as is very often claimed for speakers that call themselves “time aligned”. The acoustic centre of the driver is not often located at the centre of the physical diaphragm itself, instead it maybe be offset forward or behind the centre of the diaphragm and is often frequency dependant. During development, we time-align the drivers using customised measuring rigs that excite the filter-driver-horn as a complete entity, and only after analysing the transient response of each filter-driver-horn system do we physically align the horns relative to one another to be truly time-aligned in the acoustic domain. Visually aligning the driver’s diaphragms is of no use from an acoustic perspective.
The external crossover designed for the Symphonia consists of three constant group delay filters. The constant group delay filter is our own proprietary design. The frequency response of the filters at the stopband does not follow standard profiles used in speaker filters, neither passive nor active. Instead, the filter’s attenuation slopes are varied and shaped in a way that the phase derivative - the group delay - is kept both constant and linear. Using this specific filter technology in addition to the true time alignment of the drivers, the Symphonia is able to produce time domain performance that is near perfect, combined with a frequency response with a maximum deviation of +-0.5db from 250Hz-20KHz.
Why do horn manufacturers often exaggerate claimed sensitivity ratings?
Overly optimistic sensitivity rating is observed not only in horn speaker design, but in most speakers, regardless of speaker technology. Unfortunately marketing departments think they can “push” the rating up by a couple of dBs, possibly hoping to gain some sales for owners of smaller amplifiers. Some very-well known speakers actually measure 6db lower than their rated sensitivity. However, it’s quite easy to spot and point out designs that exaggerate claimed sensitivity, simply by analyzing the design, drivers etc. Rating sensitivity is not a race - we think it’s better to just state the actual rating and move on.
ARIES CERAT SYMPHONIA HORN SPEAKERS REVIEW
Fnal review of the Aries Cerat Symphonia horn speakers, with in prolonged musical references...
My journer into the world of Aries Cerat started years back with the original Talos phono preamplifier and extended over the years with few other products, that have always seriously rivaled the competition.
Fast forward to the Aries Cerat Symphonia speakers. Th experience associated cannot be associated with any typical audiophile labeling. These speakers represents something very different...
THE BIG BANG
First impact came as something completely non expecting. Evanescent sound from most speakers easily leave me untouched. Here, something very different and special was on track. In absence of typical peripheral sound imprint, Symphonia speakers prelapsarian archetype like natural sound resolved with a new mystery...
I’m used to freckling nature of many if not most horn based speakers. Most of them sounds fibrously fragmented rather then harmoniously rich and palpable. Aries Cerat horn speakers indtroduced tremendous power handling ability, breaking many of the typical rules expected and connected with this type of the speakers.
Sound at upper plane shall bring low level anxiety, unaltered, unassisted experience that's involving, coinciding with music and without any specific geotagging of the sound and Symphonia's manage to project illustrious benign sound particles, that for a change could formed a clarity and a defined acoustical space. Quite a new dimensional path.
Stvaros Danos non condensed creations resolves through painstaking processes. It all starts with the BIG way of out of the box thinking. He never settles for the dramatic mood impression sole or false impersonations. This DNA unmistakably embraces resilient nature across all of his products.
Next instantly recognized attribute is massiveness. To not everyones liking proper sizing comes as mandatory. High-end companies trend in downsizing also don't exclude expensive and exotic ultra high-end audio products. Commercial leveling pops up to quickly. On contrary Stavros’ components might appear monstrous and the answer is simple. The utmost quest leaves no place for mediocrity reasoning.
Wholeness presented with Symphonia can convey raw musical nature rather then sonic mildness. Different league! Live music, always closely connected with pure energy leveling demands a firm, mighty projective with fullest bloom of pure energy transfer. Symphonia stand still in such projection with a full scale impact and going way beyond the most dynamic speakers big boys scope. With even the most stand out examples the distortion coating is too obvious...
HERITAGE DNA AND OBJECTIVITY
Symphony horn speakers DNA carry some serious homework being done.
Stavros Danos was early on fascinated with the horn speaker technology and soon after embraced it as the only ultimate way to go. Years of research and reading resolved in his appreciation of the prior art, and contemplating about new ideas. Consequently by comparing and listening he failed to be enthused with contemporary horn designs and associated fundamental flaws, that are killing real horn advantages and introduces the problems of their own. He wanted to embrace early horn era designs and take a step further with help of modern advanced technology.
The Symphonia speakers began as Stavros Danos personal project, long before the establishment of the company in 2010.
Many of his ideas and concepts could only be materialized after the acquisition of highly specialized equipment, such as 5-axis work station with the highest Z-axis envelope possible, ideal to carve anything from chosen materials.
Both Contendo and the Symphonia were developed side by side. Experiences gained on both fronts opened up the exchange concepts and innovations shared between two development platforms. For example horn loaded ribbon tweeter innovative 360 degree flare was originally developed for the Contendo, but utilized in final Symphonia design. Same goes for the solid wood midrange horn, with it's special drop shaped enclosure that eliminates all diffraction aslo used and implemented with tweeter horns. This originated with Symphonia project and was later implemented with the new flagship, cost no object Contendo.
Symphonia was not an isolated project, but a design that grew along with the company by adopting many breakthroughs from other speaker projects.
Along with other unique things, Aries Cerat's proprietary variable slope filters, with the constant delay characteristics, were developed over many years during the design of the company's smaller speakers. At the end, Symponia acted as final developing platform extending across complete speakers line.
Lots of R & D time went into eliminating problems associated with horn physic limitation. If the limitations are not considered, horns's sound will result in mediocre performance and with nasty sonic traits.
Badly designed horn speakers sounds much worst than a badly designed conventional speaker. If a horn speaker design is compromised from the beginning, either with budget limitations, tech resource limitations or simply by the lack of horn physics understanding, horns are better to be skipped.
When properly designed, horn speakers represents ultimate electro-acoustic transducer. Both Aries Cerat Symphonia and Contendo speakers follows this path profoundly.
I’m often tease speaker manufacturers to state real down to earth technical specifications. Especially the sensitivity. Most of the speakers are stated at least 6db higher than the real word measured sensitivity. It is easy to spot and point exaggerating only by analyzing the core design, selection of the drivers etc. Rating sensitivity should not be the race, but just plain state of the actual affairs.
Faked sensitivity rating sadly extends to all speaker designs as marketing modus operandi pushes ratings to reach the broader customer base, including owners of smaller amplifiers. Sad, but factual...
FULL RANGE FULL SPECTRUM HORN IMPACT
Full range, full spectrum horn design need to separate true horn speakers from waveguide, directivity control apparatuses, hybrid designs etc.
Horn loading is something completely different in terms of physics, approach and end result. Any over simplified categorization can be shady and confusing.
Horn speaker is by default an acoustic impedance transformer. Car mechanical analogy of 1hp servo motor coupled to a feather like axial load perfectly explains it. Energy transfer of such system is very poor, of low efficiency and most of the mechanical energy is wasted.
On the opposite extreme, 0.1hp servo motor coupled with 1m diameter steel disk sports extremely low energy transfer for opposite reasons, usually related with planar speaker designs. Maximizing transfer of electromagnetic energy to acoustical motor impedance must be equal to the load “impedance”.
A horn act simply as a gear box, matching the impedance of the load to the output impedance of the motor. Sounds simple, but not exactly a free lunch... However as horns are bandwidth limited, they're sacrificing bandwidth for the efficiency.
Full audio spectrum reproduction speaker system should with such logic separate s specially designed horns for specific bandwidth intended. In theory, with world data at hands Stavros feels, how the separates should handle 1.5-2.5 octaves, even if the drivers loaded with the horns can handle much wider bandwidth.
Limited bandwidth of each horn demands additional drivers, increasing cost, size, and weight with full horn loading of the entire audio spectrum. Horn cut off frequency is a function of size. You cannot bend the rules, thus so many hybrid designs.
Full spectrum horn sound is suybordante to horn physics.
Usable extension of first two octaves via bass horns calls for certain length and “mouth” area for given cutoff. A lifestyle stylish speaker idea vanishes instantly.
Aries Cerat bass loading is quite straight forward, even though the technical solutions are not. With Symphonia 3m horn length is related to 3300 cm2 of “mouth” area. Usual norm relate to shorter horns connected with limited bandwidth and presence of ripples throughout the passband.
Symphony implements tractrix flare instead of the conical, strictly avoiding sharp corners. A deviation from actual theoretical geometry and with no abrupt curvature changes.
Standard folded horns construction with conical sections of wood sheets, forms a successive conical section and trying to geometrically approach. Such conical horn was quickly off the table…
Aries Cerat owns 5-axis work station with the 5m3 work envelope and this gave them capability for designing and manufacturing a true tractrix horn with 25 vertically stacked sheets plywood meeting all criteria needed. Vertically stacked sheets of plywood can also withstand the high acoustic pressure present inside of bass horn.
Aries Cerat Symphonia midrange horn is tractrix horn, modified with 360 degree diffraction-less flare. As such a cutoff at least 0.5 octave lower than the crossover frequency was mandatory and 330Hz horn was specifically designed.
The horn and bullet shaped enclosure is manufactured from solid plywood block with thickness of up to 15 cm. The poplar plywood was chosen over other types of plywood as it carries twice the strength/weight ratio. Energy storage is thus halved.
Unique flare was designed to eliminate all possible diffractions, inartistically very different to other horns based designs. Diffraction is one of the major sources of so called typical horn sound character. Properly designed horn based speakers do not and should not have any sound of their own.
Symphonia completely eliminate diffraction coloration and smearing transients, with unique 360 degree bullet-shaped solid-wood horns. But, thats not all. The eleven kg, 4” oversized titanium driver, with a massive magnetic system is connected to the multi-tap transformer, that can tune the speakers according to each room’s acoustics.
TWEETER WITH REAL 101DB EFFICIENCY
The development of the Symphonia’s tweeter was spread throughout a three year long journey. Stavros was always fond of Raal designs, yet normal direct radiating ribbons lacks the punch and dynamics of a good HF compression driver. However no compression driver can resolve with details, accuracy and bandwidth of a true ribbon transducer. Getting the best of both worlds embarked for a new quest.
A normal ribbon is not designed to operate with high acoustic pressures at the “throat” of a horn. Special ribbon developing was mandatory resulting in Raal tweeter with modifications.
This particular new horn flare design is loading the ribbon as a true horn and not as waveguide or any directivity control apparatus. The line source emission characteristic of the ribbon made this task extremely demanding. During the process total of 15 different flares were designed, build, measured and discarded before settling with the final design.
Aries Cerat unique diffraction-less 360 degree horn technology was implemented, but with the unique ribbon horn, making the time domain performance of the tweeter unmatched.
Diffraction is secondary sound emission, and it takes place in geometry anomalies, transitions of geometry and changes in curvature. It is very much audible and almost impossible to eliminate. With round horns, diffractions are present on the horn termination. In rectangle horns the problem is even worst.
Expanded 360 degree Aries Cerat horn was born, that could maintain the flare curve’s second derivative constant, keeping the curvature slope constant.
Precise measurements were made with each horn iteration to match the simulation and theory to its practical performance. In his quest Stvaros discovered, how variations of just 0.2mm bring detrimental effect on the performance of the horns. Anyone can imagine what a challenge this was.
The ribbon-horn combination response was shaped to measure flat from 3KHz upward, and could deliver detail and resolution that only the best of ribbons can (combining a solid punch and dynamics of the best HF compression drivers). Distortion numbers at 114db were lower that those of the best dome tweeters at 95db. A real step forward...
Horn speakers done right are acting as a true magnifying lens, closely inspecting everything in system chain. We can call them unforgiving.
With highly sensitive horn speakers being driven at normal listening levels first few milliwatts are of utmost importance. Low passages, ambience, sense of space and timbre are very well hidden many db below the level of fundamental instrument notes.
Most sensitive speakers are driven by default with just a few watts of power for peak signals, thus integrity of the signal in very low power output is essential for the highest reproduction.
Heavy and inefficient speakers can “perfectly mask amplifier first watt artifacts, yet horns are very direct and unforgiving when driven by amplifiers designs created for the conventional speakers.
This is where solid state and most push pull designs fails. The first milliwatt!
SYMPHONIA VS OTHER HORN BASED SPEAKERS
Sadly past horn designs are to quickly put into the same box of so called wisdom. Many of the old designs are landmarks of audio reproduction and can show the new guys how job should be done.
But, some of the old designs were very much flawed and extremely colored for today’s standard. One must be careful and evaluate each design as its own.
Problems of contemporary horn speaker are associated with two things.
- the lifestyle-oriented design
- the lack of knowledge of basic horn physical principles
Sadly many of the design choices are made with aesthetic priorities in mind rather then prioritizing functionality and objectively following horn physics.
This is clearly a matter of deliberate design choices, many times ignoring basic horn principles.
Speaker engineers of the past had different priorities. Although without CAD-CAM simulation systems and programs, their designs respected the basic and advanced aspects of horns, with forward thinking attitude.
With Symphonia project Stavros Danos decided to address problems associated with the implementation of a horn theory. He also wanted to bring solutions to practice and realize actual production. No shortcuts were taken and this led to a custom diffraction-less horn, specialized constant GD filters, unique bass horn design and special tweeter. Symphony materialized into a platform referencing to how contemporary high performance horns should actually sound, as well as forming a speaker design small enough fit though normal doors (although only disassembled).
Horn speaker designs requires addressing some of the issues that physics dictates:
- budget issues
- manufacturing capabilities
- technical knowledge
Going into over-stylizing and neglecting basic facts results in mediocrity. Many would be better of with conventional technology speaker design as badly designed horn speaker sound much worse than a badly designed conventional speaker. A fact!
Horns physics dictate all of the aspects being addressed with utmost attention.
Many if not most horn designs on the market fail to address proper flare for the bandwidth and use too wide bandwidth for a specific horn.
A specific horn has a specific bandwidth and should operate optimally. Usually, designers “stretch” the horn’s passband to get away with less horns/drivers for a particular design
This makes design smaller, aesthetically more appealing, easier to manufacture, making less parts needed.
But, horns that operates in the wrong bandwidth presents a high order and linear distortions. Flare accuracy is very important; the higher the frequency, the more accurate flare is mandatory.
Aries Cerat tractrix flare was chosen for the best measurments and subjective performance.
Stavros feels strongly how rectangle horns present high order distortions and many diffraction sources. Horn diffraction problem is the major factor in creating the honking sound that most horn are associated with.
Symphonia drop shaped midrange and tweeter horn enclosures with bullet shaped 360 degree horn flares addresses this spot on. Painstaking to design and execute, but this solution seems to avoid the hubris existing in other designs.
Looking at many popular modern horn based speakers reveals improper implementation of the drivers. Not all transducers are suited for horn loading and as such misbehave when they're loaded with horns. Proper drivers are usually expensive and hard to aquire. Finding the best driver for the intended bandwidth is a complex quest as technical specification can only indicate some of the reality.
We have all sorts of construction materials being used for horns these days. As a fact horn presents sound pressure levels exceeding many times the pressures of conventional speakers. Plastic or aluminum horn however thick it may be, will ring, resonate and color the sound immensely. This can be a complete nightmare.
Symphonia listening and measuring tests called for a 2.5 cm thick composite. A 330 Hz tractrix horn was compared to an identical stacked poplar ply wood horn with 15cm thick walls. Measurements of burst decay and listening tests revealed how plywood horn is vastly superior, even though 3 cm composite horn is much thicker than the market’s standard. Unfortunately you cannot mould inject a 15cm thick plywood horn,so manufacturing one from scratch is much more laborious and costlier....
Horns are also very sensitive to their termination geometry that follows after the flare (mouth) ends. Discontinuities of the geometry drastically changes in curvature, generating secondary emissions. This delayed emission returns back to the horn throat/horn driver and radiates towards the listener. These horn diffractions are very audible, especially with horns installed on the baffles.
You've probably realized so far. Nothing is easy or can be simplified and Aries Cerat Symphonia horn speakers shows the complex nature on each turn.
Aries Cerat Symphonia went through diversified musical material challenge and these are not the speakers you would pin point to a certain genre.
Still… When it comes to the reproduction of un-amplified, live and acoustical music, I would take instantly any speaker that perform well with these particular material over a specific jack of all trades, master of none voiced loudspeakers. Symphonia ability to act authoritative across broad specter of music without a special magnetism towards any particular genre was more the just inspiring.
I’ve made many listening notes during the evaluation, but this particular focus will reveal how complex and vibrant Symphonia heart at once.
Lucia di Lammermoor, a dramma tragico immortalized by Inva Mula performing as Diva Plavalaguna in the iconic Luc Besoon’s film The Fifth Element, is not only tour de force for the singer, but heavy, hefty load for any speakers or system. Not heavy in the terms of enormous sound pressure, but heavily subtle.
Human voice, as simple as it might appear and as much as some audiophiles want to simplify it, is a complex instrument of endless sonic cues and anchor points. This particular lyric soprano opera performance, also nicknamed the "The Mad Song" can to quickly become exasperating without the proper expansing of the decays and delay, that forms the constitutional vocal illusory cues.
Aries Cerat Symphonia expertly rendered tonal density, musical energy and exclamation marks and managed to encapsulate consistency and density, that are natural to any real sound. The authoritative nature, embraced by coherency revealed deeper and more vivid sonic voyage.
What might seems aberrant for a non demanding or quick listener comes in a form of actual correctness. Symphonia’s unique ability to reproduce in its core a realistic harmonic tails rather then artificial and exuberant imprints, let Inva Mula vocal to flourish, linger and establish the extravagant emotional bound.
Phase related timing problems are among the very first things, that always puts me off. This reflect with the artificial portraying of the human voice and in a needed believability. Symphonia let subito fortissimo to emerge and expand with non typical balanced evenness.
Even the top tier dynamic speakers can act plaintively and hushed when it comes to the sudden attack shifts. Symphonia ability to go beyond well versed has proven again and again with versatility, that is to far fetched for what can be expect with the typical speaker design.
Even when vocal’s articulations leapfrogging is joined with the instruments nothing falls apart. Balanced act was splendid and emotional bounded to the very inner core of the music.
All in all, Aries Cerat Symphonia horn speakers allowed the sonic extravagance to take new proportions and dimensions, that are reserved for far bigger and mightier speakers. Having such performance with this given size is a grand achievement and an act of war towards the competition :).
Sguru - Take 5
Most of audiophiles and music lovers needs no introduction to the Dave Brubeck’s legendary song Take Five. I’m more then sure, that some of you even had too much playtime.
Anyhow, the Sguru rendition is something special. The drum intro resolve in a unique dynamic blast, that is packed with energy and vibrancy. This is a true heavy league demanding task for any speaker, as it goes beyond of just hard to portray momentum. It calls for balance and synergy with the un-altering dynamics, that can render believable scale and tension. I’m not talking only about the drums intro. When the rest of the band kicks in the second challenge awaits. To some extend some speakers might hold sort on the facade reproduction with the small portion of the drum’s crescendos. But… When the instruments joins in the break apart mode hits the reality check at once.
Aries Cerat Symphonia speakers managed to convey both thunderous drums intro and rest of the song validly and without pushing the music onto the stress plane and without loosing the focus at any time. This was a triumph of the seamless dynamic impact.
Bela Fleck And The FleckTones - Flight of the cosmic Hippo
Guitars and bass in the fullest scope. This is one of the tracks you’ll want to impress your visitors and yourself if the speaker system allows it to.
Its also one of the tracks that particular well point towards the speaker’s ability to handle the sheer energy transfer. While many traditionally designed speakers are trying hard to convey the energetic impact of the this particular track, few of them can actually deliver the sense or realism without collapsing while doing it.
Some speakers can encapsulate the mid frequency range to the believable scale, but Aries Cerat Symphonia horn speakers goes beyond typical speakers calibration. They’ve managed to endure the physical momentum, that is more intimately correlated with bigger horn systems, then the Symphonia’s given foot print. The distribution of energy across all frequency in mandatory with Flight of the cosmic Hippo and Symphonia embodied David’s lighting fast attributes with a Goliath power, without loosing the impact at any time.
Carmen Habanera Fantasia - Northwest Sinfonietta
Interestingly, for most of the audiophiles and music lovers big horn speakers still represents the ultimate, state of the art speaker’s system. Anyone who have had a chance to experience the true potential of the large horn system will hardly return to the more mortal dynamic speaker’s explorations. The effect of the proper sounding horn system remains lingering for good.
There is a world of difference at 100+dB sensitivity, where the sense of drama and realism is accomplished in much “easier” way. This is especially evident with the orchestral music reproduction.
Carmen Habanera Fantasia holds so many of the musical shifts, that expands across across the score and call for a fast tracker. Bizet expertly created a masterpiece, with immersive lyrical impact and emotional charged potency, that simply waits to burst out.
The real “magic” starts to form with the speakers ability to render the energy “bubble”. This is the phenomena one can experience with the live orchestral music, where sound is traveling in a virtual bubble form, that holds everything, yet still allows the singularities to be be distinguished. Not many speakers can accomplish this task in the right way and it one of the downsides of even top tier dynamic speakers. Do note, that not all horn speakers are able to produce this experience in the right way. There are quite few contemporary “quasi” horn speakers, that are holding more dear the design exuberance, rather then intrinsic horn qualities and this shows instantly even with much “simple” tracks.
Aries Cerat Symphonia goes beyond entrapping, prismatic sound barriers, that most of modern horn speakers somehow took as their own signature.
Carmen Habanera Fantasia needs the fullest bloom across the complete frequency spectrum to really flourish and Symphonia’s were able to deliver both emotional and dynamical drama without reservation.
I’m often stopped at the audio shows and pointed to experience something particular great. Yet, if the system or more precisely the speakers cannot transcends the pin pointed sonic entrapment, then its hard to feel utterly excited. I can surely understand certain audiophile peculiarities, but they have nothing to do with the way the music sounds like in reality. And this is the what sets apart the Aries Cerat’s horns. They’re embracing the music for what it is, rather then what an acoustical designer wanted to. High-end audio speaker design is indeed an art. But, an art of realistic music reproduction and not the art for the art sake. The sonic outcome of Aries Cerat horn speakers is acting contrary to the most of the contemporary horn speakers. Symphonia’s play for you rather then shout at you. Yes, the listening fatigue doesn’t appear even after prolonged louder listening. Try this with some German glorified horns. I’ve been there…
Carl Orf - Carmina Burana
Portraying the sense of the full orchestra and Choir in domestic situation seems like a far cry out. In order to create the atmosphere of Carmina Burana speakers needs to disappear and act with the potency of micro and marco sonic lenses, that can mirror the realistic gravitas of the orchestra.
Carmina Burana poignant narrative holds no prisoners. This is the emotional and energetic tour de force, that shows no mercy to the system and speakers under the “stress”.
Its all about the emotional rawness and vibrancy, that needs a proper transducer to act alive and wholesome. In absence of murkiness Symphonia (while driven with full Aries Cerat electronics stack) materialized a profuse experience, that hit all the senses at once. Symphonia exhibited a rare value, where music actually reaches out directly to the guts in prior of the triggering functions of the upper cortex. That alone is worthy of applauding even before going further.
One of the grander challenges for any speaker is proper balance of all the attributes. Even harder to achieve is the rendition of believable relief like structure of the orchestra and surrounding space. So called virtual three dimensional atmosphere with proper layering is a challenging task that Symphonia refreshingly excelled at. Non standard density allowed for Stavros Danos’s horns to materialize aural vertex. The onerous task of portraying the orchestra is strenuous work and Symphonia coped with depth in music on the very, very different plane.
Let me add the functional tonality. Symphonia has a rare exemplary ability to develop motivic development without bumping into the technical shortcomings, that are too often, too audible.
When seamless potency goes unnoticed, then sound can freely expand in all directions. Point is, that if nothing stick out, there is something more then right going on under the hood. It becomes a distraction-less experience. I’ve couldn’t summarize Symphonia’s ability to reproduce Carmina Burana in a better way and more objectively.
Andrei Gavrilov / Riccardo Muti Rachmaninov: Piano Concerto Nos. 2 & 3; Rhapsody on a Theme of Paganini
When it comes to piano playing any performer will be compared to the giants like Martha Argerich etc. Andrei Gavrilov might not have lighting fast action as iconic Argentinian pianist, but he is well accomplished and able to play with virtuosic density, that quickly drawn you into the Rachmaninov world.
Andrei Gavrilov might take technical side before emotional bund, but thats quite a risky observation, as Rachmaninov demands both utmost technique and emotional compass both aligned.
Nevertheless this recording is among better ones and call for balanced and lighting fast system to reproduce the complete atmosphere in its fullest impact.
Aries Cerat Symphonia speakers could act both stridently and punctual in rendition of Andrei Gavrilov and Philadelphia Orchestra when needed. The tactile, immersive rendition submerged in a palpable stage localization not expected by any means from the speakers of this size. They have simply disappeared and left the listener to logically follow the cues.
Symphonia unique advantages morphed with objective attributes. Imagine combined natural scale with seminal fast sense of reality.
Its never easy to render piano in right way. Its even harder to portray orchestra and piano jointly with a sense of accomplishment. Either one or the other takes the forward initiative and leave the other one less distinguished. Aries Cerat Symphonia refreshingly conveyed Rachmaninov with the sonic performance, that could easily emerge and expand according to the score and emotional narrative.
The level of acoustical information density and focus anchor points, that Symphonia managed to reproduce brought to live this particular album with the mighty, stand out truism. Piano and orchestra’s harmonics and trills emerged with perpetual energy, that was both instantly engaging and captivating.
Aries Cerat Symphonia speakers ability to portray the condensed nature of the music without constraints and resiliently, letting the core of the music coming forward without any of the usual obstacle, makes them not only refreshingly different, but even more important, constitutionally right!
What makes Stavros Danon standing out of the crow is fanatical determination, impressive knowledge, restless spirit of continuing experimentation and perhaps even most important; the time, funds and tools available to explore ultimate horn designs.
And the result is something so utterly different, that demands an open mind and matured set of ears to fully appreciate it.
Similar to all Aries Cerat product, Symphonia horn speakers are all about energy transfer. This might sound a bit oversimplified. Yet again, its one of the rarest thing to experience in full bloom with any kind of speakers.
With typical array of speaker designs we’re more or less always dealing with a certain enclosure imprint. The only exceptions might be electrostatic, dipole and ribbon based speakers, but they have their own set of challenges to deal with.
Simplicity always comes from complexity. Without understanding the inner mechanics of acoustics and without hands on experimentation, the end result is farer from the truth. And such manifesto is too often advocated as state of the art.
Aries Cerat, Symphonia speakers can render the music with both feather like lightnes and thunderous strike within minute change. This is crucial with classical music reproduction where sudden attack dynamic shifts demands a conductor of higher potency. More things are connected with the sheer speed of the sound, then we might understand and Symphonia is a primer example of the speed being rendered spot on.
Symphonia is all about realism and drama and for sure won’t satisfy audiophiles, that are only looking for the glare. This is straight forward marching contender, that intimately reflects Stavros Danon persona.
In the search of the grander audio illusion Symphonia horn speakers have opened up a new chapter by combining the horn speakers heritage principles with quite few 21st century genuine twist. I’m yet to hear the speaker of Symphonia size gravitating so closely towards the reality.
Let me conclude the review with the Baltasar Gracian quote: “Ears become the back door of truth and the front door of deception”
To many times, this exact phenomena takes a part in our beloved world of high end audio. On contrary, Aries Cerat Symphonia stands on its own as a healthy and bold antidote to some of the highly sought after expensive big boys toys. They are true gems and a sobering slap of reality.
Aries Cerat Symphonia speakers are unique creations and deserve all the given praise. For what they represent and how close they can push high-end audio performance closer to the reality, I’m wholeheartedly giving out the Mono and Stereo Editor Choice Award.
Sensitivity : 101db Frequency response(-3db) : 32Hz~100Khz