Cessaro Horn Acoustics

Cessaro Horn AcousticsCessaro Horn Acoustics create bespoke horn speaker masterpieces. With exclusive technique, state-of-the-art technology and exceptional workmanship, Cessaro evolve the horn speaker concept to an incredible new level. Aside from their significant design and engineering achievements, these creations simply sound extraordinary.

Cessaro Horn Acoustics was established in 2006 by Ralph Krebs with one goal in mind: To manufacture horn loudspeaker systems which can faithfully reproduce live music in your home. Ralph’s determination to not compromise on any detail in his single-minded quest to build a loudspeaker without tonal limitations took the concept of high-end to such extremes, that many in the world’s audio press have stated that Cessaro products are the definition of high end in its purest form.

It takes extraordinary effort to produce a loudspeaker system designed to provide the best possible musical experience for the audiophile enthusiast in the privacy of one’s home. The manufacturing techniques employ bespoke craftmanship usually reserved for the finest furniture & coach-building cottage industries. Many of the components used in these loudspeakers originate from aerospace and military applications. Most of the compression drive units are specially made for Cessaro and are not used in any other loudspeakers. Their horns are made from a new proprietary composite material, a two-shell fiber construction with a polymer filling, fully sealed with a CNC machined aluminium flange and are extremely heavy. The list of unique and extreme materials & technologies is endless.

Buying a Cessaro Horn Acoustics Loudspeaker system is a lifetime investment and signals a serious commitment to the love of music. The Cessaro modular line (Alpha-Beta-Gamma) allow for an extensive speaker configuration upgrade path. Cessaro engineering and support is extensive, including assistance with installation, positioning, room treatment and sound optimization. It is a life-long relationship to ensure supreme enjoyment of your music system. Just having the opportunity to listen to a Cessaro loudspeaker system is a memorable experience, let alone owning them. From idealists for idealists.

Cessaro Omega 1


What makes Cessaro horn speakers different to ALL other horn speakers?

Cessaro Horn Acoustic aim to produce the best horn loudspeakers possible by ensuring a totally uncompromising approach to design, components and construction of their speakers. No corners are cut, the technology is cutting edge, the quality is heirloom and the attention to detail is extreme. Below is a brief explanation of the technologies that are unique to Cessaro horn speaker design.

Cessaro Horn Technology

The design and implementation of the actual horn is fundamental to horn speaker designs and is critical to achieving ultimate sound quality. Every single detail matters. If the shape, weight or the softness of the inner damping material changes slightly, the sound quality is affected. It has taken Cessaro many years of research, experimentation, working with experts in specific fields and ultimately…. simply listening to get these details right.
The horn shape, the inner damping polymer, the construction technique and the composition of their horns contain technologies that cannot be found on ANY other loudspeaker systems in the world. Unfortunately, producing such designs comes at a cost with the cost of one Cessaro horn alone often costing more than some other complete high-end speaker designs. However, there is no other way to achieve these results.

Horn shape

The horn shape is one of the foundations of horn loudspeaker design. There are many different horn shapes used in audio, including exponential, radial, tractrix, constant directivity, bi-radial, LeCleac’h, quadratic…just to name a few. Cessaro developed their own software which simulated the performance of every possible horn shape and spent 2.5 years researching and developing their horn designs. Ultimately, they developed a custom designed spherical horn shape with some modifications at the horn mouth to create a softer wave at the edge. This produces fewer secondary waves and results in a more accurate, cleaner, more open sound.

Horn construction and inner damping

Cessaro manufacture their horns with a double shell, internally filled with a heavy polymer. The special composition of the polymer is critical as it has a specific density that is not too soft or too hard in order to provide perfect inner damping characteristics.

No adaptors

The horn throat is made from an one inch thick solid aluminium ring. Within the throat ring is another aluminium ring which is inserted to keep the driver in position and the compression driver is fixed directly at the horn throat, directly coupling the driver with no adapter in use.

Horn weight

Due to these construction methods, Cessaro horns are very heavy. The horn alone (without the driver) is 7kg for the Wagner, 60kg for the Alpha, over 100kg for the Beta and over 250kg for the bigger horns.

Cessaro Horn close upCessaro Beta II B4

Cessaro Drive Units

Why is driver quality so important with a horn? Put simply, if the drive unit has poor sound characteristics or a specific sonic character, those attributes will be amplified by around 10dB by the horn. Once you have unwanted driver-induced sonic artefacts, you really can’t fix the sound. You will always hear it. Since horns are so revealing of the driver quality, sourcing and matching the drivers correctly is paramount.

Cessaro predominantly use custom made TAD drivers however in the last five years, Cessaro have found it more difficult to source compression drivers and paper cone drive units that meet their requirements. In response, they have embarked on custom collaborations and increasingly more in-house development and production of drive units. This has improved flexibility, quality control and has ensured sustainability and future support. In some cases, special custom drivers are also available by special order and can be fitted into Cessaro horn systems.

Cessaro Custom Driver: 42KG GIP FIELD COIL UNITCessaro Custom Driver: 18" BASS GIP FIELD COILCessaro Custom Driver: TWEETER GIP FIELD COILCessaro Custom Driver: FULLRANGE GIP FIELD COIL

Cessaro Time Alignment System

Since so many factors can affect the final sonic performance of a driver coupled with a horn, then it is undesirable to simply have the horns in a fixed position. Furthermore, adjustability is also required to account for seating position, room shape and other acoustic space influences.

Cessaro has built a special time alignment system for all of its modular horn systems and for some other models. This incorporates a very strong base plate where the heavy horns with drive units can be fixed. On top of each base plate is a CNC-machined linear element mechanism including a spindle to rotate the moving plate towards the front or back of the speaker. This enables the ability to make precise adjustments of the horn position to within one tenth of a millimetre! For those customers who desire it, a digital display inside the rotating knob can be ordered as an option.

The adjustability does not end there. Cessaro also provide a solid stainless steel mechanism to acutely control the firing angle of the horns. Only with the ability to make fine adjustments are you able to find the correct position for proper driver time alignment and adjustment for listening position & room influences.

Cessaro detailCessaro detailCessaro detailCessaro detail

Cessaro Crossover

When you have high quality drivers coupled with well designed horns, the slightest imperfections are revealed, so crossover technology is vital. It is relatively cost-effective to make a crossover that simply fulfils the role of dividing an audio signal into multiple frequency bands. However, to make a crossover that performs at a very high level sonically is difficult to do.

An appropriate analogy is comparing a fast food cook to a Michelin star winning chef. The quality of the products are very important but knowing how to use the ingredients, at what time, in what place and in which portion is the key and can result in wildly different results.

Aside from using high value capacitors based on pure silver MICAS technology, Cessaro design their filter networks with a focus on the psychoacoustic properties that are most important for human ears. Together with their time alignment system, their speaker systems can be individually adjusted at each client’s listening space to suit the client’s electronics, room behaviour or personal tastes.

Cessaro Cabinet Quality and Weight

Cessaro cabinets are constructed to function effectively as the structural backbone of the speaker. Aside from lasting a lifetime, they also must also look great to complement the overall product quality and to provide a pleasing aesthetic ownership experience for the client. To that end, Cessaro employ the most accomplished artisans in Germany to finish their cabinetry to coach-building standards. The exceptional craftmanship is evident in every speaker, perhaps most obvious in the ArtDeco model which exhibits the most exquisite wood crafting perhaps of any speaker in the world. Each cabinet is hand made by one master craftsman using old woodcraft techniques and takes months to finish.

Cessaro speakers are also notorious for being very heavy. For example, their smallest speaker the Wagner weighs 220Kg per pair and their most advanced speaker, the Omega is almost 5,000kg per pair. Cessaro owner Ralph Krebs recently commented on this:

“I know that we are well known for heavy products but it’s not because we like to carry heavy things! Believe me, we wish we could achieve the same results at a much lower weight, but it’s just not possible.”

Even from the weight of their components, it is easy to see how distinctive Cessaro are from ‘standard’ high end speakers.

Cessaro Artdeco and Gamma II Speakers
Cessaro Cable

Cessaro have developed their own pure silver cable to use throughout their speaker models based on what they believe is the best match. For perfect continuity, the same cable strands run through from the input terminal to the crossover and from their output to the drive unit. Active bass units also have the same cable. The whole speaker system is wired with pure silver cable – consistent wire technology. Clients can even purchase the same cable to use externally for perfect system matching if they wish.

Cessaro Driver Integration

Many horn speaker designs suffer from poor integration of the bass driver units with the horn midrange. There are a number of reasons why this phenomenon happens. For example, trying the integrate a front loaded low-mid bass horn with a conventional bass cabinet with very low efficiency makes seamless integration impossible however it seems to be evident in high end speaker designs.

Other designs use a long-travel bass driver in a cabinet with an extremely short front horn. Due to the short horn, this design is very limited in its ability to produce low frequencies so to compensate, the design incorporates an equalizer and a boost at lower FQ to produce the lower bass notes. Although this design succeeds in producing lower bass notes, the bass is slow and ‘heavy’ and sounds different to the notes produced by the higher frequency horns. The difference in the nature of the bass is immediately noticeable and perceived as poor integration.

With the Cessaro Liszt, Beta, Gamma, Zeta and Omega, the speed of the drivers integrate seamlessly at the carefully selected crossover points so it is not possible to hear any integration issues in that range. The Alpha II’s cross their 16“driver with the compression driver at around 500Hz and achieves the best performance of a speaker of that design in its class.


Due to the fact that Cessaro Horn Acoustic systems have to fulfil the highest acoustic performance demands, they offer a multitude of options for technical (sonic) adjustability. The company embraces the concept of customization and individualisation of its speaker systems, only limited by the ability of the system to reproduce music faithfully. Also, virtually unlimited aesthetic, wood finish and horn colour options exist so that customers can be fully satisfied with their loudspeaker system on every level. The very top of the range Omega Systems are fully customised to the client’s listening space.

Cessaro Electronics

Cessaro Horn loudspeakers are extremely revealing of the quality of the upstream sources and electronics. In fact so revealing, that client’s find that these speakers need to be matched with the finest electronics. One particular client in Europe which had a custom Cessaro Omega II system installed, engaged Cessaro to source the best amplifier for his system. After many trials and auditions of the available high-end amplification options, Cessaro decided that it needed to design an amplification system that would be able to perform at such a high level, that it could drive their speaker systems to their potential.

Cessaro engaged Ypsilon Electronics and both companies collaborated to create a pre-amplifier and power amplifier system that incorporated extreme quality componentry, the highest grade pure silver transformers and a topology that was unparalleled in the market. The Cessaro Air One and Air Two amplification systems are a revolution in ultra-low noise, hum free, short uninhibited signal path design. A perfect match for Cessaro Horn Acoustics loudspeakers.

Cessaro Air One PreampCessaro Air Two

An Audiophile’s Dream

When you meet Ralph Krebs, Cessaro’s founder and CEO, the reasons for the company’s success become immediately obvious. Putting aside his immense knowledge and uncompromising approach, he is really interested in his customers and ensuring that their ownership experience is second to none. Ralph regularly accepts invitations to come to Australia from Germany to lead the installation, set-up and optimisation of a client’s new speaker system, then happily visits existing installations to listen & tune their systems. Clients often get to know him personally and he refers to them as ‘family’. It’s not just about making a product and shipping it out the door to a distributor. Ralph stands behind his product and his enthusiasm for achieving great sound is contagious. This human care factor is an intangible, yet very important contributor the Cessaro ownership experience.

Every little detail makes a difference. Quality matters even if the client can’t see it.
Ralph Krebs

Cessaro website
Our visit to Knox Audio

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