Divine Acoustics

The process of speaker design is very complex. Many of the components, such as the electric system, the resonance system, wires, as well as the cabinet and its dampening, are subordinated to speakers’ trembling diaphragms. Furthermore, these components not only cooperate with each other, but also constitute the integral entirety – the extraordinary musical instrument.During the process of designing, the most important thing is the fact that the right synergy of all components enables to create speakers which convey the natural sound of musical instruments, natural atmosphere of the Recordings, the rhythm, emotions...

The short story

Music appeared in the first weeks of my life. On the one hand it was something natural for me and on the other something essential just as food, drink or sleep. Over the course of a few years, the activity of listening to music became my great passion. What is more, I started to pay  more and more attention to the quality of sound. In October, 1996 in Warsaw there was the only concert in Poland of Michael Jackson. The concert had such a perfect sound system that I must have held my breath in amazement. That event constituted the turning point in my life. I realized then how faulty and imperfect my musical player equipment was. After coming home in a state of excitement, I wanted to listen to the same songs all over again in order to feel that atmosphere one more time. However, after a few sounds my disappointment set in! The speakers that I had at that time gave out something… indeterminable.

These average speakers were produced by some worldwide company and, therefore, I expected much more. At that time I realized that the speakers did not sound as perfect as I wanted them to. I was a teenager then, so I could not afford to buy more expensive and equipped speakers. An a result,  a thought crossed my mind. The idea was to create speakers that could give the joy of listening to music. What is more, these speakers should give out a sound like I heard during that concert and they should not cost a fortune. The process of designing the speakers turned out to be very complex and labourious process which is full of unpredictably , sometimes I achieved results and sometimes moments of doubt, even despair.

To create speakers, that would be good in sound and appearance and that I would be proud of, took nearly three years. I named these speakers Altair which means "the flying eagle". One of the stars in the sky is named Altair. In that way I was able to combine my two great passions which are music and astronomy.The Altair speakers were improved many times and their sound was transformed few dozen times.  I was in search of something undefined which I felt my speakers lacked. The process of creating these speakers showed me the complication and extensiveness of the process of designing the speakers’ cabinets. After many months of designing, testing many various alternatives, listening to again, simulating on a computer, the speakers came into being. Their main characteristic was that they gave some resemblance of live music. After so many years of gaining experience in designing, I am now aware of my first speakers’ imperfection.  These Altair speakers enabled me to learn how design the speakers efficiently. Only pair of them was created and they still work now.As the years went by I designed more and less successful speakers for my friends and acquaintances.

Thanks to that I have become more and more experienced in designing. In 2007 an acquaintance asked me to create a near-field monitor. Its purpose was to be used in his recording studio at home. In the final phase of the project my friend – audiophile visited me. I asked him to assess its sound. He was very astonished by the sound and encouraged me to create the speakers for audiophiles on the basis of these monitors. For the reason that there were many perpendicular cabinets all over the shops, I decided to design a project which would stand out from others.Since I was a child I was fascinated by science fiction films, the future technology and stars. One of the ground-breaking movies in the history of cinematography is Stanley Kubrick’s A Space Odyssey 2001’. The very important part of this movie was mysterious monolith made of unknown material. It became the inspiration for my project. So called Proxima came into being. As it turned later out, its name was metaphoric.

The Proxima means ’first'. As my first project the Proxima speaker was reviewed by a specialist magazine and, surprisingly, it was awarded by 'Best Product 2008' award in the highfidelity.pl magazine.  Since my first projects they have become more elaborate over the years and resulted in the development of BAD and SGP systems which are described later in the text. It is also the first of my project I released from Poland. Also it is the first flat multilayered cabinet and became the precursor of speakers models which Divine Acoustics offers now. Proxima project was originally created as a near-field monitor which provided quick and impulse sound with the least possible distortion. However, that idea evolved into a unique design in speakers. Nevertheless, that speaker is encased with a sealed cabinet. Thanks to the sealed cabinet, the speaker takes advantage of its virtues, but, simultaneously, there are disadvantage with the lack of bass-reflex features. The following speakers I developed, so called Electra and Antares cabinets, were equipped with bass-reflex and based on technologies developed in the making of Proxima loudspeaker.  During the initial years of designing the speakers’ crossovers, I used computer software. With the usage of that software I carried many simulations out. What I have observed was the fact that the results achieved by computer and the sound which I heard did tally. I had to spend many hours in concert hall, thousands of hours listening to music and, therefore, exercising the hearing. As a result I have worked out the scheme and the algorithm for designing cabinet sets. I have not used any computer software to design crossovers since the developing of the Proxima. The sound of every cabinet model constitutes the result of few months’ hearing-through-tests and the selection of components which harmonize with each other creating the final effect.

Visual design

Divine Acoustics speakers constitute the coexistence of modern design and hand-made carpentry. The remarkable visual impression is achieved through the combination of beautiful figures of exotic wood, leather and the slenderness of the floorstanding cabinet. To achieve such an effect the 'golden division' – in other words gold proportion or divine proportion (lat. divina proportio) – rule was taken into account during the process of designing the shapes of all kinds of cabinets. The golden division is derived from antiquity and since then the exceptional aesthetic effects are ascribed to it. Designed in this way shapes possess harmony and are described as beautiful.   The idea of Divine Acoustics' designs was to create not only products to reproduce sound, but, above all, an elegant shape which remains in harmony with the interior décor.

The cabinets

The cabinets of the Divine Acoustics speakers are designed with CAD software. They integrate the sui generis look with elements which are required to gain the proper sound of mounted speakers. During the process of designing the three dimensional model, precise technical drawings and templates for all of the elements are made. The templates ensure the repeatability during the production of all units. Peculiar resonances of the cabinet are damped using multilayer walls built of different dampening feature materials – in every cabinet there are at least 6 different structural and finishing materials. At the bass speaker height the cabinet is reinforced by using steel bars which form the rim. The high frequency tweeters are mounted into the main cabinet with the usage of damping layers. The tweeter of the Antares speakers is mounted in the separate cabinet.

Resonance of the flat cabinet

According to the Helmholtz’s rule of resonator, which describes working of the open speaker cabinets, the frequencies which are radiated by the opening in the cabinet are being displaced in phase against the radiation of the speaker. This displacement increases with the decrease of frequency and is approaching the value of 180 degrees and, thus, is cancelling the radiation from the speaker. The phase displacement of the resonance frequency of the cabinet – where the bass-reflex exhaust works at maximum level – accounts 90 degrees in comparison with the speaker’s radiation. The best placing of the bass-reflex exhaust, which gives the lowest frequency response and the lowest possible phase displacements, will be by the 90 degrees to the speaker. By placing the bass-reflex exhaust at the bottom of the speaker’s cabinet that kind of radiation rule may be achieved. Additionally, that kind of placing of the exhaust gives the cabinet the ability of less excitation while is placed near the wall of the room and also the distance between the exhaust and the nearest reflecting surface (floor) is always constant.

Acoustic transducers

The process of selection of the suitable bass speaker – with proper mechanical, electrical and sound qualities – is the key to gain the proper final sound of the speaker. There are many speakers in the world which differ in parameters, kinds of used materials and prices. During many hours of hearing through tests and as the experience in designing was being carried out, the sets of speakers’ parameters were determined in Divine Acoustics workshop. These parameters are very important for receiving dynamic and natural sound of the speaker set. The speakers, which are applied to the cabinets, possess diaphragms with appropriate relation of vibrating mass (Mms) to the efficiency (SPL) and the basic resonance (Fs). Many companies produce speakers with very low resonance of diaphragms, however, in such case the diaphragms are too heavy, or the efficiency of such a speaker is too low. In consequence, the speaker is too quiet. The speakers chosen by Divine Acoustics the relatively high efficiency (above 88 dB), the small mass of diaphragm and the resonance below 40 Hz. Parameters mentioned above are connected with the following: combination of total Q factor (Qts) of the speaker and the speaker’s equivalent volume (Vas). Many speakers possess the total Q factor which is suitable for the bass reflex cabinet; however, their equivalent volume often is very high. Thus, the designed cabinet must have the very great volume and, consequently, the light diaphragm of the speaker must move the great amount of air in resonance system. Such process is not in favour of gaining the quick and impulse bass. Therefore, the speakers which are applied by Divine Acoustics have the proper combination of required volume of the cabinet and the mechanical susceptibility. This combination enables to achieve very efficient impulse characteristics. When dealing with selection of the appropriate bass speakers, the most important criteria are their parameters and sound. Therefore, neither the price, nor the trends in using the speakers of company X or Y do constitute the main criterion for selecting the speakers. Moreover, not every expensive speaker possesses the proper parameters or not every speaker, which does possess the proper parameters, sounds good. High frequency speakers used in the Divine Acoustics designs contains very light silk domes. The magneto static ribbon tweeter used in Antares model constitutes the custom Divine Acoustics design.

What’s BAD?

Every speaker generates vibrations when working. This process creates resonances in the speaker basket and their transference to the magnet system. Vibrations of the magnet system generate distortions of magnetic field, where the speaker coil is moving. The effect is increasing in distortion which results in decreasing of the sound quality. To counteract of this effect in the Divine Acoustics laboratory BAD – Basket Accurate Dampening system came into being. It is a system, which gives the speaker comfortable working conditions. It lowers proportion of the vibrations transferred from the diaphragm, through the suspensions to the magnet system through the speaker basket. The accurate modification of the speaker basket – change and partial terminating of its internal parasitic resonances, results in the major improvement of the sound quality of transducers, before they are mounted into the speaker cabinet.

Electrical circuits – the crossovers

The crossover constitutes one of the most important elements of the speaker system and also the element which demands the greatest amount of work during the designing. Properly selected electrical schematic, configuration and layout of the elements on the board as well as its quality and connecting wires – all of these factors influence the final sound of the speakers set. The well-matched value of the elements forces the time and phase coherency of the transducers and influence its musicality, felt speed and punctuality of the sound. Properly configured crossover plays the key role in harmonizing of the speakers with each other and, thus, they create homogeneous entirety just as if they become a single transducer which reproduces the entire frequency spectrum. Listening tests, which were carried out, have proven the fact that making connection with the amplifier using single-wiring with the higher quality speaker cables gives better sound’s result than bi-wiring using lower quality speaker cables.

Due to that fact all Divine Acoustics' hold a single connection plugs allowing single-wiring. The crossover configuration is not just the division of the frequency response and phase arrangement of the speakers. It is also very important for the amplifier distribution of the power which is picked up by the transducers. The correct distribution of the power coming from the amplifier to the individual transducers allows gaining the significant volume of the undistorted sound with full dynamics range and simultaneously reproducing of full frequency response with very low volume. That kind of the crossover configuration facilitates driving the speakers even by the amplifiers with the minor output power. The crossovers designed by Divine Acoustics are second order passive filters. Thanks to the additional circuits, which are correcting phase and impedance for both speakers in two-way speaker system, elimination of the series and parallel resistance elements in the filter path for high frequency speaker has been made. It improves the micro dynamics and nuances of the high frequencies considerably with coincident preservation of the proper ratio to the middle frequency range.

The crossovers are made of high quality elements. All capacitances are Jantzen-Audio polypropylene capacitors, which are commonly connected into pairs containing different sounding Z-Superior, Z-Standard, Cross-Cap and Z-Silver series. Variety of used capacitors is matched during listening sessions and influence significantly to the final sound quality of the speaker system.All of used coils are made of oxygen free copper (OFC), they are accurate measured and paired. All the crossovers during the assembling are extensively verified of all values and the quality of joints. After assembling the comparison with the comparative crossover is made. It assures the repeatability and high quality of components mounted into Divine Acoustics speakers.  All joints are made using soldering alloy which contains tin and copper and it is free of lead (Pb free).

The SGP system

The crossovers of all Divine Acoustics models contain custom designed - Single Ground Point system. It assumes that all the connections related to the ground for entire electrical configuration of the speaker crossover, and also all wiring connected to the ground is gathering in one single point. It prevents to create unwanted potential differences between the elements of the electric filters. Using of single ground point considerably increases the sound quality of speaker system, enhances its transparency, micro dynamics and naturalness of the sound. Divine Acoustics products are made in a small manufacture in Poland.

Starting from the first sketch, through all design works, carpentry, upholstering, final parts assembling, to the final product all activities in Divine Acoustics workshop are made by hand.