System know-how

Correct timing is an essential criterion for an ideal loudspeaker. The human ear reacts very sensitively to the timing (phase) of acoustic signals. This has always been, and still is, crucial for survival, be it in the face of predators or automobiles: precise hearing - what, when, and wherefrom.

For this purpose the human brain locates the direction and the distance of a sound by means of the interaural time difference of the perceived signal between the left and right ears.

The requirements for developing a time-aligned loudspeaker are considerable and complex. Treble drivers react considerably faster to an impulse than heavier midrange and bass drivers. Likewise time response varies between the drivers and the listening position depending on listening height and listening distance.

ASCENDO´s VTA technology makes it possible to adjust the speaker to the individual listening position by shifting the treble unit. This results in a truly time-aligned signal at any listening position. Listeners have described this perfect adjustment to the listening position as: “the sound locks in“.

In his article “Das Wunder des Hörens (The Miracle of Listening)“, Andreas Günther describes the importance of the criterion of correct timing even for relaxed listening:

“Listening becomes work. What was vital for cave-dwellers is equally decisive in the Highend-Process: if we cannot locate correctly the direction of a sound signal, if the sound engineers have perhaps even toyed with the phase, our brain starts struggling. Listening becomes hard work, causes stress.“

With ASCENDO transducers you avoid this stress!

SASB is ASCENDO´s bass / midrange-technology, which has found its way from fundamental research into the world of audio.

The development of this advanced technology was financially supported by the Federal Ministry of Research and Technology. It contributes decisively to the perfect timing and great signal integrity of the System series loudspeakers, because SASB combines fast transient response and decay, perfect group decay (timing), with a punchy bass that is both dynamic and reaching far down. This combination of performance and perfect timing is impossible to achieve with classic speaker construction principles, such as bass-reflex loading. Thus SASB is one of the key-technologies of the ideal loudspeaker.

How Does SASB Work?
Several drivers are in charge of the bass / midrange section: a forward-firing midrange driver, mounted in the baffle, and an invisible high-performance woofer that operates horizontally inside the cabinet.

The external driver has its own, hermetically sealed volume chamber. The internal driver operates both into a ventilated volume, the reflex chamber, and within a closed volume, the compression chamber. This chamber provides the constant inner damping. In this way the interior driver constitutes a bandpass characteristic with different slew rates in both directions (“semi-symmetrical“). In a second step the two resonance frequencies and the impedance minima of both chassis are synchronized, so that they complement each other perfectly, and simultaneously dampen critical resonances of the external driver.

Magnetostats are renowned for their wonderfully “silky“ treble reproduction.

More than 20 years of experience with this tweeter-technology have enabled ASCENDO to perfect the big magnetostatic tweeters with regard to the particularly high requirements of the ideal loudspeaker. In this context a multistage process, as developed by ASCENDO, is employed.

Optimizing the tweeters calls for great skill and long-standing experience. All magnetostats are repeatedly measured and tested during the process of optimisation. Based on these measurements the drivers are then selected and matched in pairs. The approved drivers for System M5 and System Z5 are undoubtedly some of the best tweeters available worldwide.

The loudspeakers of the System series are characterized by their modular construction with strictly separate bass/midrange and treble units. These autonomous units each have their own drivers, terminals (binding posts), crossovers, cables and cabinets. Only materials which are hardly prone to resonances are used.

The superior mechanical and electronic decoupling of the treble unit from the bass/ midrange unit is a decisive advantage of this elaborate construction.

With its strictly modular construction a possible broadband transmission of mechanical vibration from the energetically highly charged bass/midrange section to the sensitive treble unit is prevented effectively. A comparably effective isolation of the treble unit can neither be achieved in a single cabinet for all drivers nor in an assembly of rigidly mounted single cabinets.

This already superior kind of decoupling is further perfected with ASCENDO´s flagship System M5S. It has an additional metal stand module made of high-grade polished stainless steel. The bass/midrange unit is coupled with the stand module - filled with compressed quartz dust - at three defined points. This design principle, also used in the design of bridges, provides effective mechanical isolation between the speaker and the stand module. Two special cones support the bottom front corners of the bass/midrange module above the base. At the back the module is coupled with the vertical riser of the stand by means of a spiked cone, made of nickel-plated brass. Extending horizontally from the riser is a massive stainless steel cylinder, with a diameter of 8 cm, for supporting the treble unit.

All materials differ in their excitation frequency. The resonance frequency of the massive steel cylinder, for example, is very low, and differs considerably from the resonance frequencies of the other modules. The SE models have additional special isolation units, together with the quartz dust filling of the stand module base.

The high-performance drivers and coils of the bass/midrange section generate strong magnetic fields. The treble crossover is mounted in a separate casing, far away from the drivers and coils of the bass/midrange unit, to prevent interferences with its highly sensitive components.

The sonic advantages of completely autonomous and decoupled units to classic designs of cabinets are significant: faster response behaviour, greater transparency and detail resolution, more structured bass reproduction and consistent treble quality, even at increasing volume levels.

Only very few listening rooms have solid, vibration-free floors. As a result loudspeakers can generate structure-borne sound at the floor surface. The floor turns into a secondary acoustic source. This common effect can result in a lack of transparency and resolution, or even a muffled, diffuse sound image. The ASCENDO System M5, System Z5 and System F-C MKII are decoupled from the floor by means of a combination of stainless steel / ceramic decouplers and special bases.

While the base provides a broadband interception of mechanical vibration, the stainless steel / ceramic decouplers dissipate the stored energy of the transducer in the attenuation-optimized base.

C-Decoupling increases the loudspeaker´s response behaviour and results in a more open and differentiated sound image.

Our RMR internal wiring, developed together with High End Masterclass, reduces electronic modulation from the speaker back to the amplifier. Several differing cable bundles consisting of single, top quality silver and copper cables are manufactured for each driver. The cable bundles are optimized for the specific properties of the treble, midrange and bass drivers, and have a large diameter each. The manufacturing effort for such a cable harness is enormous. So more than 90 meters of single cables are needed for a set of cables for a pair of System M speakers.

The connection terminal is fitted with Furutech Rhodium binding posts. These plugs are definitely the best binding posts worldwide. For the connection of the Furutech plugs with the RMR cable harness a soldering process is used that has been developed in cooperation with the cable specialists of High End Masterclass. Though time-consuming this procedure guarantees perfect solder joints, without damaging the heat-sensitive Rhodium of the Furutech binding posts. . RMR interior wiring and Furutech Rhodium binding posts reduce the stored energy in the loudspeaker and the electronic modulation feedback with the amplifier. The sound image becomes more open and more differentiated.

In addition the terminals with their connecting cables to the crossover are very briefly exposed to extreme heat. This elaborate procedure gives the terminals with their soldered on cables their defined directionality from the terminal to the crossover.

SE internal wiring is even more complex than RMR internal wiring. For each driver further cable bundles, perfected for the characteristics of the drivers, are used. Here the Furutech-Rhodium-Carbon binding posts are connected with the cable harness by means of an elaborate soldering process. This procedure, developed in cooperation with High End Masterclass, allows for a perfect solder connection - even with large cable diameters - without damaging the very heat-sensitive Rhodium. Furutech-Rhodium-Carbon binding posts are considered the best of their kind worldwide.

After that the single cable bundles, including the already connected Rhodium-Carbon binding posts, are very briefly exposed to extreme heat. As a result of this process the cables and binding posts get their defined directionality.

These terminals and SE-internal wiring result in a further improvement of the loudspeakers. Micro-dynamics across the whole frequency range are enhanced. The rise of tones is perceived earlier and their decay considerably longer. As a result the SE models sound even more realistic.

The functional-selective design of the crossovers is based on first-degree frame filters with a constant voltage core. This integrated complex filter design makes for the separation efficiency of high order filters, and simultaneously for the homogeneous group delay of first-degree filters. These components, together with SASB, are the key factor of the very good group delay and the considerable dynamic reserves of the system.

It goes without saying that only selected high-performance components are employed. This highly complex, interconnected and interdependent circuitry is one of the key factors why ASCENDO loudspeakers come so close to the ideal transducer.

Steep higher order filters are a necessity for broadband, dynamic, high-resolution speakers with a great power handling. These filters make sure that the drivers employed run within their ideal frequency range. Steep filters, however, invert the phase, which is counterproductive to the ideal of the time coherent loudspeaker. Low order filters (6dB / octave) may be time correct, but are deficient in separation efficiency. The employed drivers do not run within their ideal frequency range over long stretches.

The special ASCENDO filter design makes possible a very great filter efficiency without inverting the phase (time correct). This is absolutely unique.

The synergy between the SASB and the special filter design allows for the lossless transmission of very low-level sounds. Even at low listening volumes low and fundamental tones can be heard, and all signals are transmitted dynamically and with great resolution.

The sonic characteristics of the System Series speakers do not change with decreasing volume levels. As a result a concert grand piano is not reduced to a piano or a Pavarotti to a performing lightweight. The System Series speakers are hence predestined to enjoying music at low, but lossless, volume levels.

The switchable rear TOS unit produces a wonderfully airy and spatial sound, even with the loudspeaker positioned close to a wall. Sounds decay perceptibly longer, and the spatial impression becomes even more authentic. In addition TOS makes spatial listening possible even when sitting in the sweet spot.

BACYC is a technique, developed by ASCENDO, to optimize room dispersion. The BACYC dispersion characteristic of two differently weighted cylindrical waves minimizes room dependent acoustical influences.

System Series loudspeakers are versatile in their adaptability to different kinds of room acoustics.

The innner woofer operates within a closed volume. Thus Its mechanical damping is constant. This allows for a variation of the length of the reflex tube. The shorter the reflex tube the more pressure the System Series speakers generate, and vice versa.

So the bass pressure level can be perfectly adapted to the particular listening environment or to individual preference. If one loudspeaker is positioned in a room corner, and the other in an open space their room response differs considerably in the bass and fundamental range. This results in unstable stereo imaging.

Reflex tubes of differing length make it possible to create a uniform pressure level of both loudspeakers. Three-dimensionality is greatly improved.

Standing waves are a frequent room acoustic induced problem. A very loud and slowly decaying bass reproduction is the result. This interferes with the midrange spectrum, rendering the overall sound indifferent and muffled. This problem is solved by using long reflex tubes.

The cables developed in collaboration with the cable specialists of High End Masterclass perfectly match ASCENDO transducers. Being of extremely high quality and meticulously manufactured, and fitted with premium parts like Furutech Rhodium connectors, these cables sound natural and well-balanced. Their bass reproduction is structured and punchy, without being overemphasized. Treble reproduction is silky and never too bright. The gain of transparency and resolution is immediately audible, too. Many music-lovers describe the move to these fantastically manufactured cables as follows: an imaginary curtain in front of the loudspeakers has been removed. Everything sounds more open, more detailed and noticeably more dynamic!

Special elaborate soldering processes are employed in the manufacture of the cables. Manufacturing cables of this quality needs longstanding experience and is extremely timeconsuming. As a finishing touch all cables with their connectors are very briefly exposed to extreme heat. As a result of this special process the cables and their connectors get their defined directionality. The improvement in sound reproduction is immediately audible.

Though perfectly matched to the terminals of ASCENDO loudspeakers, the cables also sound fantastic with speakers of different makes. Speaker, jumper, interconnect and power cables are available in different quality grades.