[Main Speaker] Avantgarde Acoustic / basshorn G2 BASSHORN FACT SHEET  

BASSHORN FACT SHEET

 
THE BASS HEAVEN

The Basshorn is much more than just the ultimate bass extension to high end stereo systems. It provides the rock-solid foundation to any kind of music. It extends dramatically the dynamic spectrum and emotional impact of the Trio system. It does not only bring the lowest frequencies spectacularly, powerful and ultra-dynamic to life, but even transforms the sound quality of voices and instruments into a new class of precision and and authenticity.

The Basshorn extends the energy content and transients of the Trio to the lowest octaves. A full range horn solution which brings music to a new level of excitement – a seductive fascination like you have never heard before!

THE HIGH END MYTH

Why is the Basshorn a high end myth? Why is its nature of response so explosive, precise, natural and pure? Why is any other bass technology – even the most elaborate designs – so dramatically outperformed? Just look at it and you know why!

This mythical quality is first of all emphasised by their sheer size - which is determind by physics - and last but not least by their potential of providing for ultimate punch and clarity in the bass range.

But accomodating a hornloaded bass so far demanded a huge commitment: either by compulsory use of corners, by necessary construction work in your listening room, or by lack of deep bass (due to “reasonable” horn dimensions). Avantgarde Acoustic™succeeded in designing and engineering a highly flexible modular horn subwoofer which accomodates to various environmental and acoustical conditions.

You can decide for yourself how to configurate and where to place your Basshorn: in corners or free standing in front of a wall, as double, fourfold or sixfold Basshorn. Every module is reasonable dimensioned, thus no extensive logistics are required for transport and setup. 

The Avantgarde Acoustic™ Basshorn isn’t just another powered subwoofer, its ADRIC (Adaptive Radiation Impedance Control) amplifier technology (Patent pend.) allows for powerful and deep bass despite its relatively small horn mouth area. This ensures a convincing performance of even only 2 or 4 Basshorn modules, because every single module performs down to 18 Hz; an unparalleled performance at the given horn dimensions.

The built in crossover and ADRIC amplifier allow for a sensitive adjustment to the available satellites and to the acoustical environment.

THE SYSTEM

The Basshorn is a fully active bass system with a response of 18 to 250 Hz. Each Basshorn is driven by two powerful 12 inch long excursion drivers with 600 watts RMS. With their 185 inches squared of membrane area, the drivers are capable of displacing 31 inches of cubic air which is thrust into throat of the horn.

The sound waves are then guided through the 55 inch long expo–spherical horn and propagated into the room. The modular concept allows the user to tailor the system to different acoustical environments and allows for further upgrades by just adding another set of Basshorns, up to a maximum of 6 modules. The horn mouth area of each Basshorn module is 9 ft squared. In a 6 x Basshorn configuration this translates to 54 ft squared! 

But besides its overwhelming dimensions and impressive technical specifications, the Avantgarde Acoustic™ designers have included something really unique: the patented ADRIC-technology.

This “Active Dynamic Radiation Impedance Compensation” is a special circuit which dynamically compensates for small horn mouth dimensions and linearises the bass response below the cut-off frequency of the horn. It enables the Basshorn - even when operated only with 1 module - to achieve a bass response down to 18 hz with a horn mouth of just 9 ft squared. With its patented ADRIC circuitry the horn specialists from Avantgarde Acoustic™have managed to design the smallest full range horn subwoofer in the world.

THE ADRIC HORNSUBWOOFER

Basshorn systems are a myth and enjoy a legendary but at the same time – when they are constructed too small – an ambivalent reputation. Too small dimension will inevitably cause bouncy impedance curves and a boomy frequency response. 

To cope with this problem, the technical literature recommends using drivers with very stiff suspension, light moving mass and small rear chamber volumes. This way the resonance frequency of the driver FO is set at or above the cut-off frequency of the horn FO. 

As the driver does radiate significantly less energy below his resonance frequency reflections back into the horn are minimized. In other words the driver parameters are matched to the horn in a way, that the response for the given horn is optimized. This shows the major drawback of reactance annulling. The lowest frequency is only determined by the size of the horn. So reactance annulling improves the response but cannot make horns go lower in frequency!

Contrary to all common knowledge, Avantgarde Acoustic™´s approach purposely works without reactance annulling. Unlike the drivers used in their ADRIC basshorn systems have a low resonance frequency with relatively soft suspension. These are applied in a front loaded horn with a big rear volume behind the driver to allow for high acoustical output at low frequencies. To compensate for the inescapable impedance irregularities - caused by the resonance frequency of the driver being lower than the cutoff frequency of the horn - the Avantgarde Acoustic™ uses its patented “Active Dynamic Radiation Impedance Compensation”. The way ADRIC works is shown in the graphic. The upper chart shows the typical bumpy impedance curve caused by a driver with low resonance frequency connected to a relatively small horn. The output voltage of the ADRIC amp is shown in the chart below. At rising impedance of its load the ADRIC amplifier with negative output impedance generates an inversely proportional output voltage. It is practically the inverse of the frequency curve.

The thick black line in the next chart shows the resulting frequency curve driven with an ADRIC amplifier. The circuit linearizes the peak at the resonance frequency of the driver 1, the peak caused by back reflections at the cut-off frequency of the horn 2, the spikes caused by cabinet resonances and further room induced reflections 3. Furthermore ADRIC flattens the upper frequency response of the horn, caused by the higher inductivity of the driver at higher frequencies 5. As the motional feedback circuit of ADRIC compensates as well for all cabinet induced influences, even the frequency response below the resonance frequency of the driver is beeing linearized 4. ADRIC thus automatically compensates all waviness and ripples induced by cabinet, horn, driver and room.

The drop below the cut-off frequency of the horn is caused by the difference in sensitivity between horn and sealed enclosure. Using an active equalization with the respective filter characteristics (see lower chart) will flatten this drop. As a result all Avantgarde Acoustic™ ADRIC horn bass system will have a perfectly flat frequency response.

The proprietary ADRIC technology of Avantgarde Acoustic™ thus ensures that relative small hornsize and overwhelming low frequency extension does not necessarily exclude. It is based on our fundamental research of the electro-acoustical interdependencies of wavefronts being induced in horn funnels. The complex ADRIC circuits detect the characteristic impedance peaks and precisely compensate through ultrafast analogue feedback loops. 

THE SUBWOOFER AMPLIFIER

The integrated active HPA 106 electronics of the Basshorn consists of two powerful 250 watt amplifiers and an active frequency crossover. A forceful 540VA toroidal transformer and an energy reservoir of 120.000 μF providing ample energy reserves and dynamic headroom. Up to 1.000 Watts of class A/B amplifier power provide for sufficient reserves under any condition. The toroidal mains transformer is mechanically decoupled to prevent resonances.

In order to achieve full control to overcome the inertia of the driver mass, the HPA 106 is equipped with Avantgarde´s genuine ADRIC circuitry. These ultrafast analogue electronics compensate detect and compensate for characteristic impedance fluctuations of the bass driver voice coil - effected by small horn mouth dimensions - by a fast analogue feedback loop. As a result the Basshorn achieves an astonishingly flat frequency response down to 18 Hz! Furthermore, even at very low listening levels – when the music signal is too weak to overcome the inertia of the bass driver mass – the adaptive motional feedback circuitry will seamlessly increase its power output for a full and rich bass response.

The active crossover allows the adjustment of a number of parameters thus ensuring a very easy and fast installation of the system even in acoustically critical situations. A 3–position subsonic switch, variable settings for the input sensitivity and crossover frequencies make the HPA 106 extremely versatile. The HPA 106 can be remotely switched on/off using the 12V trigger signal.

The HPA 106 is driven via high power speaker terminals for direct connection to integrated amps, power amplifiers or receivers or alternatively via XLR terminals. The signal take–off is not only at high impedance, but is also balanced and transformer coupled. This floats the subwoofer ground, avoiding hum loops and eases connection to balanced and bridged amplifier designs.

THE SUBWOOFER DRIVER

The Basshorn is driven by two powerful 30 cm (12 inch) 600 watts (RMS) long-excursion drivers.

The 12–ND600 is the result of an extensive and intense research of every single constituent part of an electro-dynamic loudspeaker,rethinking the basics and taking care of every detail, to withstand the extreme power conditions it has been designed to work in.All this investigation is reflected in the new and innovative technologies developed by Avantgarde Acoustic™ and applied in this new transducer.

The 12–ND600 features a 4 inch voice coil with laminated former combining two different advanced technology materials to enhance the voice coil life and to ensure an optimum force transmission. A forced convection mechanism results in low power compression. This design has been optimized with the extensive use of miniature high temperature probes and real-time temperature acquisition systems, together with a thermographic camera to obtain real images of the heat distribution in the voice coil and forced convection effects.

The Double Conex Spider with its diaphragm surround and the double spider have been carefully designed with the assistance ofFinite Element calculations in order to match coherently, enabling long and controlled cone displacements.

The 12–ND600 long excursion drive unit is characterized by its extremely high efficiency and utmost power handling capabilities. The extended controlled excursion is +/– 8 mm. Exclusive neodym magnets with a special under–pole magnet topology are used to maximize the flux density in the air gap and to eliminate energy leakage of the magnetic field. The powerful neodym magnet with a very strong BL power factor and the very stiff but light membrane will ensure highest resolution and authority even with complex signals at extreme sound pressure levels.

MECHANICAL CONSTRUCTION

The enclosure of the Basshorn is made from 40 mm laminated wood material. The wavelike horn flare is machined by Avantgarde Acoustic™ from multilayer sandwich material and vacuum formed in an elaborate strain hardening process. 

The rounded shape and further internal reinforcing stabilizers reduce standing waves and ensure a rigid and non-vibrant enclosure of the Basshorn. 

WOODEN VENEERS FOR THE BASSHORN

Each Basshorn is individually manufactured to customer specifications. The wooden parts of the enclosure are available in a variety of different wooden veneers. Besides the standard Avantgarde Acoustic™ veneers - Flower Birdseye Maple, Hanami Lucent Cherrywood, Tianshan Mystic Walnut and Jacaranda Aura Rosewood - multiple other wooden veneers are available upon request. All wooden surfaces have an elegant silky matte finish.

The wavelike horn flare of the Basshorn has an elegant stainless steel finish.
basshorn-g2_fact_sheet_engl.pdf
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