Technology
Drivers
The M2 OMEGA midrange driver is the core component of the DUO
MEZZO. Walking in the footsteps of the exemplar TRIO OMEGA midrange,
it is equipped with a high impedance 18 ohm voice coil, thus significantly
increasing the control of the amplifier over the membrane movement.
To obtain maximum efficiency Avantgarde Acoustic dispenses with
the usual copper insert of the magnet core, thus reducing the air
gap width and increasing the magnetic field force. The magnet is
composed of rare ALNICO material, which provides high flux density
and a homogeneous magnetic field inside the air gap.
The M2 OMEGA's membrane surface is coated by 'Velours Damping
Effect' (VDE) fibres. The resulting 'furry' surface significantly
reduces resonances of the cone material and absorbes unwanted harmonic
distortions. The M2 OMEGA's frequency range (on the SH6704 horn)
starts at 170 Hz. A specially customized membrane dome provides
for phase coherent and ultra linear radiation of the M2 OMEGA into
the horn throat.
The CDC system automatically limits the frequency range to 2000
Hz. Thus the M2 OMEGA can be connected without any passive crossover
parts - a typical Avantgarde Acoustic feature! The voice coil of
the M2 OMEGA receives a pure and undistorted signal from the amplifier.
No phase shifting crossover parts, just the speaker cables are
between the amplifier and the M1 OMEGA!
The tweeter of the META MEZZO is a variant of the reference tweeter
of the TRIO OMEGA. This H2 OMEGA features a kapton voice coil former,
a special winding geometry of the voice coil, a minimized air gap
and an ultra low mass diaphragm. A huge 3 kg magnet creates a strong
magnetic field that provides for detailed and exact reproduction
even of the most complex signals. Theoretically the H2 OMEGA covers
a frequency range down to 900 Hz, but the acoustical range only
starts at 2000 Hz, thus providing for high power handling capabilities
and big dynamic headroom.
CPC crossover
The correct acoustical coupling of the H2 OMEGA tweeter requires
a 12 dB/oct filtering. The necessary capacitor, which cuts off
low frequencies, is the potentially weakest part of every passive
crossover design. Every time the music signal crosses the zero
line, changing from positive to negative values and vice versa,
the electric field within the capacitor's dielectric is inverted.
This permanent inversion and 'loading and reloading' causes a so-called
'Dielectric Memory Effect', creating zero-crossing distortions
which are the more influential the higher the transmitted frequencies
are.
To avoid the permanent inversion of the electric field, Avantgarde
Acoustic developped a special 3-way conductor capacitor. By impressing
a high biasing voltage to the specially connected conductors, the
electric field becomes fixed in one direction, thus biasing the
capacitor. The electric field now keeps its orientation and is
only varied by the music signal, not 'flipping' directions any
more.
The necessary DC bias voltage is created by the proprietary 'Capacitor
Polarisation Circuit' (patent pend.) of Avantgarde Acoustic. A
transformer couples the CPC circuitry to the music signal, then
a diode network transforms the biasing voltage up to 100 Volts.
Within just a few seconds the bias voltage has built up and the
CPC capacitor reaches optimal performance. Additionally there is
even a protection circuit which avoids over voltages.
The CPC cpacitor features ultra low distortion levels, resulting
in a significantly increased accuracy when processing complex high
frequency signals and in unrivaled micro dynamics.
ADRIC hornbass
Hornbass designs have a legendary, but likewise ambivalent, reputation.
Because sizing a small horn mouth may cause droning and booming
resonances at certain frequencies. That's where Avantgarde Acoustic's
unique ADRIC circuit (patent pend.) comes in. It detects and compensates
for characteristic impedance fluctuations of the bass driver voice
coil - effected by small horn mouth dimensions - by a fast analogue
feedback loop.
Due to ADRIC (adaptive dynamic radiation impedance control) technology,
Avantgarde Acoustic can design bass horns which are able to reproduce
powerful depp bass (down to 18 Hz) with horn mouth areas smaller
than 1 sqm (instead of 6-7 sqm of non-ADRIC designs). Thus ADRIC
technology is essential for accommodating a horn bass to the DUO
MEZZO cabinet.
Each DUO MEZZO bass module features 2 x 300 mm high performance-long
excursion drivers, powered by a pair of ADRIC amplifiers. Additionally
the input section features an active crossover section. Up to 1000
Watts of class A/B amplifier power provide for sufficient reserves
under any condition. The big toroidal mains transformer of the
amplifier module is mechanically decoupled to prevent resonances.
The amplifier modules are equipped with WBT input terminals, alternatively
line signals can be fed via an XLR socket.
The input board of the bass features an input level attenuator.
The crossover frequency towards the midrange is precisely adjustable
in 3 different ranges. A 3-position subsonic filter switch and
a 12 V DC trigger input for remote ON/OFF switching complete the
list of useful functions.
Product design
The DUO MEZZO's exterior has been designed by the Swiss designers
Tobias Adami and Hannes Wettstein from zed. of Zurich. The narrowing
footprint of the cabinet and the high-quality wood surface resembles
a classical instrument. The almost minimalistic style of the Swiss
designers gives the DUO MEZZO a straight and timeless appearance. |
