Technology
Drivers
Vastly benefitting from the experiences with the original DUO
design, the OMEGA drivers of the GROSSO were perfectly customized
for the DUO horns, thus eliminating the need for complex passive
frequency filters in the signal path.
The M2-OMEGA midrange driver was specially developed for the DUO
OMEGA midrange horn. The generously dimensioned magnetic structure
of the 170 mm (7 in) cone, provides an extended efficiency as well
as offering very high power handling at long excursions. This way
the M2-OMEGA has a very low cut-off frequency of 170 hz which allows
for an integration with the subwoofer without any passive crossovers.
The sound characteristics of the Kevlar diaphragm is optimized
by a special coating, providing excellent resonance damping. This
VDE (Velours Damping Effect) is achieved by microscopic fibres,
covering the entire surface of the cone. A proprietary leight-weight
4” paper dome ensures that the soundwaves entering the midrange
horn are in phase and cover the required extended bandwidth.
The CDC (Controlled Dispersion Characterietics) system features
a controlled roll-off at 2,000 Hz and consequently allows the operation
of the M2-OMEGA without any degrading filter components in the
signal path.
The H2-OMEGA tweeter is a reduced sensitivity version of our reference
TRIO OMEGA tweeter H3-OMEGA. This exceptional driver combines the
smoothness of an electrostatic driver and the power of a strong
1 inch horn driver. The mere force of the 3 kg (6.5 lb) magnet
on the voice coil guarantees 100% detail and precision even at
low volume levels, and provides the GROSSO with compression-free
sound reproduction even at extreme sound pressure levels.
With the spherical horn SH1801 the H2-OMEGA offers an ultra wide
bandwidth down to 900 Hz. Due to the passive crossover point at
2,000 Hz we achieve a wonderful smooth sound with incredible headroom
More details and information about the principles of horn and
driver design can be found under THEORY.
Subwoofer
The GROSSO is supplied with the active subwoofer SUB231-G, which
is driven by two powerful 30 cm (12 inch) 600 watts (RMS) long-excursion
drivers.
The integrated active electronics consists of 2 (1 per driver)
powerful 250 watt amplifiers and an active frequency crossover.
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.
The SUB231-G is an actively controlled subwoofer. A real-time
feedback loop not only eliminates deviations of the amp itself,
but also the deviations of the drivers. As result the SUB231-G
achieves flat frequency response down to 18 Hz!
The SUB231-G is fed via high power WBT 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 enclosure of the SUB231-G is constructed from 1.2" MDF
(30mm). Designed with a centrally located reinforcing stabilizer,
the box construction is very rigid, avoiding resonances.
Further technical details of the SUB231 can be downloaded in the
SERVICE section of this website.
Mechanical construction
The midrange is mounted into circular housing tubes. A three pillar
steel-tube frame is used to support the midrange horn with chrome
screws on lateral fixtures. Rubber elements between frame rails
and subwoofer enclosure provide for efficient vibration control.
The tweeter unit occupies a specially designed sealed enclosure
in the top part of the subwoofer. The subwoofer is equipped with
four M8 inserts, convenient for padded feet or spikes.
Finishes
The standard version of the GROSSO comes with various metallic
lacquer finishes for the horns. The circular housing tubes and
the three pillar steel tube frame is powder coated in elegant black.
The rear-covers and the subwoofer enclosure are coated in high
quality NEXTEL finish. Special designs are available upon request. |
The
successful introduction of the DUO OMEGA model inspired the Avantgarce
Acoustic engineers to develop a bigger subwoofer unit for the DUO
OMEGA line of speakers, complementing the SUB225 standard subwoofers.
The challenge was not only to offer improved bass and low midrange
performance, but also to still meet the classical DUO OMEGA appearance.
By incorporating the tweeter into the subwoofer cabinet, the resulting
SUB231-G subwoofer achieves this goal perfectly, finally creating
the DUO GROSSO model.