Technology
Drivers
Our challenge was to design custom-made driver systems, which
perfectly integrate with the DUO horns and thus eliminating the
need of passive frequency filters in the signal path.
The M2 midrange driver was specially developed for the DUO. 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 has a very
low cut-off frequency of 170 hz which allows for an integration
with the subwoofer without any passive crossovers.
The resonance charcteristic of the 100 mm (4 in) dome is optimized
by a special coating at the backside of the dome. The design of
the dome ensures the soundwaves entering the midrange horn are
in phase and cover the required extended bandwidth.
The CDC system features a controlled roll-off at 2,000 Hz and
consequently allows the operation of the M2 without any degrading
filter components in the signal path.
The H2 tweeter is a reduced sensitivity version of our reference
tweeter H3. The exceptional driver H2 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 DUO with compression-free sound reproduction even at extreme
sound pressure levels.
With the spherical horn SH1801 the H2 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 DUO is supplied with the active subwoofer SUB225, which is
driven by two powerful 25 cm (10 inch) long-excursion drivers.
The integrated active electronics consists of a powerful 250 watt
class A/B amplifier 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 SUB225 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 SUB225 achieves an
astonishingly flat frequency response down to 18 Hz!
The SUB225 is driven 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 SUB225 is constructed in axial symmetry with
1.2" MDF (30mm). Designed with a centrally located reinforcing
stabilizer, the box construction is very rigid, avoiding resonances.
Further technical details of the SUB225 can be downloaded in the
SERVICE section of this website.
Mechanical construction (Patent pending)
Both, the midrange as well as the tweeter horn are mounted into
circular housing tubes. A three pillar steel-tube frame is used
to support the horns with chrome screws on lateral fixtures. As
the latter shows various mounting locations, the midrange and the
high-frequency-horn can be installed at various heights. This enables
optimal positioning of the system to different listening positions.
As the entire loudspeaker system is placed on three self-aligning
feet, the sub-woofer is freely-suspended above the ground. This
free floating design enables an ideal decoupling from the floor
boundary. If necessary the subwoofer can be further de-coupled
with spikes.
Finishes
The standard version of the DUO 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. |
