Instruction manual

A prime design point of the 701 is that it is
free-standing. This makes it possible easily
to remove the unit in the event of damage
etc., and service being required, thus avoid-
ing the transportation of entire heavy and
bulky system.
Crossover and Filter Unit
The 500 Hz. crossover frequency between
the DW13/5 bass unit and the 701 electro-
static unit ensures that both these transducer
elements operate over their optimum fre-
quency ranges. Care has been taken in the
design of the low-pass section of the filter
to ensure that maximum amplifier damping
may be transferred to the bass unit by the
use of heavy gauge copper in the series in-
ductor, over a ferrite core. In addition, an
impedance- and level-controlling transformer
forms a part of the bass unit filter.
The power supply and high-pass filter for
the 701 electrostatic unit is solidly and
safely housed in a steel case. The mains lead
is captive, for safety.
Cabinet
The cabinet is constructed of 25mm chip-
board; in the case of the "Continental"
version, the curved front formed from 19mm
plywood. The grille materials (earthed metal,
front and rear for the electrostatic) have
been chosen to give minimal deterioration
of the acoustic performance.
The "Standard" version of the cabinet is
available in teak or walnut veneers and a
choice of walnut veneer or satin white finish
for the "Continentals."
Acoustic Loading
The acoustic loading for the bass drive unit
is of the "infinite baffle" type, synthetic
damping material being used to achieve
optimum system "Q". A resonance-control-
ling removable pad is fitted to the rear of
the electrostatic.
Sensitivity
17 watts into nominal impedance required
to produce a sound level of 95 dB. at one
metre at 400 Hz
Power Handling
The DM70 is suitable for high quality amp-
lifiers with true RMS outputs of between
25 and 100 watts, with double fuse pro-
tection on C and CA versions.
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Electrostatic Unit model 701