Distance
From The
Rear
Wall:
Since the Spectra is a
dipole loudspeaker (producing soundfrom bothsides)
placing the speaker too cbse to the rear wall will yield
reduced bass output, due
to rear-wave cancelations.
A minimum speaker-to-rear wall distance of 3 feet (1
meter) is recommended,
as
measured from the rear
center of the array perpendiilartothewall. Note also
that the distance to the rear wall can be
used
in some
situations to adjust the
low
frequency balance in the
room.
Distance
From
The Side
Walls:
Some space is desir-
able from the side walls, but the asymmetric nature of
Spectra's horizontal high frequency radiation makes
side wall reflection less of a problem than with most
otherspeakers. Aspacingof
1
foot (30 cm) is the mini-
mum recommended distance from the side wall
to the
array's outer edge. In wide rooms, of course, this
distance may be much greater.
Toe-In
And Distance Between
Speakers:
There are
numerous combinations of toe-in angle and distance
between speakers that will yield excellent sonic per-
formance. In most situations, the distance between
speakersshouldberwghlyequaltothedistancefrom
each speaker to the listening position. The speakers
should also be toed-in at an angle
so that they more-
or-less face the listening position.
The
Area
Between The Speakers:
This
area
should
be
kept clear of major obstructions to airflow
if
optimum
imaging
is to be achieved. The size, shape, and
material of any objects placed between the speakers
will determnie theextentof any negative effects on im-
aging.
ADDITIONAL INFORMATION
Specifications
PHYSICAL DIMENSIONS:
Height
........................................
67.5" (171.5
cn)
Width
.........................................
16'
(40.6
cm)
Array Depth
...............................
3"
(7.6
cn)
Woofer Depth
............................
16.75" (42.5 cn)
RECOMMENDED AMPLIFIER POWER:
75
-
100 watts perchannel or greater (based on
8
ohm
amplifier rating). See further discussion under
"Amplifier Recommendations".
BIAS POWER SUPPLY CONSUMPTION:
Less than
10
watts.
EFFICIENCY 88
dB SPL'
(400 Hz,
1
watt into
8
ohms equivalent at one meter,
extrapolated from measurements taken at
10
watts
into
8
ohms equivalent, measured at a distance of
3.16
meters.)
IMPEDANCE:
Typically greater than
6
ohms, mini-
mum of
2
ohms at high frequencies (see graph).
FREQUENCY RESPONSE:
-3 dB
at
30 Hz, -3 dB at
19
kHz ("High" setting)
CROSSOVERS:
Electrostat:
Woofer:
250
Hz.
-6
dB per Octave electrical,
-12
dB effective acoustic
rolloff.
250
Hz. modified
-1
2
dB per octave,
internal phase reversal.
14
13
