Fig. 6 Displaced Speakers
The phase correction angle (
Φ
in degrees) for a known speaker displacement is given by
Φ
∆
=
⋅
°⋅
s
f
c
360
∆
s:
Speaker offset in m
c:
Speed of sound in air. (Given an air pressure of 101.3 hPa and a temperature
of 20° Celsius c is 340 m/s. The temperature coeff icient is 0.6 (m/s)/°C).
Example: You want to control a monitor with two 12’’speakers and a 2’’driver with the SP2. The 2’’
driver’s acoustical center is 0.115m behind the 12’’speaker’s acoustical center. The crossover
frequency is 1500 Hz. The necessary phase correction then amounts to
Φ =
⋅
°⋅
=
° ≈
°
0 115
360 1500
340
182
180
1
,
,64
m
s
m
s
3.1.4 Highmid attenuator
The attenuator function makes it possible to reduce the highmid gain relative to the woofer gain in
steps of 2.5 dB. This feature comes in handy if your bass speakers are less efficient than your
highmid system. The adjustment is performed by moving the red jumper to the respective position.
The attenuation is printed on the PC board (see fig. 7). The first position on the socket corresponds
to 0 dB.
