
User's Manual
KLING & FREITAG GMBH ©2001 5
Speaker System SW 115D-XO
3. „Passive“ (XO ON) and „Active Operations“ (XO OFF)
The switchable low pass filter (XO) enables the SW 115D-XO to operate in passive mode as well as in
active mode when used with a mid-high system.
The switch for these operating modes is found on the connecting terminal on the back side of the
SW 115D-XO.
The passive operating mode is easy to run and cost-effective. Mid-high systems with one power ampli-
fier can be operated in conjunction with the SW 115D without using an additional crossover or con-
troller. In this mode of operation, the SW 115D–XO is controlled via the built-in low pass filter and can
be operated up to approx. 120 Hz.
For passive operations, connect the output of the power amplifier with the input socket of the SW
115D-XO. Then connect the output socket of the subwoofers with the input socket of the mid-high
system. The switch on the connecting terminal must be on “PASSIVE” (XO OFF).
Limitations of Passive Operations:
−During passive operations, it is not possible to adjust the level of the subwoofer separately.
−During passive operations, the mid-high systems also receive the low-frequency signal and are,
therefore, subject to higher strain.
During active operations, the audio signal is separated into a bass and a mid-high signal before it
reaches the power amplifier. This is done by a controller (optimally, a K&F C2 Controller) or an elec-
tronic crossover. The bass as well as the mid-high range each require a separate power amplifier.
For active operations, the switch on the connecting terminal of the woofer must be in the ACTIVE po-
sition (XO OFF). By doing so, an internal passive crossover is switched off.
The SW 115D-XO is an ideal supplement for active operations of all K&F full-range systems.
For an optimal acoustic coupling of the SW 115D-XO to an appropriate full-range system, the C2 Con-
troller must be equipped with a modular SW 115D plug-in card and a plug-in card for the selected full-
range system.
The C2 Controller adapts the phase and time alignment of the various full-range systems to match
those of the subwoofer systems. By using carefully selected modular filter cards (EQ), the C2 Controller
minimizes the risk of feedback and optimizes the frequency range of the given speaker systems. Fur-
ther connecting instructions can be found in the documentation of your electronic crossover or your
(C2) Controller.
The advantages of active operations:
−Possibility to separately adjust the level of the subwoofer.
−The mid-high systems do not receive any low-frequency signals and are not as strained.
−While taking the various mid-high systems, the crossover of the total system can be optimized
application-specifically.
−The C2 Controller optimizes the operating safety through special limiters.
Passive Operations (XO ON):
Example:
2-way passive operations with par-
allel tops CA 1201 and 1 x 2 channel
power amplifier.
Active Operations (XO OFF):
Example:
2-way active operations with Tops CA
1201. Separated by the C2 Controller
and optimally controlled tops and sub-
woofer connected to 2 power amplifi-
ers.