JB Systems D2 Series Operation Manual page 5

ENGLISH
16. BRIDGE SPEAKON OUTPUT: use this Speakon
mode. Refer to points 5 and 12 for more information. Wiring of this connector is as follows:
 POS(+) = Speakon connector PIN1+ and PIN2+
 NEG(-) = Speakon connector PIN1- and PIN2-
17. CH1 FILTER CONTROL: used to adjust the crossover frequency of the internal crossover for channel1.
You can adjust the frequency between 90Hz and 250Hz: perfect to make an active system based on a
subwoofer + top cabinet! For most subwoofer applications a crossover point between 90Hz and 150Hz is
OK, however while listening and comparing you will easily find the optimal settings for your system.
18. CH1 FILTER SWITCH: used to set the desired filter for channel1: high pass, low pass or no filter:
 High pass filter (HPF): use this filter when you want to connect a small top cabinet to the output
of channel1. See the chapter "How to use" for more information.
 Low pass filter (LPF): use this filter when you want to connect a subwoofer cabinet to the output
of channel1. See the chapter "How to use" for more information.
 No filter: use this option if you want to connect a normal full range speaker cabinet to channel1,
this is the most common user mode.
19. CH2 FILTER CONTROL: Exactly the same function as described in number 17 but now for channel 2.
20. CH2 FILTER SWITCH: Exactly the same function as described in number 18 but now for channel 2.
21. GROUND LIFT switch: In some cases nasty hum noises can occur due to ground loops in your setup.
Setting the Ground lift switch to the position "lift" breaks the ground loop between the amplifier and the
chassis grounds of various other components in your setup. As a result the hum noises disappear.
22. RESET button: this amplifier uses an automatic fuse. When the fuse is blown, simply press the button to
rearm it.
23. MAINS input: When all audio cables are connected, you can connect this cable to mains outlet.
HOW TO USE
Normal use in stereo mode
Will be used in most cases for a simple setup with 2 speaker cabinets.
 Connect the audio signal to both inputs (11)
 Connect the speaker cabinets to both outputs (15)
 Put both filter switches (18) and (20) to "no filter"
 Put the mode switch (13) to stereo
 Close the gain controls (2)
 Switch the amplifier on (9)
 Open the gain controls (2) to the desired level.
Used with the crossover filters to obtain an active stereo system
Please note that when used in an active setup you need 2 amplifiers to obtain a stereo system. There are 2
different options to connect the amplifiers:
Option1 – one amplifier per side for high and low outputs
In this setup we use channel1 for the top cabinet and channel2 for the subwoofer on both amplifiers.
We use one amplifier for the left channel and one amplifier for the right channel .
 Connect the audio signal only to the channel1 input (11)
 Put the mode switch (13) to mono
 Connect the top cabinet to the output
(15) of channel1
 Connect the subwoofer to the output
(15) of channel2
 Put the filter switch of channel1 (18) to
"high pass filter"
 Adjust the crossover frequency of
channel1 (17)
 Put the filter switch of channel2 (20) to
"low pass filter"
 Adjust the crossover frequency of channel2 (19)
 Close the gain controls (2)
 Switch the amplifier on (9)
 Open the gain controls (2) to the desired levels so you have a nice balance between the top
cabinet and the subwoofer.
JB SYSTEMS
®
OPERATION MANUAL
®
connector to connect your speaker cabinet in bridge
5/42 D2-900 ~ D2-1200 ~ D2-1500
ENGLISH
 Further adjust the crossover points of the filters (normally the crossover points of both channels
should be equal)
Remark: if your top cabinets can support low frequencies (example: top cabinets based on 15" or
2x15" woofers), you can set channel1 to "no filter". The top cabinets are not filtered which results in
more punch for the low frequencies.
Option2 – one amplifier for top cabinets and one amplifier for subwoofers
In this setup we use both channels of amplifier A for the top cabinets and both channels of amplifier
B for the subwoofer(s). Both amplifiers receive a normal stereo audio signal.
 Connect the stereo audio signal to the inputs of both amplifiers (use a short XLR-cable to daisy
chain the inputs of both amplifiers)
 Put the mode switch of both amplifiers (13) to stereo
 Connect the top cabinets to the outputs (15) of amplifier A
 Connect the subwoofer(s) to the outputs (15) of amplifier B
 Put both filter switches on amplifier A to "high pass filter"
 Adjust the crossover frequency (17)
for both channels of amplifier A
 Put both filter switches on amplifier B
to "low pass filter"
 Adjust the crossover frequency (17)
for both channels of amplifier B
 Close the gain controls (2) on both
amplifiers
 Switch both amplifiers on (9)
 Open the gain controls (2) of amplifier
A to the desired level
 Open the gain controls (2) of amplifier B until have a nice balance between the top cabinets and
the subwoofer(s).
 Further adjust the crossover points on both amplifiers
Remark: if you only use one powerful subwoofer, you can switch amplifier B to bridge mode and use
the bridge output to connect the subwoofer. In this case only the controls of channel1 should be
used.
Used in bridge mode, without filters
In this case the amplifier has only one mono output but with a much higher output power.
 Connect the audio signal to the input of channel1 (11)
 Connect the speaker cabinet to the bridge output (16)
 Put both filter switches (18) and (20) to "no filter"
 Put the mode switch (13) to bridge
 Close the gain controls (2)
 Switch the amplifier on (9)
 Open the gain control of channel1 (2) to the desired level. (the gain
control of channel2 is not used)
Used in bridge mode, with filters
Below we explain how to connect a powerful subwoofer.
 Connect the audio signal to the input of channel1 (11)
 Connect the subwoofer to the bridge output (16)
 Put the filter switch of channel1 (18) to "low pass filter"
 Adjust the crossover frequency of channel1 (17)
 Put the mode switch (13) to bridge
 Close the gain controls (2)
 Switch the amplifier on (9)
 Open the gain control of channel1 (2) to the desired level. (the gain control of channel2 is not used)
JB SYSTEMS
®
OPERATION MANUAL
6/42 D2-900 ~ D2-1200 ~ D2-1500