JBL Professional MPC-XU owner manual Bypassing the filters, Programming the low-passfilter

Bypassing the filters

To completely bypass the filter circuitry of a channel, set the jumpers on both Jx01 and Jx02 across pins 1 and 2, which are the upper two pins on their headers (see Figure 6). Note: If you neglect to place jumpers on either header, no signal will pass on that channel.

Figure 6

Switch Sx01 in	Switch Sx01 in	Resistor network
"× 1" position	"× 10" position	in RNx02
80 Hz	800 Hz	120K
100 Hz	1000 Hz	82K
120 Hz	1200 Hz	68K
160 Hz	1600 Hz	56K
200 Hz	2000 Hz	47K
250 Hz	2500 Hz	33K
500 Hz	5000 Hz	18K
800 Hz	8000 Hz	12K
1600 Hz	16000 Hz	5.6K
2000 Hz	20000 Hz	4.7K

Low-pass filter frequency table

Programming the low-pass filter

Bypass/enable header—To use the low-pass filter, set the jumper on Jx01 across pins 2 and 3, which are the lower two pins on their header. But if you do not wish to use the low-pass filter and want to bypass it instead, set the jumper across pins 1 and 2.

Setting frequency—To set the corner frequency (at which the output is 6 dB down) of the low-pass filter section, choose the appropriate resistor network value and switch setting for RNx02 and Sx01, respec- tively. (Sx01 is a ×10 range switch. In its upper position, the frequency range is ×10; in the lower it is ×1.) Use the low-pass table to select the right combination. See the appendix of this manual for keys to identifying the correct resistor network.

Inserting the resistor network—If there is a resistor network already installed in the socket, carefully pull it straight out. Insert the pins of the new resistor network into the socket holes and carefully press the network into the socket. Be careful to avoid bending the pins of the resistor network. Orientation of the resistor network is unimportant, as long as all 8 pins are well seated in the socket.

Switch Sx02 in	Switch Sx02 in	Resistor network
"× 1" position	"× 10" position	in RNx04
20 Hz	200 Hz	120K
30 Hz	300 Hz	82K
40 Hz	400 Hz	56K
50 Hz	500 Hz	47K
80 Hz	800 Hz	27K
100 Hz	1000 Hz	22K
120 Hz	1200 Hz	20K
150 Hz	1500 Hz	15K
200 Hz	2000 Hz	12K
400 Hz	4000 Hz	5.6K
500 Hz	5000 Hz	4.7K
800 Hz	8000 Hz	2.7K

High-pass filter frequency table

Programming the high-pass filter

Bypass/enable header—To use either the high-pass filter or the constant-directivity horn equalization, or both, set the jumper on Jx02 across pins 2 and 3, which are the lower two pins on their header. But if you do not wish to use either one of these functions and want to bypass them, then set the jumper across pins 1 and 2.

Setting frequency—To set the corner frequency (at which the output is 6 dB down) of the high-pass filter section, choose the appropriate resistor network value and switch setting the RNx04 and Sx02, respectively. (Sx02 is a ×10 range switch. In its upper position, the frequency range is x10, in the lower it is ×1.) Use the high-pass table to select the right combination. See the appendix of this manual for keys to identifying the correct resistor network.

Inserting the resistor network—If there is a resistor network already installed in the socket, carefully pull it straight out. Insert the pins of the new resistor network into the socket holes and carefully press the network into the socket. Be careful to avoid bending the pins of the resistor network. Orientation of the resistor network is unimportant, as long as all 8 pins are well seated in the socket.

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