3
Speakers & Volume Controls
VCIR-CFL
WHEN USING 8 OHM SPEAKERS
WHEN USING 4 OHM SPEAKERS
Number of Speaker Pairs Used
Min. Amp.
Impedance
S1
S4
1 2 3 4 5 6 7 8
S4
S4
S8
S8
S8
S8
S4
S4
S8
S8
4 Ohms
8 Ohms
Number of Speaker Pairs Used
S1
S1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
S4
S4
S4
S4
S4
S4
S8
S8
S8
S8
S8
S8
S8
S8
S1
S4
S4
S4
S8
S8
S8
S8
Min. Amp.
Impedance
4 Ohms
8 Ohms
1. Determine the rated speaker impedance (refer to the manufacturer's specifications - it must be the
same for all speakers used in the system).
2. Determine the total number of stereo speaker pairs used in the installation.
3. Determine the minimum safe operating load impedance for the amplifier (refer to the manufacturer's
specifications).
4. Find the correct jumper position from the above charts.
5. Place the jumpers in the same position on each VCIR-CFL used in the system.
Example 1:
Three pairs of 4 Ohm wall speakers are to be used with three VCIR's in a 3-room system, all driven by one
amplifier rated for 8 Ohms minimum safe operating load impedance.
1. Refer to the chart "WHEN USING 4 OHM SPEAKERS".
2. Locate the number 3 in the top row.
3. On the 3rd row, opposite "8 Ohms" and below "3", note the letters "S8". These signify the required
impedance multiplier.
4. The two jumpers therefore, one for each channel, need to be plugged onto the S8 pins on each VCIR-
CFL in each room.
Example 2:
Seven pairs of 8 Ohm wall speakers are to be used with seven VCIR's in a 7-room system, all driven by one
amplifier rated for 4 Ohms minimum safe operating load impedance.
1. Refer to the chart "WHEN USING 8 OHM SPEAKERS".
2. Locate the number 7 in the top row.
3. On the next row, opposite "4 Ohms" and just below "7", note the letters "S4". These signify the required
impedance multiplier.
4. The two jumpers therefore, one for each channel, need to be plugged onto the S4 pins on each VCIR-
CFL that feeds each room.
If using speakers of differing impedance, refer to:
Procedure for Speakers Other Than 4 or 8 Ohms" and "Procedure for Speakers of Different
Impedance Used in the Same System"
under Model 760-00 in the Xantech Applications Manual.
