Proficient Audio Systems M40 User Manual page 19

The maximum number of speakers that can be connected to the M40 using impedance matching volume controls is four
pair. All four pair should be connected to the Speaker A Terminal as shown in Diagram 8.
Setting Impedance
1. The M40 is capable of handling a 4Ω load. For 4Ω amp configuration using Proficient VC60i Impedance Matching Volume Controls, use Chart 1.
If using another impedance matching device follow the manufacturer's instructions for that device.
2. Add up the number of 8Ω speakers that will be connected to one channel (left or right) of the amplifier or receiver. Find that number
under "Number of 8Ω Speakers" on Chart 1.
3.
Add up the number of 4Ω speakers that will be connected to one channel (left or right) of the amplifier or receiver. Find that number
under "Number of 4Ω Speakers" on Chart 1.
4. On the chart, follow the column under the "Number of 8Ω Speakers" and the row next to the "Number of 4Ω Speakers" until they intersect.
Set the slide switch to the letter in that box.
5.
The gray area indicates a setting that is slightly below the amplifier or receiver's minimum impedance, but will most likely work.
VC60i Example 1:
The Example System in Diagram 8 has four pair of Proficient C645 Ceiling Speakers connected to four Proficient VC60i Impedance Matching
Volume Controls. The C645 are all 8Ω speakers.
1.
To determine VC60i Slide Switch setting, use Chart 1.
2. There are four pair of 8Ω speakers. Find "4" under the
8Ω column on the chart.
3. There are no 4Ω speakers. Find "0" next to the 4Ω row
on the chart.
4.
The column and row intersect at "A".
5.
Set the Slide Switch to "A".
VC60i Example 2:
Example System 2 has one pair of 8Ω speakers and three
pair of 4Ω speakers.
1. To determine VC60i Slide Switch setting, use Chart 1.
2.
There is one 8Ω speaker. Find "1" under the 8Ω column
on the chart.
3.
There are three 4Ω speakers. Find "3" next to the 4Ω row
on the chart.
4.
The column and row intersect at "B".
5. Set the Slide Switch to "B".
Number of 8Ω Speakers
Chart 1 Proficient VC60i Slide Switch Settings
4Ω Amp Configuration
PROFICIENT
C645 CEILING
SPEAKERS
PROFICIENT
VC60i
IMPEDANCE MATCHING
VOLUME CONROLS
16AWG (min)
2-Conductor Stranded
Speaker Wire
1
SPEAKER IN
PASSIVE (NON-IMPEDANCE MATCHING)
1 IN, 4 OUT SPEAKER TERMINAL
Speaker A
Terminals
Diagram 8 Whole House Music Connections
19
CONNECTIONS
2 3 4
16AWG (min) 2-Conductor Stranded
Speaker Wire
M40 REAR PANEL