M&S Systems Car Amplifier User Manual

Introduction 

By matching the 

minimum output 

impedance of the 

receiver or amplifier 

and adjusting volume, 

M&S

™

   impedance-

matching volume 

controls eliminate the 

need for speaker selector 

boxes or other impedance 

matching equipment.

Determining the 

Jumper Setting for 

Impedance Matching 

To protect the amplifier 

from overload and 

damage, the jumper must 

be set in a position that 

correctly multiplies the 

impedance of the speaker 

system to a level that is 

equal to or greater than 

the impedance of the 

amplifier. For reference: 

All M&S

™

 Ceiling and 

In-Wall speakers are 8-

Ohm.

Step #1

Determine the amplifier’s 

minimum impedance. 

(The amp’s minimum 

impedance is usually 

found following Wattage 

and Frequency Response 

in the amplifier’s 

specification page of the 

manual. It may also be 

listed on the back panel 

of the amplifier near 

the speaker terminals). 

Impedance is measured 

in Ohms (8- and 4-ohm 

systems are common).

Step #2

Determine the total 

number of  speaker pairs. 

Step #3

Use the chart below to 

determine the correct 

jumper settings

.

Step #4

Set the jumpers.

Electrical Boxes and P-Rings

The mounting depth of the volume control is 2

7

/

8

" from 

the face plate to the back of the control. You must use an 

extended depth box to accommodate the volume control. 

A P-Ring can be used as an alternative if local building 

codes allow. 

Wiring Instructions

For best results, use M&S 16-gauge stranded MS16X5 

copper speaker wire. Never use solid-core, aluminum or 

"Romex" type wire with volume controls.

Step #1

Strip about 

1

/

4

" of the 

insulation off the ends of all 

wires. Twist the exposed ends 

to eliminate loose strands.

Step #2 

Connect the leads from the 

Receiver/Amplifier to the 

volume control connector 

labeled INPUT. Insert the 

LEFT L(+) and L(-) into 

the corresponding connector 

openings. Tighten the screws 

firmly, making sure that the 

exposed wire is engaged, not 

the insulation! 

Step #3

Repeat process while 

connecting R(+) and R(-) 

wires from the amplifier.

Step #4

Connect the speaker wires to the connector labeled 

OUTPUT. Observe channel and polarity output.

Step #5

Install the completed assembly into the junction box. 

Insert carefully to reduce strain on the connectors. If 

necessary, pre-dress the wires for easiest mounting.   

For Best Results and to Minimize Cross-Over Interference From Other Electronic Devices, 

Use The Following Guidelines When Planning Installation:

DON’T

 install in electrical boxes with 120V household wiring.

DON’T

 install near other wall controls, including light switches and dimmer switches.

DON’T

 install near a telephone or intercom master.

DON’T

 install in a bathroom or spa, or near a jacuzzi.

DO 

use only a power limited listed or recognized stereo amplifier to power this product 

(70 Volt Peak Maximum / 20Hz-20kHz).

Jumper Settings 

Cutaway

Note: 

Be sure every 

jumper setting 

is set the same 

throughout the 

system!

Impedance-Matching 

Volume Controls Only

NUMBER OF 

8-OHM PAIRS

1

2

2X

2X

4X

4X

8X

8X

8X

8X

3

4

5

6

7

8

JUMPER

SETTINGS

INSTRUCTIONS 

FOR 

IMPEDANCE-

MATCHING 

VOLUME 

CONTROLS

1. Make sure the amplifier 

  or receiver is OFF and 

  set the amp volume to 

 minimum.

2. Set the volume control 

  volume to maximum 

 (fully 

clockwise).

3. Turn on the amplifier or 

  receiver and select a 

  music source, such as 

 radio tuner or CD 

 player.

4. 

Slowly turn up the 

 amplifier or receiver 

  volume and set it to a 

 comfortable 

(not 

 maximum)  listening 

 level. BE CAREFUL 

  N O T  

T O  

  O V E R D R I V E  

 YOUR AMPLIFIER. 

  If the sound becomes 

 muddy or distorted, 

  you have reached the 

limit of your 

 amplifier’s volume 

 capacity and should 

 quickly 

reduce t h e  

volume to avoid 

 damaging 

your 

 speakers.

5. Use 

the 

M&S

™

 volume control to 

  adjust the volume of 

  the speakers to the 

  desired listening level 

  in each room.

6. Turn off the speakers in  

  a room by turning the  

  knob on the volume  

  control completely  

 counter-clockwise.

 VOLUME 

CONTROL

OPERATION

IMPEDANCE-MATCHING WIRING 

INSTRUCTIONS

Speaker Pair

Output

Input

Volume Control

Receive/Amplifier

PRINTER’S INSTRUCTIONS:

INSTR,INSTL,IM1 - LINEAR P/N: 115917-4 B - INK: BLACK, PMS 280 (BLUE) - MATERIAL: 80# STERLING GLOSS COVER OR EQUIVALENT - SIZE: 11.000” x 12.500” FINISH 5.500” x 6.250”- FOLDS: 1 VERTICAL, 1  HORIZONTAL- SCALE: 1-1 - SIDE 2 OF 2