ETS DM1-SS Instruction Manual

DM1-SS Microphone Instructions
The DM-1-SS is a flush mount omni-direction microphone with an integrated DSP (Digital Signal Processor)
based background noise eliminator unit. It is designed to Digitally screen out all repetitive back ground sounds
and passes through / enhances the human voice. The DM-1-SS is ideally suited for high noise environments.
Note- the audio output of the DM1-SS is "line level" (0db).

SM1 Microphone Placement

Locate the DM1-SS Microphone near the area of interest in the room to be monitored. If the entire room is to be
monitored, locate the DM1-SS in the middle of the room. Do not mount the microphone near air conditioning vents, light
fixtures or electrical equipment. The DM1-SS should be placed as close as possible to the subject(s) to be monitored. The
DM1-SS is still useable at distances of up to 25 feet but is dependent on the level of background noise in the area.
Experimentation in the environment will determine what distances work best.

Cable Run

Run a 22 gauge, stranded, two conductor shielded cable between the DM1-SS microphone and the monitoring device.
Keep the cable run distance under 1,000 feet and away from AC power sources, light fixtures and electrical equipment. If
you are connecting the DM1-SS to an ETS product, connect power to right-most power terminal of the DM1-SS and
ground to the ground terminal. The Ground of the power and audio signal must share a common ground for proper
operation. See Figure 1 for connection diagram.

External Power Source

The DM1-SS can be independently powered from any voltage source in the ranges of: 12Vdc – 24Vdc. See Figure 2 for
connection diagram.

Mounting

The DM1-SS can be surface or flush mounted on ceilings or walls. For flush mounting, cut a 2 ¼" by 2 ¾ " hole in the wall
or ceiling tile to allow room for the circuit board and mount the DM1-SS to the surface with screws. A single gang electrical
box can be used for surface mounting or consider using an DM1-SS in place of the DM1-SS.

Adjusting the Automatic Gain Control (COMPP)

The DM1-SS features automatic control of gain. This is useful for environments where it is anticipated that sound levels
will range from quiet to loud. This prevents the end user from having to constantly readjust the volume of the base station
to the audio environment and to reduce the possibility of pre-amplifier clipping (distortion). The best way to set this control
is to adjust it to a comfortable volume level (on an ETS base station or PC monitor speakers) when the loudest sounds
are present and constant. Turning the control CW will increase the amount of gain reduction during loud sound intervals. If
the sound is reduced too much during loud sounds, turn the control CCW a small amount and experiment until a
comfortable medium is found. We recommend a setting of 1/16 CW from full CCW for most applications.

Adjusting the DM1-SS Volume

Start with the Volume set at midrange. If the sound at the "head end" is distorted, rotate the control towards the – mark
(counter-clockwise CCW). If the volume at the "head end" is too low, rotate the control towards the + mark (clockwise
CW). Note- the DM1-SS output signal can be used to drive a microphone level input (-60db) of a DVR or I/P camera by
turning the volume all the way down (full CCW) and then CW a small amount.