ETS SM1-U-PM Instruction Manual

The SM1-U-PM is a high quality, 12V-24VDC powered, pre-amplified, moisture resistant, Uni-
directional microphone designed to connect to DRVs, IP cameras, etc. Note- the audio output of
the SM1-U-PM is switch selectable "line level" (0db) or "microphone level" (-30db).

Microphone

Plug the ML1-U-PM microphone into the "mic in" jack of the SM1-PA pre-amplifier. Do not mount
the ML1-U-PM microphone near air conditioning vents, light fixtures or electrical equipment.
The ML1-U-PM microphone should be placed as close as possible to the subject of interest. The
ML1-U-PM microphone is useable in the range of 3-25 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 SM1-U-PM pre-amplifier
and the monitoring device. Keep the cable run distance under 1,000 feet and away from AC
power sources, light fixtures and electrical equipment. Connect power to the + terminal, the audio
signal to the "audio" terminal and ground to the – terminal. The Ground of the power and audio
signal must share a common ground for proper operation. See Figure 1 for connection diagram.

Mounting

The SM1-U-PM Is designed to be panel mounted in panels up to .110 thick.

Adjusting the SM1-U-PM Gain

The SM1-U-PM output level is set by selecting the desired volume range and adjusting the gain
control.
The "Volume Range" switch should be set to the "LO" position when using the SM1-U-PM with I/P
cameras that utilize "microphone inputs" also known as "Mic. Level" inputs. This sets the
maximum gain of the SM1-U-PM's pre-amp to x14. The switch should be placed in the "HI"
position when using I/P cameras with "Line level" inputs of DVRs and I/P cameras. This sets the
maximum gain of the SM1-U-PM's pre-amp to x196.
The SM1-U-PM is shipped with the gain set at midrange. If the sound at the "head end" is
distorted, rotate the control towards the – mark (counter-clockwise). If the volume at the "head
end" is too low, rotate the control towards the + mark (clockwise).

Setting the SM1-U-PM Hi-Cut/Lo-Cut Switches

The normal frequency response of the SM1-U-PM microphone is 500-13Khz. When both
switched "On", The "HI Cut" and "Lo Cut" filters set the SM1-U-PM's frequency response to 900-
6Khz . Enabling one or both of the filters is useful when background noise needs to be further
reduced and intelligibility of speech emphasized. We recommend experimenting with the jumper
settings to achieve the best acoustic result for your application.
SM1-U-PM Microphone and
Pre-Amplifier Instructions