
SM1-ULE2 Microphone Instructions
The SM1-ULE2 is a high quality, 12-24VDC powered, unidirectional, surface mount, pre-amplified
microphone for use with DRVs, IP cameras, etc. Note- the audio output of the SM1-ULE2 is
switch selectable “line level” (0db) or “microphone level” (-30db).
SM-ULE Microphone Placement.
Locate the SM1-ULE2 Microphone near the area of interest in the room to be monitored. If the
entire room is to be monitored, locate the SM1-ULE2 in the middle of the room. Do not mount the
microphone near air conditioning vents, light fixtures or electrical equipment. The SM1-ULE2
should be placed as close as possible to the subject(s) to be monitored. The SM1-ULE2 is usable
at 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 SM1-ULE2 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. 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-ULE2 is designed to be mounted on any flat surface. The cable can be routed into the
SM1-ULE2 from the side or from the rear of the enclosure.
Adjusting the SM1-ULE2 Gain
The SM1-ULE2 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-ULE2 with IP
cameras that utilize “microphone inputs” also know as “Mic. Level” inputs. This sets the
maximum gain of the SM1-ULE2’s pre-amp to x14. The switch should be placed in the “HI”
position when using IP cameras with “Line level” inputs of DVRs and IP cameras. This sets the
maximum gain of the SM1-ULE2’s pre-amp to x196.
The SM1-ULE2 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-ULE2 Hi-Cut/Lo-Cut Switches (open the enclosure to adjust)
The normal frequency response of the SM1-U microphone is 500-16Khz. When both switched
“in”, The “HI Cut” and “Lo Cut” filters set the SM1-ULE2’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 switch settings to
achieve the best acoustic result for your application.