SM5-EA Microphone Kit Instructions
The SM5-EA is a single channel, one way pre-amplified microphone “listen in” surveillance kit designed to be used with
Power Over Ethernet IP cameras. It provides a convenient way of supplying power to the SM1 by tapping power off the
camera’s Ethernet connection. The SMEA-1 interface features installer friendly termination of the cable runs and a
standard RCA or 3.5mm audio output connector. The output of the SMEA-1 can be used on microphone or line level
inputs of PoE IP camera. The SMEA-1 can be connected to a “microphone” or “line” level input of a PoE IP camera.
SM1 Microphone Placement
Locate the SM1 microphone as close as possible to the area of interest in the space to be monitored. If a large area is to
be monitored, locate the SM1 in the middle of the room. Do not mount the microphone near air conditioning vents, light
fixtures or electrical equipment. The SM1 should be placed as close as possible to the subject(s) to be monitored. The
SM1 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.
SMEA-1 location and power
The SMEA-1 interface box is designed to be located any place along the IP camera CAT5 cable run. It must be located in
between the IP camera and the router or switcher as shown in figure 1.
NOTES-
1. The IP camera MUST be connected or the SMEA-1 will not power up.
2. The SMEA-1 will not work with non-PoE IP cameras.
Cable Run
Run a 22 gauge, stranded, two conductor shielded cable between the SMEA-1 interface and the SM1 microphone. Keep
the cable run distance under 1,000 feet and away from AC power sources, light fixtures and electrical equipment.
See
Figure 1 for connection diagram.
Mounting
The SM1 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 SM1 to the surface with screws.
Adjusting the SM1 “gain” and SMEA-1 “level” controls
If the SM5-EA will be plugged into a “microphone level” input of an IP camera, set the SM1 gain slightly clockwise (or 1/8
of a full turn) from full counter-clockwise. Then use the “level control” on the SMEA-1 to set a volume that produces an
acceptable audio level at the head end.
If the SM5-EA will be used with a “line level” input, turn the gain control of the SM1 to 3/4 full clockwise and adjust the
level control on the SMEA-1 to produce the clearest audio level at the head end.
Setting the SM1 Jumpers
The “Volume Range” jumper should be set to the “LO” position when using the SM1 with IP cameras that utilize
“microphone inputs” also known as “Mic. Level” inputs. This sets the maximum gain of the SM1’s pre-amp to x11. The
jumper 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’s pre-amp to x121.
The normal frequency response of the SM1 microphone is 500-13Khz. When both jumpered “in”, The “HI Cut” and “Lo
Cut” filters set the SM1’s frequency response to 900-3.9Khz . Enabling one or both of the filters is useful when
background noise needs to be reduced and intelligibility of speech emphasized. We recommend experimenting with the
jumper settings to achieve the best acoustic result for your application (s).
SMEA-1 Mode switch:
The SMEA-1 supports Both Modes A and B of IEEE802.3af POE. The SMEA-1 is
pre-configured for the most common use of the “end point” POE IEEE802.3af standard (mode A). If the power LED does
not illuminate in this position, try the mode B position (mid span).
