ETS SMI-1U Instructions

SMI-1U Microphone Interface Instructions
The SMI-1U Microphone PC interface is for use with ETS SM1 series microphones or similar. Features include adjustable
gain adjustable low cut filter in two ranges and Mute switch with indicator.
Microphone Placement
Locate the microphone as close as possible to the area of interest in the space to be monitored. Do not mount the
microphone near air conditioning vents, light fixtures or electrical equipment. Most microphones operate optimally 3-5 feet
away from the subject(s) to be monitored. Microphones are still useable in the range of 5-25 feet but it is dependent on
the level of background noise in the area. Experimentation in the environment will determine what distances work best.
SMI-1U location and power
The SMI-1U interface box is designed to be placed near the PC or other USB compatible device. Once all settings are
made, the interface can be located out of view. All controls are recessed to reduce the possibility of accidental "bumping"
of settings.
Microphone Cable Run
Run a professional grade microphone type cable (preferred) or a 22 gauge, stranded, two conductor shielded cable
between the PMI-1U module and the microphone. Keep the cable run distance at or under 1000 feet and away from AC
power sources, light fixtures and electrical equipment.
Microphone Volume
Set this control for the best undistorted sound. Mid range for near field audio pickup and full Clockwise for far field pickup.
Experiment with the settings for the best result.
Low Cut control
The SMI-1U includes a low cut control in two ranges for applications where pickup of low frequencies are less desirable.
When turned to the fully clockwise or 150hz or 1500hz position, ambient background noise will be significantly reduced.
When fully counterclockwise the frequency is limited to 20 or 200hz
Connecting to PC
In sound settings of windows, select PnP Audio device for microphone input. We suggest setting the mic volume to
midrange for near field applications and full volume for far field applications. Experiment with the settings for the best
result.
Figure 1