ETS PMI-1 Instructions

PMI-1 Microphone Interface Instructions
The PMI-1 is a professional microphone DVR, IP camera or recorder, pre-amplifier and interface designed for use in
acoustically difficult and sound quality critical environments such as interrogation and court rooms. The PMI-1 is designed
to be used with balanced output, microphone level phantom powered or dynamic microphones.

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 15-25 feet but it is dependent on
the level of background noise in the area. Experimentation in the environment will determine what distances work best.

PMI-1 location and power

The PMI-1 interface box is designed to be placed near the DVR, I/P camera, PC or recorder. 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. The PMI-1 requires a 120VAC power source within 3 feet of its location. If this is not possible in your application,
you can splice in up to 100 feet of 18 awg, 2 conductor cable to extend the distance between the AC power source and
the PMI-1.

Microphone Cable Run

Run a professional grade microphone type cable (preferred) or a 22 gauge, stranded, two conductor shielded cable
between the PMI-1 module and the microphone. Keep the cable run distance at or under 500 feet and away from AC
power sources, light fixtures and electrical equipment.

Microphone input

Connect the microphone per the wiring diagram in figure 1.

Phantom power Switches

If you are using a phantom powered mic such as the ETS PCCM-1 or PM1 series microphones, turn the phantom power
switch on and select the appropriate phantom power switch Voltage (12v or 48v) with the other switch. If you are using a
dynamic microphone, turn the phantom power switch off.

Microphone preamp gain

If you are using a Phantom powered microphone, set this control typically at ¼ turn from full counter-clockwise. If you are
using a dynamic microphone, set this control to ¾ from full counter-clockwise.

Setting the PMI-1 Tone Controls (EQ)

Setting an equalizer for the desired overall sound is a subjective topic. We recommend using headphones to evaluate the
sound quality. Start with setting all controls to the mid-point (flat= no gain or cut). We suggest you do this when the
desired sound source is present (people taking, being interviewed, etc.) Adjust each control clockwise and counter
clockwise to get a feel for how each band affects the overall sound. Keep in mind that the human voice resides
predominately in the mid range. A typical setting for voice capture applications would be to place Bass in full counter-
clockwise, Middle at ¾ full clockwise and Treble at ½ clockwise.

Audio output

The PMI-1 features a "line level" audio output. It can be connected to any microphone or line level input of another device

Level output

Adjust this control for minimal distortion and sufficient amplitude on your end device. A good starting point is to set the
control half-way on. If you need to run the audio output into a microphone level input of another device, you should set this
control to 1/8 of a turn from full counter-clockwise and adjust the microphone gain control to bring the signal to a low
enough level to prevent distortion.