Public Talkback - Overhead Speaker

Required Parts And Tools

• Output Speaker (may be overhead or in wall mounted)
• Shure MX393 Boundary Mic
• RDL STM-1 Preamp
• XLR Tail
• RDL ST-VOX1
• Speaker Amplifier (Fosi or comparable)
• Ceiling Speaker (6 1/2")
• Drill
• Drywall Saw
• 22/2 audio cable
• B-connectors
• Crimper
• Fish Tape or Glow Rods
• Electrical Tape
• Wire Stripper
• Pencil

Installation Instructions

Mounting the Speaker

1. Determine the best placement for the speaker in the room.
2. Carefully remove the ceiling tile
3. Using a pencil, trace the speaker template centered in the ceiling tile.
4. Carefully cut the tile with a drywall saw
5. Remove the speaker grill to be able to fasten the speaker in place. Using a drill, tighten the speaker in place. Be sure not to overtighten in order to avoid damage to the tile.
6. Replace the grill and place the tile in the ceiling.

Mounting the Audio

1. Decide where the STM-1 will be located, knowing the MX393 mic will need to reach it.
2. Using a stud finder, determine the best location to route the 22/2 cable
3. Cut a hole into the drywall, large enough to fit a mud ring into it securely.

   

4. Using glow rods or fish tape, pass the 22/2 behind the wall routing to the STM-1
5. Secure a pass through plate to the mud ring mounted for the XLR just ran
6. Place the MX393. Splice the XLR tail to 22/2 using B connectors. This mic line will connect the mic line to the STM-1

   Note: The wires of the XLR will wire to the +, -, and ground Input on the STM-1.

7. Mount the STM-1 above the ceiling
8. Wire the red to the + and black to the ground power terminals on the STM-1.
9. Cut a length of 22/2 from the STM-1 to the camera. Strip the jacket on both ends. Cut away the bare wire and plastic surround the cable inside. Strip away a small piece of the red and black jackets revealing the bare copper wire.
10. A short piece of 22/2 cable will also be needed (approx. 1 inch).
11. Strip the jacket from the cable and remove all contents keeping only the red cable.
12. On both ends of the red cable, strip off a piece of the jacket. Connect one end of the 1 inch audio cable to the +PWR terminal and connect the other end into the +PHNTM terminal.
13. Run another length of 22/2 cable from the STM-1 to the a ST-VOX1

Wiring the ST-VOX1

1. Connect a line from the High Z of the STM-1 to the ST-VOX1 to the center port of the input on the device labeled as a line diagram (see wiring diagram)
2. From the Camera, run three lines of 22/2. One will be connected to the input and two will be connected to the output.
3. Connect the 22/2 connected to the camera input to the first port on the line diagram input. Connect one of the 22/2 connected to the camera output to the input port labeled Line.
4. The third 22/2 will connect to the speaker amp. Connect the speaker to the amp

   Note: All lines connected to the ST-VOX1 utilize shared ground