Using an Audio Mixer

>Meetinghouse Technology > Audio Video Distribution

Note: These instructions assume that the user has a Mackie 402VLZ4 or similar mixer and an LDS/MECP wiring kit, both of which are available through Poll Sound. The total cost of these two items is typically just under $200 USD. Poll Sound serves the United States and Canada. It is located at 4026 South Main, Salt Lake City, UT 84107. The phone number is 1-801-261-2500. Outside of the United States and Canada, contact the area office for assistance in ordering similar meetinghouse webcast products and components.

A stake center satellite system usually includes equipment to create a TV feed from the chapel and send it to TV sets in other rooms, such as the Primary and Relief Society meeting rooms. These rooms can then be used for overflow seating, by parents with young children, or for the broadcasting of additional languages.

The following setup feeds the sound from the chapel sound system into a mixer. This enables the technology specialist to better control the audio levels input into the webcast encoding device.

1. In the satellite TV equipment rack, locate the chapel or camera modulator (Note: This is the equipment that creates the TV channel).

• Find the audio input on the modulator (usually on the back). Unplug the audio cable that feeds the camera modulator (input). Plug the male end of the Y cable into the modulator. (The Y cable and all other cables used in this setup are included in the LDS/MECP wiring kit.)
• Plug the cable you just unplugged from the modulator into one leg of the Y cable.
• Find the cable in the kit that has an RCA connector on one end and a ¼-inch headphone connector on the other end. Plug the RCA end of the cable into the empty leg on the Y cable. Plug the ¼-inch headphone connector into the “audio input 1” on the mixer.

Note: With these connections made, the gain or volume on the mixer can be set up.

1. Have someone talking at the pulpit in their normal voice. On the mixer, find the knob labeled “Gain” by the input connector. This knob adjusts the first stage gain trim. Locate the channel volume knob at the bottom of the mixer. Just above and to the right of this knob is a little red LED light. Adjust the gain trim knob until the light turns on when the person at the pulpit speaks, then turn the knob clockwise until the light never comes on while the person is speaking.

Note: Whenever this light is on, the sound is distorted. Generally, once the gain trim knob has been adjusted, it will never need to be adjusted again. However, if someone speaks with an exceptionally loud voice, the light may turn on. If this happens, turn the trim knob down a bit until the light goes off. After that individual has finished speaking, return the trim knob to its original setting.

1. On the mixer, just above the input control knob is a push button. This button either separates or combines the input signals. For a meeting such as a stake conference, the input signals should be combined. You can test if the signals are combined by having someone speak at the pulpit while you turn the volume control (bottom knob) up. If both VU meters respond, the button is in the combined position. If only the left VU meter lights up, the signals are separated. Push the button to combine the channels. Both VU meters should now respond and have the same readings.

Connections to the Webcast Encoding Device

The items from the cable kit that have not been used yet include:

• A cable with a 1/4-inch male connector on one end and an XLR male (three-pin mic plug) connector on the other end.
• A cable with an XLR female connector on one end and a 1/8-inch stereo earphone male connector on the other end.
• A 30 dB pad.
• A cable with a 1/4-inch male connector on each end.
• An Emtec EJ-R and a coiled phone handset cord.

Final steps

Using the stake conference setup as an example, let’s assume that the left output from the mixer feeds into the webcast encoding device and the right output feeds into the telephone backup device. See more on Audio Backup

1. Locate the 1/4-inch male to XLR male cable and plug the 1/4-inch end into the left output on the mixer.
2. Locate the 30 dB pad and plug it into the XLR male connector end of the cable.
3. Locate the XLR female to 1/8-inch stereo cable and plug the XLR end into the 30 dB pad.
4. Plug the 1/8-inch stereo end of the cable into the 3.5 mm audio input on the webcast encoding device.

Note: The audio from the sound system is now connected to the webcast encoding device. The mixer is also connected so that the user can see the volume of the sound being transmitted and adjust it as needed.

For normal operations, adjust the volume knob for channel 1 on the mixer so that the LEDs on the VU meter come up to, but not above, zero. If they are above zero, the audio will be distorted at the receiving sites.

Note: Normal operations for an event require that the input knob be adjusted each time a new person starts speaking or when music is being presented. The input knob can rarely be left in the same position for an entire meeting.

For additional support, contact the Global Service Center.