Sound Board Configuration

Description of the typical sound board connections and operation for normal worship services.

The audio mixer is a Mackie SR24-4 24 channel audio board. It is setup in a mono configuration with the left and right speakers getting the same audio signal from the amplifier. Channels 1-20 are independent channels, meaning they each have their own settings and connections. Channels 21/22 and 23/24 are stereo inputs.

Channels 1-20 Description

These channels each have 3 inputs: XLR mic, 1/4″ TRS (tip-ring-sleeve) phone jack line in, and 1/4″ TRS phone jack insert. The mic inputs can accept balanced inputs from almost any type of source with -60dBu to +14dBu levels. They are capable of providing 48V phantom power if necessary. The “Phantom” switch near the power cord connector must be turned on to provide phantom power to all 20 mic inputs. See figure A below for proper mic connections. The line in inputs can accept balanced or unbalanced inputs when wired as follows:

Balanced: Tip = Positive (+ or hot), Ring = Negative (- or cold), Sleeve = Shield or ground

Unbalanced: Tip = Positive (+ or hot), Sleeve = Shield or ground

The insert inputs are for connecting aux subs or other equipment (special effects, equalizers, etc) into a specific channel. For the most part these are not used at Calvary. Any use of these will be explained later.

Channel Control Description

Starting at the top of the board and working down toward the sliders are the following controls (See figure at right):

Trim: This is a coarse input sensitivity. These knobs should be adjusted very little as they have a 60 dB adjustment from fully CCW to fully CW. This would be used to set the volume of a channel to a desired level that results in the slider (fader) being close to the “U” or unity position.

Aux Sends 1-6: These knobs set the level for the 6 auxiliary send connections. These tap off the channel signal to route to one or more aux devices. 1-2 are pre-fader meaning the fader level and equalizer do not affect their level. 3-4 can either be pre or post fader depending on the position of the “PRE” switch. If it is pressed down then it will be pre-fader other wise it is post fader, or the fader level will affect the level of the aux send. 5-6 are post-fader.

Equalizer Control: The board has a 3 band equalizer (High, Mid, & Low frequency) plus a switchable low cut filter. These knobs can be used to enhance or reduce tracks, voices, etc for those 3 basic bands. The center position of the knob is unity, or no affect on the signal. The low cut filter is handy to get rid of room rumble, or reduce noise from mic handling or breath noise.

Pan: This knob is left at the middle position since we run a mono configuration. If it is turned then just make one speaker softer/louder than the other.

Mute: This button mutes the specific channel. The input will still drive the -20 or OL LED beside the Pan knob. These lights are useful for determining if you have input on the channel when the channel is muted.

Fader: This adjusts the level of the channel sent to the amplifier. Generally this should be set at “U” or within +/- 5 dB of “U” (the white shaded band).

Solo: Pressing this button will send the specific channel to the level meter. This can be used to set the level for that channel. We try to set this so the max level is between -4 to 0 dB.

1-2, 3-4, & L/R: These set which outputs the channel will be sent to. 1-2 are the hard of hearing receivers and foyer speakers. 3-4 not used, and L/R is the main mix. All channels have the 1-2 pressed with the exception of the drums (Channel 9) as they will make the foyer speakers pop with the bass drum.

Aux Sends

The following list is the standard configuration for the aux sends used on a typical day.

Aux Send Definition (Std. Configuration)

Aux 1:  Main floor monitors
Aux 2:  Drum monitor 
Aux 3:  Not Used
Aux 4:   Sub Woofer Feed
Aux 5:  Recording Feed (Also Live Stream Feed)
Aux 6:  Family Life Center (Gymnasium Feed

Each one of the aux sends has a master level control knob [13] as well as a solo button [14] to send the level(s) to the “Main Mix” level meter.

Channel Definition (Std. Configuration)

The following list is the standard configuration of the channels used on a typical day.

Ch 1:  Pulpit Mic
Ch 2:  Supper Table Mic (Shure SM58) 
Ch 3:  Piano Mic 
Ch 4:  Green Mic (Shure SM58)
Ch 5:  Keyboard
Ch 6:  Yellow Mic (Shure SM58)
Ch 7:  Blue Mic (Shure SM58)
Ch 8:  Red Mic (Shure SM58)
Ch 9:  Drums
Ch 10: Video (computer audio)
Ch 11: Pastor (Shure Wireless Mic)
Ch 12: Music Minister (Shure Wireless Mic)
Ch 13: Gray (Telex Wireless Mic)
Ch 14: Blue (Telex Wireless Mic)
Ch 15: Green (Telex Wireless Mic)
Ch 16: Red (Telex Wireless Mic)
Ch 17: Guitar
Ch 18: Bass Guitar
Ch 19: CD Vocals
Ch 20  CD Track
Ch 21/22: Mobile Phone Audio (1/8" input)
Ch 23/24: Cassette Tape

Right Side of Mixer

The following describes the upper right corner of the mixer. Starting at the top and work down

The left side has the Aux Send Masters [13]. These knobs set the overall level for each of the 6 aux sends. They each have a corresponding Solo button to send the level to the level meter to help in setting the overall level for that aux send.

Beside the Aux Send Masters are the Stereo Aux Returns [16 & 17]. These are normally not used at Calvary. They can be used to get returns from an effect processor or other line-level signal sources.

Beside those are the “To Aux Send 1-2 (EFX to Monitor)” [18 & 19] controls. These work independently of the aux returns own level control. They allow you to send return signals (such as delay and reverb) to the stage monitors.

The rest of these controls are too deep into the weeds for this document. The only knobs normally used at Calvary are the Aux Send Masters 1-6.

Talkback: This allows the sound operator to communicate from the board using a microphone plugged into the Talkback input. As you would expect the knob controls the level. The Main Mix and Aux 1-2 buttons control which outputs receive the talkback signal. Main mix would send it to the main speakers and Aux 1-2 would send it to the floor monitors and drum monitor.

Main Fader Controls

The following describes the operation of the main fader controls in the lower right corner of the mixer.

Sub 1:  Foyer speaker and hard of hearing system level.  Typically set at -5dB.

Sub 2:  Not Used

Sub 3:  Not Used

Sub 4:  Not Used

Main Mix:  Sets the level of the main speakers.  This is typically set at -5dB.

Stage Connections (Std Configuration)

The sound system is designed to be easily configurable for special events and programs. There are 5 connection panels on the stage and 3 connection panels under the front pew. Each one of these panels have different connections to allow microphones, and speakers to be connected into them and therefore connected to the sound board in the booth at the back of the sanctuary. Configuration can be changed rather quickly simply by connecting a different connection panel input to a different channel on the sound board.

The figure below details the locations of each of the connection panels mounted in the stage.

Need to add pictures of stage panels.

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