An audio mixer, also known as a mixing board or a soundboard, is used to control the levels of multiple inputs so that the sounds can be properly balanced. When recording music or performing live, mixing is essential to ensure that one instrument does not overpower the others. Using a mixer may appear intimidating at first, but it is not difficult once you understand what the knobs do. After you’ve connected your instruments or microphones, adjust the volume of each input until you’ve found the perfect mix!
Part 1 Connecting Your Equipment
1. Reduce the master volume and channel faders to zero. Locate the main volume control on the mixer’s bottom right side, which is usually labelled “Main Mix” or something similar. The faders are knobs or sliders that control the volume of individual inputs found along the bottom of the mixer. If the controls are knobs, turn them counterclockwise until they no longer move. If the controls are sliders, move them as far down as you can to reduce the volume.
If you turn on the mixer without first lowering the volume and faders, you risk creating loud feedback and/or damaging the mixer and/or speakers.
The main volume control and faders are usually a different colour than the other controls, making them easy to distinguish.
2. Using XLR cables, connect microphones to channels. XLR cables are used to connect microphones, and the ends have three pins enclosed in a metal cylinder. Your mixer will have XLR ports either along the top edge or on the back side. Connect the XLR cable to the microphone you’re using. Connect the other end of the XLR cable to one of the mixer’s ports marked with three small holes inside a circle. The number above the port indicates the input channel, which is a column of knobs on your mixer that controls that single input.
XLR cables can be purchased at a music store or online.
The number of inputs you can have on your mixer is determined by the number of channels it has. An 8-channel mixer can accept up to 8 different inputs, whereas a 32-channel mixer can accept up to 32 inputs.
3. Connect your instruments to your mixer’s line inputs. Line inputs on your mixer are located near the XLR ports for each channel and are compatible with 6.35 mm audio jacks. Connect the other end of your audio cable to the instrument you’re connecting. Then, on your mixer, select a channel that does not have another cable connected to it, and connect the other end of the audio cable to the line input. The number above the input indicates which channel controls the instrument’s audio.
An instrument cannot be plugged into a line input on a channel that already has an XLR cable plugged into it.
You can also purchase audio cables for instruments that use an XLR cable to connect to a mixer. For your audio, either will suffice.
4. To use monitors, connect the mixer output to an audio interface using TRS cables. TRS cables are a balanced audio source, which means they will produce less feedback and noise from your inputs, and they have 6.35 mm headphone jacks on the end. The master output ports should be near the top of the mixer or on the side near the other ports. Connect one of the cables to the port labelled “L,” and the other to the port labelled “R.” Connect the cables to your audio interface and plug them into the appropriate input ports on the interface’s back.
An audio interface and TRS cables can be purchased online or from a music store.
Audio from your mixer can be played back through speaker monitors or on a computer using interfaces.
5. Connect headphones to the mixer’s “Phones” port. Listening to your mixer through headphones allows you to clearly hear the levels so you can adjust them later. To connect your headphones to the mixer, use a 6.35 mm headphone jack. Check that the headphone cord is not tangled around any of the knobs.
You are not required to wear headphones if you do not wish to.
Tip: Most mixers do not have 3.5 mm ports for standard headphones. If your headphones do not fit in the mixer, you will need to purchase a 3.5 mm to 6.35 mm adaptor from a music supply store or online.
6. Use the power switch to turn on your mixer. The power switch is typically located on the back of the mixer or on the top right near the other knobs. Before flipping the switch to turn it on, make sure that all of the volume and fader controls are still turned down. As soon as the power is turned on, a light will illuminate.
Some mixers may have a “phantom” switch that supplies power to microphones that require it. Turn on the phantom power switch if you have a microphone that requires it.
Part 2 Adjusting the Sound Levels
1. Adjust the main volume to 0 dB. The main volume control will have numbers printed on the side so that you can see the output level easily. Push the slider or turn the knob until it reaches 0 dB, which is usually the highest setting. Any louder, and the sound will begin to distort.
Because the faders on each channel are still turned down, you won’t be able to hear anything through speakers or headphones.
2. Balance the channel faders so that you can clearly hear all of the inputs. Begin by moving the slider or turning the knob on one of the channels you’re using clockwise. Continue to turn up the faders for each channel with an input so you can hear it through your speakers or headphones. Check the inputs all at once to see if you can hear each microphone or instrument in the mix. Increase or decrease the fader levels until you can hear each audio source.
Turn the fader no more than 34 times to the maximum volume to avoid creating interference and muffled audio.
3. To change which frequencies come through, change the treble, mid, and bass settings. Each channel on your mixer has a column of knobs that control the channel’s treble, mid, and bass levels. The treble knob regulates the high frequencies, the bass knob regulates the low frequencies, and the mid knob regulates everything in between. As you adjust the knobs, listen to the audio input on the channel to see how the sound changes.
Lower the bass and increase the treble if the channel has a microphone attached to it to make it sound more prominent.
If the channel includes an instrument, experiment with each knob and playing the instrument to see how it affects the sound.
There are no perfect levels for your mix because they depend on the audio sources and the sound you want to achieve.
Tip: Some mixers have a “Lo Cut” button that eliminates all frequencies on a channel that are below a certain frequency level. To help cut unwanted low sounds, use the “Lo Cut” button on microphones and vocals.
4. To continue increasing the volume of specific channels, use the gain knobs. Gain knobs are typically found at the top of each channel and are labelled “Gain.” Slowly adjust the gain knob for the channel you want to boost the audio for and compare it to the other instruments to see if you can hear it clearly.
You don’t have to increase the gain for every input you use. All of the audio sources will sound muffled if you do this.
5. Adjust the pan knobs to direct the audio from the channel to the left or right speaker. The pan knobs, which are usually located directly above the channel faders, control the balance between the left and right speakers. When the knob is positioned in the centre, the audio is distributed equally between the left and right speakers. Turn the knob to the left if you want the audio to be more prominent from the left side, and to the right if you want it to be more prominent from the right side. Continue to fine-tune the pan for each channel.
If all of your audio sources are panned in the middle, the mix may sound flat.
If you want the input to come through both speakers but be more prominent in one of them, move the knob away from the centre.
Part 3 Isolating and Sending Channels
1. To turn off a channel’s audio, press the “Mute” button. Look for a small button labelled “Mute” near the channel fader. When you press the button, the audio from all the other channels continues to be routed through the mixer, while the selected channel becomes silent. When you want the audio to go through your mixer again, press the “Mute” button.
The original input source will not stop working if you press the audio button, but you will not be able to hear it through the mixer’s speakers or headphones.
If you want, you can mute multiple tracks at the same time.
2. To isolate a channel, click the “Solo” button. Look for a button labelled “Solo” next to the “Mute” button. When you press the solo button, all other channels are muted so that you can only hear the channel you chose. When you’re ready to begin the other inputs, press the “Solo” button again to turn it off.
When you solo a channel on a mixer, you can easily make changes to specific instruments or vocals without lowering the faders on the other channels.
You can solo multiple channels at once.
3. To “send” an audio signal to another source, use an auxiliary channel. Auxiliary channels are useful when you need to send audio copies to specific monitors or apply effects to them. To begin using the labelled auxiliary port, plug the monitor or effects rig into one of the ports on your mixer labelled “AUX.” To adjust the volume of the input, turn the knob labelled “AUX” on the channel you want to send.
Make sure you’re using the auxiliary knob that corresponds to the auxiliary channel you’re connected to.
Multiple channels can be routed to an auxiliary channel.
For example, if you’re a singer and want to hear the drums and guitars in a monitor to stay on beat, you can use an auxiliary channel.
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