How to Set Up an Audio Mixer for Good Sound

Setting up an audio mixer can look complicated if you're faced with a panel full of knobs, switches and inputs for the first time. For a straightforward PA system, however, the basic process is relatively simple. Connect your audio sources, establish sensible input gain, balance the individual channels and then set the overall level of the system.

The most important thing is to work through those stages in the right order. Randomly adjusting controls until the PA sounds loud enough can produce distortion, excessive background noise or microphone feedback. A methodical setup gives you a much better starting point and makes problems easier to identify if something doesn't sound right.

Connect the Mixer Before Turning Everything Up

Start with the system levels turned down. Connect microphones and other audio sources to the appropriate mixer inputs, then connect the mixer's main outputs to the PA system.

With the powered speakers commonly used for portable PA systems, the mixer output connects directly to the speakers because amplification is built into each speaker enclosure. A system using passive speakers requires a separate power amplifier between the mixer and speakers.

For a typical Audio Hire system using professional powered Electro-Voice speakers, the basic signal path is straightforward: your microphones and music sources connect to the mixer, and the mixer sends the combined audio signal to the powered speakers.

If you're using wireless microphones, the wireless receiver connects to the mixer rather than the microphone itself. The microphone sends its signal to the receiver by radio, and the receiver provides the audio output that feeds the mixer.

Start With the Mixer Controls in Sensible Positions

Before setting levels, check the mixer rather than assuming its controls are where you need them. If somebody previously used the mixer, the gain or EQ controls may have been left in settings that are completely inappropriate for your system.

As a starting point, keep EQ controls in their neutral positions rather than immediately boosting bass or treble. Turn down channels you're not using and make sure any unnecessary effects or processing are disabled. The objective at this stage is to establish a clean, predictable starting point.

On mixers with channel faders, the normal or unity position is usually clearly marked. Compact mixers may use rotary level controls instead. The exact controls vary between models, but the principle remains the same: establish a sensible channel and master level, then set the input gain around the actual signal being received.

Set the Gain Properly

Gain is one of the most important controls on a mixer and one of the easiest to misunderstand. It determines how strongly the incoming microphone or other audio signal enters the mixer's signal path. It is not simply another volume control.

For a microphone, have the person speak into it at approximately the level they will actually use during the function. If you're setting up for a presenter, don't ask them to whisper during soundcheck and then set the gain around that. If you're setting up a vocalist, they need to sing at something reasonably close to performance level.

Increase the input gain until the mixer is receiving a healthy signal without clipping or overloading. Many mixers provide a peak or clip indicator that helps with this. Occasional activity close to the upper end of the meter can be normal, but persistent clipping means the input gain is too high.

The goal is a strong, clean signal with adequate headroom for louder moments.

Set Each Source Individually

If your mixer has several microphones or other sources connected, work through them individually. Set one microphone, then the next, followed by music sources or other equipment.

This is particularly important when several people are speaking. Different voices can produce very different levels through otherwise identical microphones, so copying the same gain setting across every channel doesn't guarantee a balanced result.

With a multi-presenter wireless system, for example, one person may have a strong projected voice while another speaks quietly. Independent mixer channels allow those differences to be accommodated without changing the overall PA level.

Once the individual inputs have been set correctly, use their channel level controls or faders to create the balance you want in the final mix.

Use EQ Carefully

It can be tempting to start adjusting EQ as soon as you see bass, mid and treble controls, but good sound doesn't come from using every knob on the mixer.

Start with the EQ neutral and listen. If a microphone already sounds clear and natural, there may be little reason to make substantial changes. If something sounds boomy, harsh or difficult to understand, modest EQ adjustments may help.

For speech, clarity is generally more important than producing a large, bass-heavy voice. Excessive low-frequency energy can make speech sound muddy and can amplify handling noise, bumps and other unwanted sounds. Some mixers provide a high-pass filter specifically to reduce unnecessary low frequencies on microphone channels.

EQ can help refine a sound, but it cannot compensate for poor microphone technique, badly positioned speakers or an inappropriate PA system.

Set the Main PA Level

Once the individual mixer channels are behaving correctly, bring the overall system to the required listening level. This involves the mixer's main output and the level controls on the powered speakers or amplifier.

You want useful level without forcing one stage of the signal chain excessively hard while another is barely being used. This idea is known as gain structure. Each part of the system should operate within a sensible range so that the audio remains clean and there is enough headroom for peaks.

There isn't one universal knob position that is correct for every mixer and speaker combination. Different equipment has different input sensitivities, output levels and recommended operating ranges. If you're using hired equipment, following the supplied setup instructions is preferable to relying on a generic rule such as “always put the speaker at maximum.”

Position Microphones and Speakers Before Chasing More Volume

If a microphone begins to ring or squeal as you increase the PA level, the problem may not be the mixer setting. Microphone and speaker positioning have a major influence on how much usable level you can achieve.

Feedback occurs when sound from the PA is picked up by a microphone, amplified and sent through the system again. If that loop becomes strong enough, it produces the familiar howl or squeal.

Keep microphones behind the main PA speakers rather than directly in front of them wherever the setup allows. The person using the microphone should also keep it appropriately close to their mouth. A microphone held too far away usually requires more gain, which increases the amount of surrounding sound it captures and can reduce the system's resistance to feedback.

Our guide to How to Stop Microphone Feedback covers this in more detail.

Set Music and Microphones at Different Levels

A system used for both speech and music normally needs some active level management. Background music that sounds appropriate before a presentation may be far too loud underneath someone speaking, while a microphone set for a quiet presenter may seem unexpectedly loud when somebody with a stronger voice takes over.

Use the mixer rather than continually changing the speaker levels. That's one of the reasons the mixer exists: individual sources can be adjusted while the overall PA system remains at an appropriate operating level.

For a presentation, you might reduce or mute the music channel when somebody begins speaking and bring it back afterwards. For more complex functions, a sound technician can manage those changes throughout the program.

Do a Proper Soundcheck

A soundcheck is the point where you test the complete system under conditions reasonably close to those in which it will actually operate. Check every microphone, every music source and every speaker rather than assuming that because one part works, everything works.

Walk through the audience area while listening if possible. A system that sounds loud beside the mixer may be completely different at the rear of the room. Listen for clear speech, appropriate music level and reasonably even coverage across the area where people will actually be.

If several wireless microphones are being used, test them all. If a laptop or phone is supplying music, play audio from the actual device. If a presenter will move around the room, test the microphone while moving through the areas they intend to use.

A few minutes spent doing this before guests arrive can prevent a great deal of troubleshooting later.

Don't Keep Turning Up the Mixer to Solve Every Problem

When something is difficult to hear, the instinctive response is often to turn it up. Sometimes that's appropriate, but not always.

If speech isn't clear, the problem might be microphone position rather than volume. If people at the rear of a long room cannot hear properly, the issue may be speaker coverage. If music lacks the low-frequency impact required for a dance floor, adding more level to the main speakers is not necessarily a substitute for an appropriately configured system with subwoofers.

Good PA setup is about getting the whole system working properly rather than finding the control that makes the largest number on the meter.

What Is the Basic Mixer Setup Order?

For a straightforward PA system, a useful sequence is:

Connect the sources and PA → establish neutral starting settings → set input gain → balance individual channels → make necessary EQ adjustments → establish the overall PA level → check for feedback → soundcheck the complete system.

Working in this order separates the different jobs performed by the mixer. If you later need to change the volume of one presenter, you can adjust that channel rather than disturbing the entire system.

Once you understand this sequence, even a mixer with many more channels becomes easier to interpret. The controls are repeated because the same basic process is being applied to multiple audio sources.

Mixer and PA Hire in Adelaide

Audio Hire supplies mixers with PA systems where the application requires control over multiple microphones, music sources or other audio equipment. For straightforward systems, compact mixers such as the Yamaha MG06 provide the controls required without making the setup unnecessarily complicated.

Larger presentations, conferences and functions involving numerous wireless microphones require appropriately configured mixing systems. Audio Hire's multi-channel wireless lapel and headset microphone system, for example, combines its receiver channels through a rack mixer so multiple presenters can be controlled independently.

If you're hiring a PA and aren't sure how much mixing capability you need, tell us what you're connecting and how the system will be used. We can configure the equipment around the application and explain the setup so you're not paying for — or trying to operate — a mixer that's more complicated than the job requires.