Bringing audio projects to life for an audience all starts with an idea or two.
You might want to broadcast a live podcast. Or maybe you play in a band and want to be able to handle your own sound. Heck, you could be ready to put on your audio engineer’s hat and run sound for musical groups and events in performance spaces. Think of the possibilities…
But before you start your incredible recordings, you’re going to need an audio mixer.
The thing is… there are a lot of mixers out there. And all of them have different shapes, sizes, and form-factors with various feature sets.
So, where do you start?
The first thing to consider when determining which mixer to purchase is to look at the number of input channels.
What’s an input channel on a mixer? It’s basically a section that captures audio signal from one specific source —– such as a microphone, guitar, or directly from an electronic device.
More inputs mean more possibilities and added features elsewhere on the mixer! But that doesn’t mean you need to go find the mixer with the most inputs and mortgage your house for a downpayment. Depending on your needs, you might not need more than one or two channels — or maybe you do… It all depends on your individual recording needs.
There are more things to look for besides the number of inputs – such as analog or digital, recording capabilities, wireless functionality, the number of outputs for signal paths and monitoring, and design form factor. But starting with the number of inputs here builds a foundation and is first on the checklist for finding your ideal mixer match.
What do you want to record?
The number of inputs you need on a mixer is directly related to what you want to record or engineer. Naturally, if you want to record a full eight-piece band, you’ll need more channels than a simple one-person singer/songwriter setup.
Listed below are different instruments and audio sources used in common music and performances, how they can be added to the mix, and how many mixer input channels they require. Once you add up the totals, you’ll get an idea of how many channels you’ll could be dealing with and what mixer will best suit your needs.
Vocals
Requires: One Mono Channel
Each vocal microphone uses one mono channel.
Plug in a handheld dynamic microphone, and you’re ready to start setting your levels. Dynamic mics are regularly used for live performances due to their rugged builds and ability to handle loud vocals. Sound waves hit a coil surrounded by a strong magnet, and the resulting movement within the coil generates a small amount of voltage that is converted into an electrical signal. They don’t need any external power to operate.
Condenser microphone diaphragms require phantom power from the mixer in order to operate, which is supplied through the connected XLR cable. Condenser vocals mics are more sensitive to signal and capture nuanced details and specific sonic characteristics more accurately. They are more commonly used in recording applications, but also have their place during live performances as well. There are Large Diaphragm Condensers and Small Diaphragm Condensers, each with a different set of uses for vocals (as well as instruments and ambient sound pickup).
NOTES: Mixers either have a general control switch that supplies phantom power to all input channels OR they have specialized switches for each individual channel.
Make sure to mute the mixer channels and outputs before you turn phantom power on or off - this prevents undue stress on the speakers. Plus, you won’t scare everyone in the venue with the resulting loud pops from the PA! Don’t unplug the mics while phantom power is still on and wait about five seconds after switching phantom power off for the current to discharge.
The majority of dynamic microphones are not affected by phantom power, but specialized ribbon microphones and many vintage microphones can be damaged if improperly powered. Always, always, ALWAYS double-check the specs of your mics to make sure.
Guitar and Bass
Requires: One Mono Channel per Instrument
The most common solution is to mic the guitar combo amp, bass combo amp, guitar cabinet, or bass cabinet directly. This way, you can balance the sound of the amp on stage with the sound coming out of the main PA speakers to achieve an ideal volume. Acoustic players that don’t have any electronics in their instruments should have a mic aimed close to the lower part of the fretboard, between the sound hole and the top of the body.
In many venues, the stage volume of an amp is going to be plenty strong, so you’ll need little to no instrument sound in any of the stage monitors. You might need to put guitar or bass in the monitor if the band is spread out across a wide distance on a very large stage or if they’re playing at an outdoor venue.
If the electric (or acoustic-electric) guitar or bass player doesn’t have an amp, you have two choices:
First, you can plug the instrument’s 1/4” instrument cable (unbalanced) directly into one line input on the mixer. Look for a channel that has a ‘Hi-Z’ control switch; you’ll need to activate that in order to boost the guitar or bass instrument-level signal to the proper line-level signal. Instrument cables are meant to be used close to the amplification source, so only use this option if you are less than 15 feet from the mixer or stage box.
Second, you can connect to a Direct Box (or DI). Simply plug one end of a 1/4” instrument cable into the Direct Box input. Then you plug an XLR cable in the Direct Box output and run that to the mixer/PA system. This converts the unbalanced signal to a balanced one, allowing you to stretch the connection over much greater distances. Going to a DI is best for long cable runs.
There are two types of DIs: Active Direct Boxes (which require phantom power) and Passive Direct Boxes (which don’t require any power). As a rule of thumb, if the instrument/device source is actively powered (like a digital keyboard), a passive direct box is recommended. If the source is passive (like an electric guitar), go with an active direct box.
Keyboard
Requires either:
- One Stereo Channel with 1/4" (Direct Line Input)
- Two Mono Channels, one panned right, the other panned left (Direct Line Input OR through a Stereo Direct Box using XLR)
- One Mono Channel with XLR (Mic’ing the Amplifier)
Digital Keyboards, Digital Stage Pianos, Synthesizers, and other electronic gear pieces like Samplers and Drum Machines have line-level stereo outputs. You can plug the outputs directly into the mixer or plug a direct box for longer cable runs, just like you would with an electric guitar or bass.
NOTE: It is common to run keyboard sound in mono by only using the left side of a keyboard’s stereo output, in which case you’ll only need one mono channel.
Just like guitar and bass, many keyboard players will often use their own keyboard amplifier. In that case, it’s common to mic the amp, which would require one mono channel.
Woodwinds and brass
Requires: One Mono Channel for each instrument
Each microphone for a horn player uses one mono channel. As with vocal mics, plug in a dynamic instrument microphone and you’re ready to start setting your levels. Some horn players prefer condenser microphones which will require phantom power from the mixer.
Acoustic drum set
Requires: Anywhere from one mono channel to eight or more.
If you are mic’ing a drum set, the requirements can range from just a couple of channels to eight or more. For certain mixer models, that could mean over half of your available channels!
Drums take the most time to set up and tear down, and the same is true when it comes to mic’ing them.
The most basic setup in a smaller venue would be to simply mic the kick drum (one mono channel), which brings out the low-end rhythmic punch. A standard-sized or larger venue might require a bit more – such as a mic for the kick drum (one mono channel), snare drum (one mono channel), and a pair of overhead mics to cover the remaining drums and cymbals (two mono channels).
For the biggest spaces and outdoor venues, or if you wanting to record the live performance in multitrack, you’ll need a microphone (one mono channel) on each part of the drum set:
- Kick Drum
- Snare Drum
- Floor Tom
- Mounted Tom(s)
- Hi-Hat
- Cymbals (two mono channels for a pair of overhead mics)
It’s important to remember the sound of a drum set carries strongly on stage and out into the crowd, so you don’t want to add extra unnecessary volume through the PA.
Many live music performance spaces are built with plenty of metal, concrete, stone, and exposed wood beams in the ceilings, floors, and walls – materials that naturally reflect and amplify sound. There’s is often minimal sound deadening material or acoustic treatment in many music space, so it’s important to listen to the reverb, frequency distribution, and tonal colors naturally generated by the venue itself as you prepare to mic and mix.
Electronic drums
Requires either:
- Two Mono Channels for the master stereo mix of the entire drum set, one panned right, the other panned left (Direct Line Input from the module device OR through a Stereo Direct Box using XLR)
- One Mono Channel for EACH individual drum/cymbal (Commonly 4-8 Direct Line Inputs from the drum module)
- One Mono Channel with XLR (Mic’ing the Amplifier)
Think of mixing an electronic drum set as a combination of both a keyboard and an acoustic drum set.
Each part of an electronic drum set is connected to a main module. The module has a master stereo output for the entire set – from there you can either go directly into a stereo input on the mixer or use a Stereo Direct Box (two mono channels, panned left and right) when a long cable run is needed.
There are also modules with dedicated solo outputs for each part of the set (kick, snare, tom, hi-hats, etc). Each of these would require one mono channel. Choosing this method gives you more control over individual levels during live performance and multitrack recording.
Many performers playing electronic drums may also have their own drum amplifier, in which case you can choose to simply mic the amp using one mono channel.
Laptop, computer, tablet, or smartphone
Requires either:
- One Stereo Channel with pair of 1/4" cables (Direct Line Input)
- One Stereo Channel through Bluetooth (if supported by both the computer/device and the mixer)
- Two Mono Channels, one panned right, the other panned left (Direct Line Input OR through a Stereo Direct Box using XLR)
Laptops, tablets, and smartphones have become a popular mainstay for bands —- used to add click tracks, fully produced backing tracks, or as instruments themselves to trigger samples, create soundscapes, or add additional audio textures.
Computers have a stereo output, most commonly in the form of a 3.5mm headphone output. Newer models of tablets and phones have been ditching the headphone output, so you’ll need an USB-to-3.5mm headphone adapter (or similar) from your phone’s manufacturer for a wired connection.
Like keyboard and sampler instruments, you can connect directly to the mixer (if you go this route, you’ll need a Stereo 3.5mm-to-1/4” Stereo Pair Y-Cable or go through a Direct Box for longer cable runs).
Most computers and devices can also use Bluetooth, so if your mixer also has Bluetooth capability, you can utilize a stereo channel that way.
Performers using software for live laptop performances often use an audio interface to maximize their computer’s processing power and provide extra connectivity options. Audio interfaces commonly have either 1/4” or XLR outputs.
The Radial Trim Two Direct Box is a wonderful DI for DJs and laptop performers. It gives you the connections you need, providing balanced signal whether you’re going from the computer/device directly or from an interface.
Odds and ends
Running live sound is always going to be full of unexpected twists and turns. That’s why it’s important to have a couple of extra channels open and available, just in case. Some examples:
- A spur-of-the-moment request for an audience member to come up and sing backup vocals for a set.
- The keyboard player unveiling a new synthesizer, much to the surprise of the band (and the sound engineer).
- A band member’s vintage string instrument – refurbished DIY-style – has a now-busted homemade pickup due to faulty wiring and isn’t working as it should.
- A horn player wants to add effects to their instrument and control when they are triggered, so they bring out their pedalboard with direct stereo outputs.
You’re going to see a lot of surprising requests and need to be ready to alter your mixing plans. That could mean using an extra channel, changing an input source, or incorporating an extra device (such as a DI) to accommodate for sudden changes.
How many channels do you really need?
Now that you know how many channels each instrument or mic source needs, it’s time to add up the totals based on what you use or see yourself needing to accommodate.
For smaller-scale events, like mic’ing podcasts, solo music projects, or minimal 2-3 person bands, a mixer with 8 or 12 channels will cover your needs.
A 16-channel mixer can handle a 4-5 person band that includes a drummer, but if you max out microphones for the drum set, you’re going to find yourself using up all of those inputs in a hurry.
So, if you’re planning on running sound regularly for a variety of larger bands, you should go with a mixer that has at least 24 input channels.
The largest consoles (32+ input channels) can handle the biggest live music performances and production projects, like bands with eight or more people, each playing multiple instruments; chamber orchestra groups and choirs; shows that need multiple amplification sources and perspectives, such as multiple pairs of general overhead mics from different angles, channels for both direct instrument signals, and mic’ed amp cabinets; mics for audience noise; and so forth.
Once you get past 16-channel consoles, increasing size and weight become a factor. If you plan to travel and do sound on location, be sure to check out a mixer’s specs, dimensions, and weight. A Mixer Case and storage for microphones, cables, adapters, and additional hardware are a must when taking any rig on the road.
The larger console mixers (32+ channel) are more commonly used as part of a fixed installation for a studio or music venue. You can still transport them, but you’re going to need at least one other person to help you move it around and plan for plenty of room in a vehicle or trailer.
An alternative would be a digital rackmount mixer, which can pack a large channel count into a space-saving portable rack case and can be managed through an app or browser using a tablet or smart device. Adjust levels, add effects, take care of stage monitoring, and craft your overall mix wirelessly through a network.
Find your perfect mixer at AMS
So, how many channels do you need? It all depends on you - what kinds of live performances you’ll be running, what you want to record, and what your exciting musical plans are for the future. With this information, you now have the idea of the requirements needed for mics, instruments, and gear and how it relates to a mixer setup.
American Musical Supply has a wide selection of mixers from the most popular brands in the business. Enjoy 0% interest payment plans as well as fast and free 2-day shipping on practically everything. Their 45-day return policy allows you to buy with confidence and know that you’re getting the right mixer for your needs. Order today and in-stock mixers will ship right out - you will be able to get started creating and performing new music right away!