(When) Do I Need an Audio Recording Mixer for My Home Studio?
An early thrill of walking into a recording studio was, for me, the sight of the big studio mixer board. A huge table filled with knobs, faders, meters, it got me stirred up just looking, even before I knew what the heck it really did. Recording studio mixers grew a little less intimidating once I realized that this vast array of controls broke down to relatively small sections that were repeated again and again. I had only to learn a narrow strip of real estate. Next to it was another mixing console, with all the same controls, then another, and another, on and on.
The Best Mixer for Home Studios
The thing about mixers is that they are a sort of facilitating device. In themselves, they are not actually native to recording or live music. When recording began, there was no mixer. There was a single microphone connected to a wax cylinder. Later, a disc cutter replaced the wax cylinder, but still the single mic was the input. Balance was achieved by telling Charlie he was too loud and asking him to step back from the mic.
Live music was the same. Band shells had no electricity at the turn of the 20th century. Later, once electric guitars became the rage, a club gig was played through amps with a drummer just making his usual ruckus without a dozen mics on the kit. If there was a mic at all, it would be plugged into another amp, and often it shared an amp with a guitar. As the Beatles started inventing the stadium concert, there were only the most rudimentary PA systems. No wonder screaming girls could drown them out.
The point behind this is to de-mystify the mixer somewhat. Because of its apparent complexity, the mixer has become something of a studio touchstone. As with so many things, the idea of a mixer has come to something resembling a full circle. It’s just not 100-percent necessary to have one in a home studio.
Recording Mixer Vs Audio Interface
While it’s not necessary to have a standalone audio mixer, it may well be advisable. As with so many things, the best methods depend on a balance of answers about your project such as:
- What is the target of your finished product?
- What equipment do you have on hand?
- What kind of budget do you have to work with?
In some cases, a hardware mixer isn’t needed. In others, a recording project may be all but impossible without one. Let’s take a look at some mixer basics and then a number of typical projects and how the presence of a mixer affects each.
Home Studio Recording Mixer Audio Signal Chain
Signal chain is simply a way of describing how sound gets from point A, a microphone or other sound source, to point B, speakers, headphones, or earbuds. In essence, that’s the recording process. In its simplest form, it looks like this:
Pretty simple, however there are some practical matters. The electrical signal coming from the microphone is quite small. In fact, it’s pretty much useless to us as-is. Before we can do anything here, we need an amplifier, a pre-amplifier, if you will, to take that weak signal and boost it to a useful level. So adding that, our signal flow looks like this:
So, preamps, where do we find them? You guessed it. Mixers have them. However, that’s not the only place you’ll find them. You can find these as stand alone equipment and as part of a digital audio interface.
To learn more about preamps, check out my my Preamp Guide.
Now, the preamp in the chart here is directly connected to the speaker. This won’t do anything except leave you looking at the speaker, wondering why it’s quiet. The mic signal is bigger, but not big enough. Just before the speaker in the signal chain, there is another amplifier, expressly for driving the speaker. It’s not really part of our mixer discussion, but you should know it’s there. Many home studio monitors have the amps built right into the speakers, so for purposes of this article, we will consider the speaker power amps are that sort.
Since we are talking about mixers in this article, let’s consider just two configurations, to help keep me from confusing myself. It is surprisingly easy. These are the most common configurations of preamps in an average home studio.
Preamp on a mixer
- Most mixers are laid out in channel strips that run from the top of the mixer down to the bottom, or in desktop terms, the side away from you to the side closest to you. A typical channel strip might have the mic input, gain control, EQ (usually two to four knobs), auxiliaries, panning and a level knob or fader, top to bottom. There can be many more controls for routing and dynamics, but most conventional mixers contain these basics. This is the mixer’s playground. You can set the preamp gain for a good audio level. EQ changes the relative level of different bands of frequencies to fine-tune the sound. Panning sets the position of the signal in a stereo mix, left to right, and the level fader sets the volume of the signal compared to other channel strips. Then everything gets sent to the Master section where it is combined and output. There’s a lot you can do with this stuff on a mixer.
- The mixer can take the place of the yellow preamp box in our signal flow chart. While you can now probably plug headphones into the mixer (which you could also do with a stand alone preamp), the mixer still can’t drive the speakers. And since we are recording, there’s nothing in our signal path that addresses that.
Preamp in an audio interface
- An audio interface has far fewer controls, but then it has a more specific job to do. Most interfaces have gain controls for the preamps, same as the mixer. There may be a few routing controls, but these are different than a mixer. They’re bi-directional, for a start. A conventional mixer is a one-way device. Mic in, signal out. An interface does that too, mic in, signal out, connected to a computer or other device, most commonly via a USB mixer interface. The bi-directional part means that that there’s also signal coming back from the computer to the interface. That gets sent along to our speakers.
- The interface also converts analog audio into digital audio. The playground isn’t with the interface, as it is with the mixer, it’s with the computer. All of the playthings on the mixer are available in digital audio workstation software. You could call a DAW “mixer software” but that is kind of limiting, since a DAW package will record, mix, sequence, control virtual instruments and master, much more than a mixer can do on its own.
If it sounds like the interface is a much simpler and effective solution, in many cases, you’re right. Let’s compare the complete signal chain for each of these examples. Note that the Interface has both an input and output role. That’s the bi-directional part. The signal goes out and comes back through the USB cable:
Given how smart you are you saw this coming. The mixer is really an extra step. Most of the things it can do, the interface and computer can also do. Seems like the mixer is really not needed.
Or is it?
This is where the goal of your project comes in. It may dictate what you need in the way of equipment. And of course, it’s the computer age, so nothing is so straight-forward that I can flow chart all the alternatives. Wouldn’t it be great if you could have a mixer that is also an audio interface? Of course it would be great, and USB mixers have been around for about a decade. Time to look at some projects: the goals, the people and the equipment. We will look at three different projects. At last count, there are exactly 4,733,581 ways to create audio projects, but I fell asleep while I was counting, so it’s possible I missed one. The point is, don’t freak if your project doesn’t fit one of these scenarios. Boundaries will cross.
Project #1: Karaoke Voiceover
A professional recording of a singer over a pre-recorded backing track.
Technical novice to intermediate, comfortable with some basic audio routing and familiar with DAW software
No. A basic audio interface will suffice. This could be a standalone audio interface or a USB microphone. A USB mic is an interface built-in to the mic, another one of those amazing bits of combined technology. You can get USB mixer interfaces under $50, such as the Behringer Mic2USB or the Lexicon Alpha. For $100 USB audio interface mixer solutions, look to devices like the M-Audio M-Track 2×2 or PreSonus AudioBox USB. USB microphones (Like the Blue Yeti Pro (Review) provide an even more cost-effective solution, as you can get a microphone and interface anywhere from $40 to $400. Keep in mind that a USB mic may not be much good to you if you plan to play gigs as well.
HOW IT WORKS
- The pre-recorded track is downloaded or ripped from a CD and placed on a stereo track in the DAW software.
- A mic is connected to the audio interface, which is in turn connected to a computer.
- The vocal is recorded onto another track in the DAW software and subsequently mixed in the DAW with the pre-recorded track.
- Stereo recording a singer-songwriter or live performance. See the Hear the Music article, “How to Record an Acoustic Guitar” for practical information on the process.
- Building a track-by-track recording through overdubbing one instrument at a time
Project #2: 5-Piece A Capella Group
Record and mix five singers performing contemporary vocal music.
Intermediate to Experienced, able to handle multiple microphones, cable routing and possibly headphone feeds for the performers.
Yes. Contemporary vocal music often includes beat-boxing and other unconventional vocal sounds that require mics to create effectively. This rules out a single or double mic recording technique. A mixer with at least 5 XLR inputs will be needed to record the entire group in one pass. While each singer could be overdubbed individually, capturing the interaction of the group will be difficult, if not impossible.
Mixers suitable for this task include: the Behringer Xenyx 1002B, which offers 5 XLR inputs for $100; the ART MX821S rack mixer, with 8 XLRs for $185; or the Soundcraft Signature 10 at $300, with 6 XLRs and USB playback and recording. There are many, many mixers out there, usually defined by the number of XLR preamps included.
HOW IT WORKS
- The singers’ mics are routed to the mixer and balanced on the mixer to create a stereo mix, which is recorded through the audio interface or the mixer’s USB connection, if available, into the DAW software.
- The mixer’s headphone output or channel auxiliaries may be used to create and supply monitor mixes for the singers.
- The stereo recording is then altered inside the DAW software to create the final recording.
Any recording project with more than two sound sources, being mixed to two tracks for recording.
PROJECT #3: FULL MULTITRACK ROCK GROUP RECORDING
Recording a 4-piece rock band playing together in a studio. The recording will capture each instrument and voice on its own track in the DAW software
Intermediate to Experienced, able to handle multiple microphones, advanced signal and cable routing, mic isolation and headphone feeds for the performers.
Yes. As well, to capture more than two tracks, not just any mixer with enough inputs will do the job. We need to consider outputs also. Looking at the band, we decide we need the following:
- Four drum mics, mixed in stereo = 2 tracks
- One guitar amp mic times two guitarists = 2 tracks
- One track for the bass, which is being recorded through a direct inject box = 1 track
- One mic for vocals (harmonies will be overdubbed) = 1 track
That’s six tracks in total. Most mixers have a stereo master section, or two tracks, for output. Since we need to record a minimum of 6 separate outputs, we must make some other arrangement here.
HOW IT WORKS
Some USB mixers now make the job very easy. Instead of 2 tracks in and out of the mixer through the USB connection, that cable now handles all the multitrack audio the mixer delivers. Mixers such as the Allen & Heath MixWizard WZ4 16:2 can be upgraded so that all its channel strips are sent via USB to the computer running the DAW software. PreSonus will release a line of mixers with this capability included later in 2017. Behringer’s X18 is another blend of technology that uses a tablet as a control surface and routes each of its inputs to both main outputs and to a software DAW via USB. Each of these mixers is a one-stop solution. No extra audio interface needed.
To record multitrack with an analog mixer and an audio interface, the interface must first be able to handle 6 input channels simultaneously. For that capability, you’ll need an interface along the lines of: Behringer FCA610 at $200; Focusrite Scarlett 6i6 at $250; or the MOTU Audio Express at $400. Each handles 6 input channels.
Most mixers have the stereo main output, or two channels. That leaves us four short, but the really nice thing about analog mixers is that most have several ways to accomplish a job. Here’s a quick look at how various mixers can provide 6 simultaneous outputs to feed the multitrack interface:
- Buses – a stereo mixer could be called a 2-bus mixer. Left and right channels are its two buses. So a 4-bus mixer adds two stereo sub channel pairs to the main output. Each strip can be assigned to one of these three pairs. Three pairs, or 3×2=6.
- Auxiliaries – most compact mixers only have a couple Aux sends, but it’s possible to find 6 or even 8 Aux sends. In live situations, these would be used to provide 6 different monitor mixes to the musicians, all of whom want “more Me” in their mix. Each Aux send is like a little mixer. Connect each of those to an interface input, and you have signal for recording.
- Channel inserts/Direct outs – Though the wiring can be tricky with channel inserts, these and channel direct outs are another source to gain additional signals to send to the multitrack interface.
This is kind of the full bore. There’s not much different about Project #3 and a commercial recording studio except scale.
USING MULTITRACK USB INTERFACES ALONE
Since interfaces can now handle multitrack inputs, you may still question the need for a mixer. In this primer, we haven’t even discussed digital mixers which are even more versatile than analog in some cases, but which do not offer a standard way of working. Every maker has their own system.
What about plugging mics directly into a multitrack interface? It can be done, and as the Behringer X18 shows, the boundaries between interface and mixer are changing. However, the versatility that a mixer offers in multitrack situations isn’t yet matched by an audio interface system that’s affordable for a home studio.
(When) Do I Need an Audio Recording Mixer for My Home Studio?
A recording mixer interface is not always required in a home studio, but when it is, it usually earns its keep. Besides just passing an audio signal to the interface, you can modify that signal with EQ. You can balance it with other signals also going through the mixer. In fact, studio engineers were once called “balance engineers” for that very reason. If your home studio mixer has built-in effects, you can add those to your sound before recording. Be careful, there’s no going back if you choose that method, but it can be a way to create new sounds.
There’s something about the tactile act of touching knobs and faders to manipulate your music that is inherently pleasing. It’s something that software mixers don’t offer. The routing and versatility that a recording studio mixer offers at the front end of the recording process can be invaluable with more complex sessions. On the flip side, if signal paths hurt your head, there’s nothing that says you have to use a studio mixer board. It’s nice to have optional tools sometimes.