When you look at an audio mixer, it can be kind of intimidating. However, as you'll see in this video, it's a lot less complicated than it looks. Right here I've got the Mackie ProFX 12 V3 Plus, but what I'm about to teach you can be applied to almost any mixer on the market. Thanks to Mackie for sponsoring this video and supporting audio education. Most analog mixers will have the same basic layout. There are inputs for connecting to sources, such as microphones. Each input has its own line of controls called a channel strip. And over here, there are outputs for connecting to destinations, such as speakers or recording devices. You can use a mixer like this for anything from live streaming and podcasting to recording music or running live sound at an event. For the sake of understanding the features and controls of a mixer, picture this scenario. You and I are running sound for an event with live music. The system includes two powered speakers for the audience and one powered stage monitor for the performer. The musician on stage will be singing and playing acoustic guitar and will record the performance to a laptop. When the musician is taking a break between sets, we'll play background music from a tablet. Let's look at how we can set all of this up on the mixer. We can start by connecting the outputs to the speakers. The main speakers for the audience will be connected using the main outs. We can use an XLR cable from main out left on the mixer to the input of the left speaker and another XLR cable from main out right on the mixer to the XLR input on the right speaker. This mixer gives us the option to use either XLR or TRS, but you can always use an adapter. XLR and TRS are basically the same connector. The adapter you'll need just depends on the type of connections on the mixer and the speakers. The main outs are controlled by the main fader. This is commonly called the master fader and it can almost always be found in the bottom right hand corner of the mixing console. You can think of the main fader as the volume control for the main outs. You'll find a mute button just above it that mutes everything coming out of the main outs. In a moment I'll show you how to route our input sources to the main speakers, but first let's set up a stage monitor for the performer so they can hear themselves play. We can set up a stage monitor using an auxiliary output such as the monitor send on this mixer. In this case we only have a quarter inch output, so I'll use a quarter inch TRS to XLR adapter and a long XLR cable to the input on the powered speaker. Similar to the main outs being controlled by the main fader, the monitor send output is controlled by the aux master knob. Next we need to set up the recording. There are a few ways to do this. One, we could connect the mixer directly to laptop via USB and record directly into a DAW using the built-in audio interface within this mixer. In standard mode this option would record the signal that's sent to the main fader. Or option number two, we can connect the sub one and two outputs to the inputs of a standalone audio interface using TRS cables. Let's go with this option because you may not always have a mixer with a built-in audio interface. You're probably starting to see that each of the physical outputs on the mixer is controlled by a dedicated knob in the master section. The sub one and two output fader controls the level of the sub one and two output. There's one more very important output we want to set up, the phone's output. The reason a headphone output is so important is that it allows us to check the audio before the audience hears it. Right here is the headphone jack and that's controlled by the phone's knob. Now that we've connected the outputs of the mixer to the destinations, let's connect our sources. Remember the inputs include vocals, acoustic guitar, and background music. I always start by testing the system with music from my smartphone or tablet and this mixer offers a few different ways to do that. With channels 11 and 12 we can connect via Bluetooth or with an eighth inch aux cable. For this demonstration I'll connect my tablet via Bluetooth and start playing some music. We don't hear anything yet though. This vertical line of controls is called a channel strip and at the bottom of each channel strip we see a channel fader and a couple of buttons. One of these buttons is the PFL solo button. PFL stands for pre-fader listen which means that what we hear when we press this button will not be affected by the position of the channel fader. Pressing the PFL solo button will send audio from channels 11 and 12 to the phone's output and now I can hear music playing from the tablet through my headphones and I can see levels on the meter. Based on this meter I'm going to adjust the output level of the tablet. We're going to aim for peaks to be at or just above zero dB. Here have a listen. Okay the music sounds clean and the headphones so now I'll disengage the solo button. Now we can bring up the music and the speakers. First we need to unmute channel 11 and 12 then we need to select which output to send it to with these routing buttons. The one and two button sends the signal to sub output one and two which is currently connected to the audio interface for recording. We don't want to send the background music to the recording so let's leave the one and two button disengaged. The LR button routes the signal to the main output which is connected to the main speakers where we want to hear the music. So let's press the L and R button. Now when we push up the channel fader it will send the signal from channel 11 and 12 to the main mix. However the main fader is currently pulled all the way down and the mute button is engaged. If we want to hear something through this output we need to unmute the main and bring up the fader. We can bring up the 11 and 12 fader and now we hear the music start to play out of the main speakers. Okay let's pause the music. Before going any further we need to adjust some levels. If the music is extremely loud even when you slightly bring up the 11 and 12 channel fader we should probably turn down the volume of the amplifier or powered speaker. Ideally the music in the room will be at an appropriate level when the main fader and the channel fader are at the zero dB mark also called unity gain or U for short. If needed you can pull down the main fader to accomplish this but it's better to keep the main fader at unity and adjust the amplifiers especially in extreme cases. As you become more experienced you'll understand that this rule is made to be broken but I think this is a useful guideline for beginners. There are a couple of reasons why we want these two faders to be at or around unity gain. The first is to utilize the full dynamic range of the mixer. We test the system with mixed music at an appropriate level on the meter so that we can get an idea of how loud our mix will be in the room during the show. The second reason to keep faders at or around zero dB or unity gain is that the fader scale is not linear. A small movement in the shaded area will result in a relatively small change in level compared to a small movement down here at the bottom. So keeping the fader at unity gain allows us to make subtle adjustments much more easily. If this mixer didn't have bluetooth or eighth inch connectivity we could have also used channel 9 and 10 with a eighth inch to dual quarter inch adapter. You may be wondering why the channels so far have been labeled in pairs such as 9 and 10, 11 and 12. The reason is that these are stereo channels which facilitate the stereo left and right audio channels of the music. Next we need to connect the vocal microphone and acoustic guitar which will each be mono inputs. Let's connect the vocal microphone to input 1 using an xlr cable. We'll assume we're using a dynamic microphone like this one which doesn't need phantom power but if we were using a condenser microphone I'd engage the 48v button right over here. The acoustic guitar could be miked up with another microphone but in this case let's assume it's an acoustic electric guitar so we can connect the built-in guitar pickup to input 2 using an instrument cable. Because input 2 is connected to an instrument directly I'll press the high Z button to put this channel into high impedance mode. By the way using an instrument cable is fine up to about 15 to 20 feet but if you need to run the signal over a longer distance check out my video on DI boxes linked in the show notes below. Once the vocal microphone and guitar are connected to the mixer the next step is to check these sources in headphones. Again we do this by pressing the PFL solo button at the bottom of the channel strip. As you can see the signal level is very weak on the meter. We need to boost the signal level using the preamp gain at the top of the channel aiming for peaks at or around 0 dB. Side note this mixer has an analog level meter. That's why it's okay if the signal peaks go beyond 0 dB but if we were using a mixer with digital metering or full-scale metering the 0 dB mark would be at the very top of the meter. In that case clipping would occur at 0 dB so we would actually aim for levels that hover around minus 12 or minus 18 dB to give the signal some headroom before clipping. Now that we've verified a clean signal we can un-solo channel 1, we can unmute it, assign it to the main bus with the LR button and bring up the fader. Okay let's mute that for now. While we didn't want the background music from the tablet in the recording we do want the vocal mic in the recording. To do that I'll also send channel 1 to sub 1 and 2 by pressing the 1 and 2 button. Remember we need to unmute sub 1 and 2 and bring up the fader in order to hear anything. Once we have channel 1 set we can mute it and go on to channel 2 to do the same thing with the acoustic guitar. We check the audio first in headphones using the PFL solo button. We set the input level aiming for peaks at or just above 0 dB. Then we un-solo channel 2, assign it to the main mix using the LR button and assign it to the sub mix which feeds our recording with the 1 and 2 button. Unmute the channel and bring up the fader. Okay once that's dialed in I'll go ahead and mute the guitar channel as well. At this point we hear each input source in the speakers but it may not sound very good just yet. Let's look at the other controls in each channel strip. First notice that all of the channel strips are more or less the same depending on the type of input. This means that you just need to understand one channel strip in order to understand all of the channel strips. At the top of the channel strip we see the high Z button. We've already learned that this is for connecting high impedance to the high Z. We'll leave this un-pressed on the microphone channel but because we do have a high impedance source on channel 2 we go ahead and press the high Z button. Just below this we see the insert connection. Let's return to that in a moment. Next is the low cut button. When this is pressed the lowest frequencies below 100 Hz in this case will be attenuated or reduced. The human voice doesn't have much information below 100 Hz anyway so engaging this switch will remove unnecessary low frequencies without really impacting the sound of the vocal signal itself. The same goes for the acoustic guitar on channel 2. Engaging the low cut is particularly useful in live sound where low frequencies tend to feedback very easily through the speakers. [Music] We've already set up the preamp gain for each input so let's continue on to the compressor knob. A compressor can be used in many different ways. One thing you can do with compression is smooth out the dynamic range of a performance reducing the difference between the loud parts and the quiet parts. The more you turn up this knob the more the compressor keeps the loudest parts in check. This might be helpful for smoothing out the vocal or the guitar. We just need to listen and adjust accordingly. [Music] Keep in mind compression can be very subtle and kind of difficult to hear if you're not trained for it. Just keep practicing and you'll get a hang of it. As we move further down the channel strip we reach the EQ section. This mixer has a three band EQ with high, mid, and low. You can boost or cut the specified frequencies with the corresponding knobs. The frequency of each band is fixed on this particular mixer however you may come across mixers such as the Mackie ProFX 16 V3 Plus with a variable frequency control that allows you to specify the frequency and specify how much to boost or cut it. I generally recommend cutting versus boosting when possible. If the vocal sounds muddy for example I could either boost with the high band or cut with the low band. [Music] The compression and EQ settings are completely dependent on the situation and sometimes you'll use no compression or EQ at all. In fact it's much better to not use compression or EQ than to use compression or EQ for no reason. So use your ears and adjust accordingly. Below the EQ section we reach the aux send knobs. The monitor knob determines the amount of each channel to be sent through the monitor send output which currently feeds the performer's stage monitor. Again we need to turn up the aux master knob in order to hear anything through the stage monitor. In this case Unity Gain is about 50% and there's a detent in the knob when it reaches that position where the knob locks into place to let me know that that's the default setting. We'll set the monitor aux send knobs on both channel one and two to provide the performer with a comfortable mix of vocal and guitar in their monitor. Let's listen to what the musician on stage is hearing for just a moment. [Music] The effects knob below could be used as a second monitor send if we had two musicians on stage who needed different amounts of each source in their stage monitors. That signal would come out of the effects send output just below the monitor send output. But in this case we'll add some reverb on the vocal and guitar using the effects send. First we need to unmute and bring up the fader on the effects return channel. Then we can use the effects send knob to apply reverb to each channel. [Music] If you had an external reverb unit the signal could be sent out of the effects send output into the input of the reverb unit and then the output of the reverb unit could come in on separate channels either mono or stereo as an effects return. Here the reverb is built into the mixer itself but the signal flow is essentially the same. Send with the effects send return on the effects return. You can experiment with sending more from the send and coming back with less on the return or sending less with the send and bringing more in with the return. We can also add some reverb to the monitor with this effects to monitor. So again let's listen to what the musician's hearing on stage. [Music] I'd usually use a subtle amount of reverb in the mix but just so you can hear what's happening at home. Let me put a lot of reverb on this. [Music] And if we want the reverb in the recording which we do we can press the one and two button on the effects return channel. The next knob on the channel strip is the pan knob. With stereo left and right speakers or stereo recordings this knob controls where the input is positioned in space. [Music] Turning the knob all the way to the left puts the signal only to the left main out and the left sub out. [Music] Turning the knob all the way to the right sends this input channel only to the right main out and the right sub out. With the pan knob in the center the signal will be routed evenly to both the left and right channel of our stereo mixes. And now we've reached the fader which can be used to create a good blend between the different channels. This control can be used throughout the show when the level of an instrument needs to be adjusted. Before I forget let's get back to the insert connection at the top of the channel. This is the connection you would use to insert a piece of external hardware into this channel strip. While we typically integrate a reverb or echo effects processor by sending the signal out to the unit and then back in on a separate channel we will typically integrate an external EQ or compressor by sending out through the device and back in on the same channel. You set this up using an insert cable like this one. It's got a TRS on the mixer end and two TS on the other end. One input and one output. Throughout the process of setting up your mixer you may encounter problems with microphone feedback. In the next video I'll share with you a few tips to eliminate microphone feedback so it doesn't ruin your show. Go ahead and click that link and I'll see you over there.
