Buying DJ equipment can be confusing. There are many different pieces of equipment you’ll need, and it not only has to be compatible with each other, but the specifications vary depending on the size and location of the audience you intend to perform in front of. It can be very overwhelming, so it’s important to start with clear definitions.
Is a DJ mixer an amplifier? No, a DJ mixer controls how much of which audio signals from the various possible inputs are sent to the speakers. An amplifier takes the relatively weak signal that comes out of the mixer (about one tenth of a watt) and amplifies it to the hundreds of watts needed to power loudspeakers.
Sometimes amplifiers are built into mixers or speakers (making them powered mixers or powered speakers, respectively), but even a powered mixer is not an amplifier. It is just two pieces of equipment housed in one unit. Taking a closer look at what DJ mixers and amplifiers are will further clarify their differences.
What is a DJ Mixer?
A mixer acts like a junction box for sound. Audio comes in through the inputs from various sources, such as turntables, CDs, or your laptop. The mixer controls the quality and levels of these sounds, then sends the signal out to the speakers.
A DJ mixer in particular usually has only 2 (some models have 4) input channels. It offers unique features like a simple crossfade slider to blend inputs and the ability to send a separate mix to your headphones so you can mix the tracks before playing it for the crowd.
DJ mixers can accept audio from many different sources, but these sources all have different types of connectors and send the signal differently. The back of the mixer, therefore, has inputs that can connect to turntables, CD players, computers, and more. There is one of each type of input for each channel.
The different inputs accept different types of signals. Phono, for example, is designed for vinyl turntables because they have a relatively weak output. Line in inputs are for digital inputs like laptops. It’s essential to connect your audio source via the appropriate input for this reason.
Because each channel can accept audio signals via many different inputs, the input switch simply selects which input the channel will use.
Gain (or Trim)
The gain allows you to control how much of the incoming audio is allowed into the channel. Some records, for example, may play quietly, and you need to turn the gain up to hear them better, while some other sources may come in much more powerfully, and the gain will need to be turned down.
The goal is for the incoming audio sources to be relatively equal in intensity, so there isn’t a noticeable difference in sound intensity when switching between them.
While some mixers have 2 or 4 EQ knobs, it is most common for them to have 3 EQ knobs, which control treble (hi), midrange (mid), and bass (low). These knobs adjust the levels of the corresponding frequency ranges. These can be adjusted for smoother mixing.
Channel Level Meter
The channel level meter is a visual representation of the signal’s volume after the gain and EQ adjustments. This offers a way to match the levels of the next track to the one that is currently playing. You can’t tell how loud the new track will be in your headphones because that has a separate volume knob, but you can match the levels visually.
The meter has several green lights, a couple of yellow lights, and then a couple of red lights. The red lights indicate that the signal is so high that the track will “clip,” meaning that it will play so loudly that it will distort the audio quality. You want to make sure the meter shows as much green without showing too much yellow or any red and matches what is currently playing.
The channel up fader allows you to control how much of the audio signal from the output (after modified by the gain and the EQ knobs) will be allowed into the main mix. It works like a faucet that can be fully closed and allow no sound through, fully open, allowing all of the sounds through, or some gradient of partially open.
The above mixer features appear in duplicate, allowing you to adjust the audio of each input separately individually. After passing through the channel up faders, the individual channels are combined into one signal that will be adjusted and sent through the outputs to the speakers or other destinations.
Rec Out Output
If you are recording the session, the signal will now go out the Rec Out output to the recording device. This output’s level usually cannot be adjusted any further at this point.
Booth Out Output
If you are performing for a large crowd, you may need your own set of speakers to monitor the sound levels. Because the loudspeakers are pointed away from you, toward the crowd, the sound you hear from them would be a distorted version that is reflected back to you.
Booth (or monitor) speakers are smaller speakers pointed toward you so that you can hear an accurate version of the mix that is being played over the loudspeakers.
Booth (or Monitor) Knob
Because you don’t need the booth speakers to be as loud as the ones playing for the crowd, they are controlled by this separate volume control.
Master Out Output
The master output the signal to the loudspeakers that the crowd will be dancing to. It is the final mix of the various audio inputs that you have adjusted using the gain and EQ knobs, as well as the crossfader, which determines how much of each signal is played.
The master output sends the audio signal to the amplifier, which will be discussed below.
The master knob allows you to control the signal of the master out output, which is what is sent to the speakers.
Master Volume Meter
The master volume meter is a visual representation of the signal going to the speakers. Again, the meter has several green lights, a couple of yellow lights, and then a couple of red lights. The red lights indicate that the signal is so high that the track will “clip,” meaning that it will play so loudly that it will distort the audio quality. You want to make sure the meter shows as much green without showing too much yellow or any red.
The crossfader is the only fader on the DJ mixer that runs horizontally instead of vertically. The crossfader allows you to control how much of each channel is sent through the master output.
Another important feature of a DJ mixer is the ability to preview the audio inputs by listening to them via headphones that receive a different output than the master, booth, and recording outputs. This output is marked as a cue and has its own selection buttons, level meter, and fader.
What is an Amplifier?
The audio signal that is sent out of the DJ mixer’s master out output is a relatively weak signal, typically about one tenth of a watt. If this were sent directly to the speakers, it would be very quiet. Instead, the signal is sent to an amplifier.
An amplifier’s only job is to amplify this signal from one tenth of a watt to whatever wattage is required by the different size speakers you may need – usually ranging from 500 to several thousand watts.
Typically one amplifier is used to power two passive speakers. In the case of powered speakers, the amplifier is built into the speakers themselves, allowing them to be connected in a series. Powered speakers are much easier to setup due to the amp being built in and I’d highly recommend using these instead. Space is saved and less wires are appearing in your studio.
While there are many different configurations of equipment that will produce the sound you need to make the crowd dance, only running the signal through a DJ mixer directly to passive speakers will not work because a DJ mixer is not an amplifier.
I’ve written some articles and advice on mixers that might help you getting to know your way around mixers and which ones to buy.
- 11 Tips For Using EQ Effectively on a DJ Mixer
- DJ Controller vs DJ Mixer: What’s the Difference?
- What is Clipping in DJing? Stop Redlining Your Mixer
- My Recommended DJ Mixers here
Do you need an amplifier for DJ speakers?
Amplifiers are only required for certain types of speakers. Passive speakers require connection to an amp for sound to arrive to passive speakers. Powered speakers contain amplifiers within them so do not require a separate amplifier. Simply plug in and switch powered speakers on to then connect them to a DJ mixer.
What does a mixer do for a DJ?
A mixer manages multiple signal arriving to the 2 or 4 channels. Various controls allow DJs to manipulate signals to smoothly transition between audio track to track, creating a continuous mix of music.