How to set up multiple analog interfaces to a single sound device

Question

Pre note: Complete beginner talking here.

I have been DJ'ing for a while, using a traktor s4 combined with traktor 2 software. Mixing is fun, but I like to do more with music. A while ago I decided that I want to perform live. Today I've taken my first few baby steps into achieving that goal.

I bought myself 3 Korg Volca's (Beats, Keys and Bass).

However, upon arriving home I noticed all 3 volca's have a sync in/out and a single headphone output. My sound system (2.5, 2 speakers and a sub) only has one single (green) input and one double (red/white) input. Leaving me wondering how I am going to link all 3 volca's to my speakers.

After doing some research (note that english isn't my mother tongue, which makes it hard to search for the right terms) I learned that I either need a sound card, an audio interface or an audio mixer.

What are the differences between those, and what can I use so that my 3 volca's can simultaneously play on my speakers? Keep in mind that I hope to expand my 'studio' anytime soon, so the solution should have multiple inputs.

Thanks in advance

Answer 1

• A mixer, also known as sound mixer or [mixing-]console is a device that takes multiple analogue^† signals (often: a lot of microphones plus some line signals, but it can really be anything), and combines them into a single analogue signal. It comes with a couple of dials where you can set how loud each channel is, and at least a simple tone control for each one. This is what you need to perform live with something like those synths.

• An audio interface, aka AD/DA unit, is a device with some analogue inputs and usually also some outputs, which can be connected (via USB or Thunderbolt etc.) to a computer. The computer can then be used to either record/replay sounds, or to process them in real-time. This is what you would need to record stuff you play with the synths, or to add digital sounds. You don't really need it to perform live, but since any interface can also be used as a mixer^‡ this is always an option.

• Sound card is really just another word for interface, but usually means it's encased into one of the computer's PCI slots, rather than external and connected by USB.

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^†_{More and more mixers nowadays are digital, meaning they actually consist of an audio interface and specialised computer in one box.}

^‡_{Note however that most interfaces don't have equalisers etc. built-in, like mixers do. You can still get them if you pass through software on the computer, but this may incur substantial latency.}