Let’s be honest, trying understand all of the different types of audio cables and which ones you need is pretty tedious to begin with. However, once you have the know-how, you can simply just get on with having fun and creating, whether that be for podcasting, recording music, or streaming. I’ve put this complete comprehensive guide together to help you understand all of the different audio cable connector types, how they work, the differences, and their purposes.
After reading this article you should have all the knowledge you need to get started without any hesitation or confusion. To keep things simple, I’ve only included the most common types of audio cables you will need to start home recording successfully. If I were to write a guide for all possible audio cables, like those used for live sound and high-end professional recording studios, then this would be a massive list. Firstly, there are two types of cables you need to be aware of.
Analog vs Digital Cables
Understanding the difference between analog and digital is one of the first things you need to be understand. But what is the difference between analog and digital cables? Analog cables, such as what you use for a guitar, transmit information through electricity. Digital cables, such as a USB one, transmit information through binary code, meaning a series of 1’s and 0’s. Straightforward enough, right? Great. Let’s look at signal levels now.
When working with audio equipment it’s important to understand and be mindful of the different signal levels. Some have a higher output than others and if you’re not careful you could do some damage.
Mic level (balanced) is for microphones via XLR cables and is the lowest level. In order power microphones correctly you need a preamp to boost them up to line level. For home recording most people buy an audio interface which has inbuilt preamps. You can read all about audio interfaces in my article ‘What is an Audio Interface?’.
Instrument level (unbalanced) is a variable level which uses TS cables, like the ones for a guitar or bass. Instrument level also requires a preamp for it to be boosted to line level.
Line Level (balanced) is the highest signal level and is the standard strength for a large range of audio equipment. We use it for anything that is not an instrument or microphone. This could be studio monitors, headphones, outboard gear or sound processors such as a synthesiser, keyboard, drum machine, compressor, effects unit and so on. For line level we use TRS cables, or TS cables for unbalanced audio equipment.
Balanced vs Unbalanced Cables
What even is the difference between balanced and unbalanced cables? Every beginner asks this, just as did I when I started. Let’s started with balanced cables.
The big advantage of balanced cables is that they are much better at cancelling out noise and are more immune from audio interference such as that from a radio. For this reason, they are the industry standard for professional audio equipment.
How do they achieve this? It’s all down to their intuitive design. Balanced cables have three wires:
- Signal +
- Signal –
When audio runs through a balanced cable, the + signal and – signal run through simultaneously, however the – signal is inverted making it out of phase with the positive signal. Both wires carry noise but before reaching their destination, the inverted signal is flipped back to match the positive signal, which causes the noise to be cancelled out. Sound confusing? Don’t worry, it is. All you need to know is that it’s a very clever design that works superbly to reduce noise.
Unbalanced cables are more susceptible to noise as they only have two wires, a signal and a ground. So, why are do we use them? Due to the design of instruments like electric guitars, they can’t begin with a balanced cable. However, they can be converted with the aid of something like a DI box. This would be necessary if the guitar player was using a very long cable (20-20 ft) which are prone to noise.
Now you know about basic cable technicalities, let’s move on to the most common types of cables for home recording, starting with analog cables.
XLR cables are balanced and we use them for microphones. They have a male side with three pins and a female side with three holes. These three points of contact are what help them to reduce noise, as I showed you earlier. XLR cables come in a wide range of lengths but as they are balanced, noise shouldn’t be an issue.
1/4-inch – The Holy Grail of Audio Cables
1/4-inch (6.35mm) cables are the most common due to their versatility. There are two main types that you need to be familiar with and it’s easy to get confused between the two.
The TS Cable
TS cables can only send a mono signal, which means it can only send one signal at a time. The opposite would be stereo that allows you to send two signals, for example left and right. TS cables only have two points of contact which are the tip (positive) and sleeve (ground). Remember what that means? That’s right, they are unbalanced. TS cables are used for guitars, basses, keyboards, synthesisers and so on.
TRS cables have three points of contact which means they are balanced. TRS cables can send a mono signal or stereo signals, the tip carries the left-channel and the ring carries the right-channel. They are used for professional audio equipment such as studio monitors which require stereo, or to connect a mono synthesiser with a balanced input to an audio interface with balanced TRS inputs.
RCA Cables are unbalanced and carry stereo signals. The red cable carries the right-channel and the white cable carries the left-channel. You often use RCA cables to connect home stereos and hi-fi systems, however they are much less common nowadays than they used to be.
Digital cables are always advancing and changing. Which to be honest is a pain as you have to stay up-to-date with them. Unless you’re planning to build a professional expensive recording studio -unlikely if you’re a beginner- then the ones below are all you need to know about at the moment. If you are curious about other types you have come across though, please feel free to comment and ask me a question.
I’m certain you’re familiar with these types of cables already, but if not let’s talk about them. USB stands for Universal Stereo Bus and we use them for a large range of electronic items. With regards to audio equipment specifically, USB microphones, audio interfaces, MIDI keyboards, and digital pianos/keyboards all use USB. It’s common to see USB A to USB B cables for such devices (as pictured above). USB speeds are always increasing, and as it stands the fastest available right now is USB 3.0, which is ten times faster than USB 2.0.
What a name! One that suggests speed and power. Thunderbolt has unprecedented speeds and is used for higher-end audio interfaces such as the Universal Audio Apollo Twin. For most home recording purposes you certainly don’t need an audio interface with a Thunderbolt connection. It’s more of a necessity for professional, or semi-professional engineers who need a lot of speed for conducting large recording sessions.
MIDI stands for Musical Instrument Digital Interface. These cables have 5 pins and we use them to connect for MIDI compatible audio gear, or MIDI controllers such as a MIDI keyboard, although most MIDI keyboards use USB these days. MIDI is an exceptionally powerful tool in music production and has been for a very long time. If you want to read more about that, check out my article ‘What is a MIDI Keyboard?’.
Pronounced like spuh-dif, now try saying that ten times fast. SDIF cables allow us to connect external hardware such as DVD/CD players, game consoles, effect unites such reverb, delay, and some synthesisers. SPDIF can send or receive two channels of audio, meaning it’s more limited than optical, which I’ll talk about next.
Optical / ADAT
Optical also known as ADAT can send or receive 8 channels of audio. Optical can be used for a range of purposes such as connecting a mixer, PA, or even another audio interface to your existing one to expand the amount of inputs and outputs you have.
Both SPDIF and Optical inputs/outputs are found on more expensive audio interfaces as they give you more connectivity options. So, they’re great if you want to connect more gear to your existing recording setup, allowing you to expand your studio.
An Audio Interface in Action
So, now you have a list of cables and their purposes, but I want to demonstrate how you would use these cables for a typical home studio setup, using an audio interface. A lot of audio interfaces these days -like the one in this diagram- have combo inputs on the front, meaning they can take either an XLR cable, or a 1/4-inch cable. These types of combo inputs also accept instruments at instrument level and devices at line level. You can change the signal level by the pressing the instrument button on the front, which sets the impedance to instrument level. When it’s off, the audio interface is ready for line level.
Firstly, on the front of the audio interface you can see a microphone (line level) is plugged into the combo input via an XLR cable. Next you can see the appropriate hole size on the combo input to accept a1/4-inch cable, for either an instrument like a guitar (instrument level) with a TS cable, or a device like synthesiser with a TRS cable at line level. Simple enough? Cool. Finally, you have an output for your headphones (line level) which use a TRS cable.
Moving on to the back. First, you can see the MIDI input and output, which you guessed it, use MIDI cables. Remember MIDI cables are digital, so they don’t have a signal level. Next you have line outputs (line level), which you could use for studio monitors, or to send audio from the audio interface to a sound processor. Finally, there are some dedicated line inputs (line level) to send audio into the audio interface from a device like synthesiser, drum machine, electric piano etc. And there you have it. Once you see the most common inputs and outputs on audio interface, with the cable types, it’s not so intimidating.
Understanding Audio Cable Connector Types is Essential
Understanding the different audio connector types and their purposes is essential before you start your own home recording studio. It doesn’t matter if you want to record and produce music, create a podcast, or live stream, you need to understand the equipment you’re going to use. I really hope that this guide has helped you out along your path. Do you have any questions? Please feel free to comment down below, I’m more than happy to help you.