With so much attention these days focused on the latest and greatest gear…
Like for instance…
It’s easy to neglect some of the less-glamorous aspects of the studio…
Like cables, for instance.
Because once it’s all connected, and working as it should…
You forget they even exist. And that’s how it should be.
Getting to that point requires A LOT more knowledge than some might imagine.
Which is why, in today’s post entitled: The Ultimate Guide to Audio Cables for Home Recording…
I’ve compiled an in-depth look at all the must-know facts of this important subject.
If you don’t know your cables yet, by the end of this post you will.
Analog vs Digital Signals
The first question every beginner asks is:
What’s the difference between analog and digital cables?
- Analog cables work by transmitting information through stream of electricity, and…
- Digital cables work by transmitting information through a long string of 1’s and 0’s (aka binary code).
For a detailed explanation on digital audio, check out this post. For now though, let’s focus on analog.
The Basics of Analog Cables
In the recording studio, there are 2 types of analog cables:
…that we use to transfer 3 levels of audio signal:
- Mic Level – (balanced)
- Instrument Level – (UNbalanced)
- Line Level – (balanced)
Line level is the standard signal strength used with all pro audio equipment. Which is why mic/instrument level signals are first boosted to line level before entering the signal chain.
Instrument level signals, which come from electric guitar/bass, are sent through a standard guitar cable, which is then boosted to line level using a direct box.
Mic level signals, which come from your mics, are sent though a standard microphone cable, which is then boosted to line level using a mic preamp.
For more info on microphone cables in general, check out this post:
Balanced vs. Unbalanced Cables
The next most common question beginners ask is:
What’s the difference between balanced and unbalanced cables?
In terms of performance:
Balanced cables are relatively immune to noise from interference such as radio frequencies, electronic equipment, etc. Which is why they’re the standard for pro audio.
In terms of design:
BALANCED cables have 3 wires:
- Signal (+)
- Signal (-)
While UNBALANCED cables have only 2:
The addition of the 3rd wire in a balanced cable is exactly what makes noise-cancellation possible. Later in this post, I’ll explain how it works. For now though, let’s continue with the basics.
Analog Connectors Explained
On either end of a balanced analog cable, you will find 1 of 3 connectors:
- XLR Male – which connects to various hardware inputs.
- XLR Female – which connects to the microphone, and various hardware outputs.
- TRS – which connects to both inputs AND outputs.
Each of these connectors has 3 contact points which carry signals from the positive, negative, and ground wires previously mentioned.
- XLR male has 3 pins
- XLR female has 3 holes
- TRS has 3 surfaces known as Tip, Ring, and Sleeve
Unbalanced analog cables typically only use one connector, which is the TS connectors commonly seen on instrument/guitar cables.
TRS vs TS Connectors
The third common question folks ask is:
What’s the difference between TRS and TS connectors?
As you can see in the picture, TRS connectors have 3 contact points, while TS connectors have only 2.
The extra 3rd contact point on a TRS connector is what allows it to carry a balanced signal.
The balanced wiring for TRS goes:
- Tip = Positive
- Ring = Negative
- Sleeve = Ground
While the unbalanced wiring for TS goes:
- Tip = Positive
- Sleeve = Ground
How Balanced Cables Cancel Noise
Earlier I promised show you exactly how this works.
So here’s the explanation:
When audio enters a balanced cable…
Both the (+) and (-) wires receive identical versions of the signal…
The only difference is, polarity of the (-) wire is INVERTED.
As the two signals travel along the cable, BOTH wires gather noise, the same way unbalanced cables do, however…
Before re-combining them at the opposite end of the cable, the polarity of the negative wire is flipped BACK, to once again match the positive signal.
With the noise patterns now on OPPOSITE polarities, they cancel each other out, leaving the original signal noise-free.
Converting Signals from Unbalanced to Balanced
By now, you’re probably wondering:
If unbalanced cables are noisier, why use them at all?
Well the answer is…
Due to the design of electric guitars and other instruments, it’s not always possible to start off with a balanced signal.
But what you CAN do is convert them, as necessary. For example, because guitar cables get too noisy beyond 20-25 ft…
A direct box (aka DI, aka direct injection) is commonly used to change the unbalanced guitar signal into a balanced mic signal…
Which can then be extended for several-hundred-feet, through a standard XLR mic cable.
Balanced MONO vs Unbalanced STEREO
People often get confused, the first time they notice…
That the TRS connectors used on balanced cables…
Are the same connectors as those found on their headphones.
And they wonder:
How can that be, when one is mono, and the other is stereo?
The answer is: STEREO headphone cables are UNblanced.
So unlike balanced MONO wiring, which has a (+), (-), and ground…
Stereo headphone wiring looks like this:
- Tip = Left Channel
- Ring = Right Channel
- Sleeve = Ground
Got it? Awesome.
Now that we’ve got analog cables covered, let’s move on to the second half of this post…
Where we talk about…
The good news about digital cables is, unlike analog cables, you don’t really need to understand much about how they work, in order to use them.
The bad news is, there’s A LOT more of them, and the current ones are constantly being replaced as newer technologies develop.
As of 2018 though, here are the ones you should know:
1. The Three Interface Cables
The one digital cable that every studio MUST have is…
The one that connects your audio interface to your computer.
And undoubtedly, it’s one of these 3:
- USB – the standard for budget interfaces, it has the slowest data transfer of the 3, but still works well enough for home studios.
- Firewire – typically seen on pricier interfaces, it offers significantly faster speeds than USB.
- Thunderbolt – only seen on newer high-end interfaces, it offers unprecedented data transfer rates, previously only seen on dedicated PCIe processing cards.
Soon we may also see interfaces with USB 3.0, which rivals the performance of current thunderbolts.
2. MIDI Cables
Commonly used by electronic musicians…
MIDI cables transfer data between various electronic instruments and related digital devices…
Using a language known as MIDI (Musical Instrument Digital Interface)…
Which communicates various types of musical information, including notes and velocity.
In home studios, these cables usually run from keyboard/MIDI controller to a MIDI interface, which connects to your computer, and lets you control the virtual instruments within your DAW.
These days, MIDI cables aren’t nearly as common, as USB cables have now made it possible to transfer MIDI data directly to the computer.
3. Optical Cables
By transferring information using a series of light flashes…
Optical cables (aka lightpipe cables), can carry multiple channels of digital audio through a single cable.
The 2 signals it accepts are:
- ADAT – which carries 8 channels at 48kHz, or 4 channels at 96kHz
- S/PDIF (aka TOSLINK) – which carries 2 channels of audio
In the studio, ADAT is commonly used to send all 8 channels of a multi-channel mic preamp to the audio interface.
S/PDIF is commonly used to output your stereo mix from the audio interface to an external source such as a cheaper pair of monitor speakers.
4. BNC Cables
Identical to the coaxial cables used to connect your cable TV…
But with a different name and purpose…
BNC cables are used in the studio to sync the internal clocks of multiple digital devices, whenever two or more are connected.
Without them, the digital devices cannot sync properly, resulting in mis-aligned samples, and annoying clicks and pops in the audio.
While simple studios rarely use BNC cables, larger studios with advanced signal routing often require them.
5. AES/EBU Cables
The strangest of all studio cables…
AES/EBU cables use the XLR connectors of an analog mic cable…
To transmit the S/PDIF signal of a digital optical cable.
While not common with budget recording gear, they’re often used on higher-end interfaces and other hardware.
One fact that few people know is…
The term “AES/EBU” is actually an audio signal (NOT cable), that can work with several different connectors including:
It’s only because the XLR versions are most popular, that we associate them with the name.
As you might imagine, they can be easily mistaken for mic cables…so if you use them, be sure to label them.
6. Cat5e Cables
The same cables as those used with home telephones…
Cat5e cables work great in the studio as well…
Because of their ability to send BOTH a power source, and multiple channels of digital audio, through a single line….
As well as…their ability to stretch LONG DISTANCES with extremely LOW LATENCY TIMES.
This combination of features makes them perfectly suited to meet the needs of many high-end headphone distribution systems.
And some of the most advanced systems can send up to 40 channels of audio to a personal mixer, with just a single cat5e cable!
Now that we’ve covered both analog, and digital cables…
All that remains is: power cables.
The great thing about pro audio is, you use the same one for almost everything.
Known as the IEC C13 (or IEC for short), this one cable is used on virtually everything from computers, to studio monitors, to studio rackmount setups.
Over time, studio collect tons of them, so if you ever lose one, chances are good you’ll have a few back-ups.
Now that we’re nearing the end, the final topic I’d like to cover is organization.
It’s not hard to imagine that for most studios, cable organization is a constant struggle.
So to conclude this post, here are 3 tips which help make it easier:
1. Use Snake Cables
If too many cables is your main problem…
A snake cable can offer the perfect solution…
By essentially combining many individual cables into ONE.
For home studios, this has 2 benefits:
First, it allows you to dramatically reduce the clutter behind your rack, so you can actually make changes without untangling a spider-web of cables.
Second, it allows you to relocate the inputs of your mic preamp to literally anywhere in the room…which gives you one less reason to dig behind your rack.
To learn more about snake cables, check out this article:
2. Use Cable Winders
While pro studios might laugh at the idea of using cable winders…
In a typical bedroom studio, where each day you roll up your ONE guitar cable, and ONE mic cable…
Cable winders can make this tedious job a lot less painful.
To extend it, simply pull it out to the exact length needed and it locks itself in place.
To retract it, just firmly tug at the base, and it rolls itself up, automatically.
While some folks call them gimmicky…there are many others (myself included) who absolutely love them.
For home studios, these are the 3 I recommend:
And for the final tip…
3. Solder Your Own Cables
In pro studios, you rarely see exposed cables anywhere. The reason is…
By cutting and soldering their own cables, they can tailor each one to the exact perfect length for the job.
In home studios on the other hand, it’s not uncommon to see a 25 ft cable used on a 3 ft connection.
Think soldering is too hard?
Well I can tell you from experience, it’s not nearly as challenging as many people assume. With a few basic tools and some practice, virtually anyone can do it.
So if you’re interested…
Here’s a good video I found which explains how it’s done:
And here’s a checklist of the essential items covered:
- a pair of pliers with a wire cutter
- a soldering iron
- a roll of solder
- a roll of balanced cable
- XLR male and female connectors
- TRS connectors
It’s not a job I recommend for everyone, but handyman-types can easily learn this technique with just a few hours practice.
And as an awesome side benefit…
All those old cables and connectors you no longer use can be scrapped for parts and re-purposed over-and over again, to follow the ever-changing needs of your studio.