Cables! They plug your stuff together. What’s more to know? Right? As unsexy and unfulfilling as cables are, they are probably the most common piece of equipment type in your studio.
There are all kind of different cables. You’ve got power cables, mic cables, speaker cables and instrument cables. Lightpipe and digital coaxial cables. And once you realize the volume and scope of what cables do in your everyday workflow, you suddenly realize the grand importance of cables in your studio!
But they’re still pretty boring.
However, given some basic tips, you (like I) can think about your cables as little as necessary while still giving them the respect they deserve. I’ll be focusing on cables commonly used in podcasting setups, with particular attention to microphone and monitor cables.
When it comes to untangling them, you’re on you own. But here are a few helpful hints to help you on your way to properly forgetting about cables, so I can forget about them, too.
There are three very important things to understand about power cables in the studio:
- Don’t cross the streams.
That is, don’t let electrical cables cross your audio cables. Electrical cables can produce electromagnetic interference that when crossing an audio cable produce a low pitched tone or buss. This is the dreaded 60Hz hum (50Hz in Europe).
- All AC power cables should be grounded.
Most of your equipment will already be properly grounded. It’s important to maintain proper grounding by not using adapters to adapt to improper and ungrounded extension cords. Improper grounding produces unwanted noise in the system and our main objective in any studio is to produce clean audio with as little unwanted noise as possible.
- Ground to the same ground.
Ground loops can be nasty, both to your audio signal and in terms of finding the source of the unwanted sound assassin. In general, a ground loop is typically caused by plugging one piece of grounded audio equipment into a power strip powered by one AC outlet, plugging another into a powerstrip powered by another outlet and then plugging the two pieces of equipment together via an audio cable. The ground signal (that 60Hz/50hz hum!) travels along the shield in the cable and causes a ground loop. To avoid this, ensure all equipment is plugged into power strips on the same outlet.
A word about USB
I want to talk briefly about USB. I often get questions about USB microphones and USB audio monitors (AKA speakers) versus XLR or other options. Quite simply, the decision between USB and analog connections is largely up to you, your team or the producers and engineers you work with. In general, you’ll want to consider your budget, scope and workflow to determine what works best for you.
In my studio, analog microphones are a must. I use microphones in the field and on the go in a number of different environments and scenarios. I use them to microphone fruit. I purposefully drop them in water. In the studio, I am apt to record many voice talents at once through a single device.
If you need your arrangement to be flexible and mobile, require long cable runs, or require multiple microphones, instruments or other audio equipment recording simultaneously, you’re likely going to want to look at analog solutions.
If you’re a one-voice, one mic operation (a voice actor or single podcast host, for example), a USB solution may suit your needs and workflow well. In that case, my Beginner’s Guide to Microphones will get you on your way.
If you’re a one-person-one-recorder on-the-go operation, a USB microphone and a USB to micro USB adapter can often be used in conjunction with your smart phone and produce excellent results.
So which is better? It's layered, and arguable. Pound-for-pound, a Samson C01 and the C01U perform equally well. However, a cheap consumer USB microphone can be the audio equivalent to a Barbie microphone. USB microphones also have a built in microphone preamp (mic pre) that will affect the sound differently than the preamps in your recording setup. Overall, however, there isn’t much of a noticeable difference between USB and XLR versions of the same microphone.
For performance, flexibility and adaptability, nothing beats an XLR microphone. If you’re going to be working with others or alternating between live a studio situations, XLRs are standard. Most professional equipment is fitted with XLR inputs and XLR is easily used in TS and TRS jacks using a simple adapter.
That said, a good XLR-to-USB adapter can make an already flexible rig even more flexible. If you’re in the market for an XLR-to-USB adapter, I recommend one that has a headphone jack for monitoring and phantom power for use with a larger variety of microphones.
Jack vs. Plug
The most basic terms to understand when it comes to audio cables refer to the cable and equipment connectors and how they connect. Those are Jack and Plug. Plug refers to the end of the cable that inserts into your equipment, typically a male end of an RCA or Phone jack. The simplest way to remember this is that a plug is inserted into a jack. Plugs tend to be male. Jacks tend to be female.
The principles of operation are fairly simple. The electrical signal from the audio source travels along a conductor inside the cable and returns along a second conduit or shield. Think of like in a basic electrical circuit because it is a basic electrical circuit.
Balanced vs. Unbalanced
The primary difference between balanced and unbalanced cables is that balanced cables return the electrical signal along a secondary connector instead of carrying it along the cable shield where ground noise and electromagnetic interference can cause hum in the signal. The process works similar to a ground in an electrical outlet, isolating the audio signal from electromagnetic interference and ground current. In general, it is always advisable to use balanced cables. However, heavy gauge unbalanced cables less than ten feet long will provide adequate hum rejection, if necessary.
So, why do unbalanced cables exist at all? A few reasons. In the studio, unbalanced cables are used as instrument cables to plug guitars, basses and keyboards into amplifiers. Instrument cables also cost less, and provide adequate hum rejection for most home recording and home stereo situations. It is also far simpler to run unbalanced cable for vehicle and household audio needs, as an added conductor increase cable width. In short, they are primarily for consumer use, or for other applications where professional sound quality isn’t a factor.
Gauge refers to the thickness of the wire used in a cable. Gauge affects sound through impedance (or resistance). Think of it like a PVC pipe. The wider the PVC pipe, the more water can travel through the pipe at once. The same is true of electricity and wire gauge: the thicker the copper, the more audio signal can travel through at once.
The most confusing thing about gauge is how the numbering works. Counterintuitively, a smaller gauge refers to a thicker wire and therefore less impedance. In general, heavy gauge wire between 12 and 16 gauge is suitable for most audio cables (remembering the 12-gauge is thicker than 16-gauge).
In most applications, gauge is not something you’ll have to think about often, but it comes up from time to time in cheaper-made cables, especially unbalanced.
Types of Analog Audio Cables
For the most part, analog audio cables break down into four different types: XLR, phone cables, RCA and speaker wire.
Speaker wire, in general, is used for consumer audio and live audio applications (though I have certainly been known to use it in my studio from time to time). In general Speaker wire is unbalanced and should be avoided.
RCA cable is used in studio applications to connect CD, tape and record equipment and various consumer-grade equipment into mixing boards and recording devices. RCA is also used for S/PDIF (Sony/Philips Digital Interface Format) digital audio interfaces. When used as an analog source, however, they are unbalanced and should be avoided whenever possible. In a pinch, a USB-based solution will likely provide better sound quality than its RCA equivalent without potential for line noise or hum.
Phone cable is by far the most common cable in both studio and consumer audio applications. In professional applications, phone cables are designated by the configuration of the metal conductors on the plug:
- TS (Tip-Sleeve) or various “mono” plugs
TS cables are single conductor, unbalanced cables.
Applications: Patch cords, instrument cables, unbalanced microphones.
- TRS (Tip-Ring-Sleeve) or various “stereo” plugs
TRS cables are dual conductor, unbalanced cables.
Applications: Balanced microphone input, balanced monitor cables, unbalanced stereo input, stereo headphones.
- TRRS (Tip-Ring-Ring-Sleeve)
TRRS cables are three conductor wires, unbalanced cables.
Applications: Typically used for microphone/headphone inputs for cell phones, tablets and other small electronics.
XLR is a 3-pin professional audio standard connection type for balanced microphones and balanced recording equipment. If you are looking for cables for microphones and are not using a USB microphone, XLR is pretty much the standard in microphone applications as well as professional audio equipment for use in live and studio sound. It consists of a pin 1 ground connected to the cables shield and two conductors carrying the balanced audio signal.
So, there you have it. Cables! To wrap up, here's our advice:
- favor balanced cables like XLR and TRS cables in your audio setups.
- If unbalanced cables must be used, keep them under ten feet and 12 to 16 gauge to reduce the chance of hum and other interference.