If you’ve ever had the awesome experience of tracking a band in a professional recording studio, you’ve undoubtedly had the pleasure of gazing upon a massive array of cables of all kinds and wondering whether you would have to purchase as many to achieve a similarly capable setup at your home studio.
Though, for today’s modern audio engineer, buying the right cable need not be a complicated affair, as most audio interfaces are compatible with a select number of industry standard cable types that are relatively inexpensive.
We’ll explore the different kinds of audio cables that exist today, how they’re used in different applications, and which ones you should purchase for your setup.
Perhaps the most common cable type in the professional audio industry, XLR cables are a definitive standard because the inherent design is what allows for a balanced audio signal.
This means that any interference that could be transferred from another electronic device is blocked due to the way that the XLR shielding is built. In any XLR “male” ending, you’ll find three pins:
– Pin 1, which is the “earth” or “ground” cable, represents the first line of defense in preventing interference by making contact first before the two other pins.
– Pin 2 is known as the “hot” pin and is used to transmit a positive polarity of the signal.
– In further reducing interference, Pin 3 is known as the “cold” pin and transmits a negative polarity of the same signal. This inverse polarity between the hot and cold pins ensures robust protection against interference.
2. ¼” (quarter-inch) cable
Also commonly referred to as the TRS cable (TRS stands for tip-ring-sleeve, which I’ll explain in a moment), this features the same fundamental design of the XLR in that there’s a shield that makes initial contact and two wires that run an inversely polarized signal in order to eliminate interference.
Of course, on a mono cable, you will only find a tip and a sleeve while a stereo cable features the ring. There’s an excellent description of how the tip-ring-sleeve configuration works on the Media College website, which states the following:
On the mono plug the tip is the +ve, and the sleeve is the -ve or shield.
On a stereo plug being used for a balanced signal, the tip is the +ve, the ring is the -ve, and the sleeve is the shield.
On a stereo plug used for a stereo signal (left and right), the tip is the left, the ring is the right, and the sleeve is the shield.
3. ADAT Lightpipe
Originally developed by Alesis as an industry standard for transmitting digital audio signals, the ADAT Lightpipe standard allows for up to 8 discrete channels of 24-bit, 48k audio to be transmitted between ADAT-compatible devices.
Of course, if users want to use higher sample rates, then they will have to use less channels to process the incoming signals. This is accomplished by “bit-splitting” via the S/MUX modification, which was developed alongside Sonorus.
It works by trading channels for higher samples. For example, if the user wants to increase the sample rate to 96 kHz, then the amount of channels available will be four as opposed to eight using the 48k sample rate, and if said user wants to set the sample rate to 192 kHz, then the respective amount of channels will be reduced to two for that setting.
Other formats employing similar methods include MADI, S/PDIF, AE3, and other various formats that are frequently employed in professional audio applications and projects. For more exact specifications and information on digital audio formats, I highly recommend you read the “Digital Interfacing” article on Sound On Sound.
Purchasing Cables and Audio Signal Types
If you’re looking to record acoustic instruments using microphones, then you will need to purchase XLR cables, and if you want to record devices such as synthesizers, samplers, drum machines, etc., then you will use ¼” TRS cables to connect them to your multitrack interface. If they have XLR outputs, you can use a DI (direct input) interface to convert the signal to line level so that it can be routed through your interface.
Generally speaking, there are two types of audio signals in the professional audio industry:
- mic level
- line level
The line level reference is measured at +4 dB, while the mic level reference is usually far lower than that. In order to be brought up to line level, microphone preamps are used to convert mic level signals to line level audio. Hardware processors, such as compressors, EQ’s, reverb units, and other similar devices process line level audio and require TRS cables. Oftentime, Y-shaped TRS cables are used to integrate such devices into many audio setups.
The Bottom Line
Most of the time, you will be using either XLR cables or ¼” TRS cables during most of your recording and mixing sessions, and while they are several brands that claim to appear to be “superior” to your average cable, all you really have to know is whether a cable is balanced or unbalanced, which you can easily verify by speaking with a sales associate or doing some research about the cable’s given specifications.