Although Bluetooth has become a common technology for audio devices and is sufficient for our daily use, it is not the best choice for certain specific scenarios or situations that require higher sound quality, and there may be delays.

Especially when you want to enjoy high-quality audio and an excellent sound system experience at home, you may need to use different types of audio cables.

These audio devices often have different interface/plug specifications, and some speakers even offer multiple interfaces.

So what are the differences between these various interfaces? Which interface or connection cable should we use?

Today's article will help you understand it all at once!

Analog Audio vs Digital Audio

There are two common forms of audio transmission: analog audio and digital audio. Let's first briefly explain the differences between the two for better understanding.

1

Analog Audio

Analog cables use continuous electrical signals to transmit information from point A to point B.

The audio quality of analog signals may be affected by signal interference, but most equipment in music studios can use analog cables.

Analog cables can also be divided into balanced audio and unbalanced audio.

2

Digital Audio

Digital cables work by using binary digital sequences (1s and 0s) to transmit data from point A to point B.

Typical interface types include MIDI, S/PDIF, and USB.

*MIDI does not actually transmit audio signals.

Balanced vs Unbalanced Signals

Before understanding the types of audio interfaces, you also need to understand 'balance'.

Balance affects the audio you hear.

Analog cables can be divided into unbalanced and balanced cables. The main difference between balanced and unbalanced cables is their ability to eliminate noise.

The structure of unbalanced and balanced cables is different. The former has one positive wire and one ground wire, while the latter has positive and negative wires along with a ground wire.

The noise resistance capability of balanced cables lies in a pair of polarity wires, where the positive and negative conductors work together to reduce noise and eliminate external electrical interference.

If you want to have the most balanced and professional audio setup, you should not only use balanced audio cables but also balanced equipment.

Types of Analog Audio Cables/Interfaces

TRS

TRS cables are easily recognizable and are common in our daily lives.

A TRS connection consists of three parts separated by two black stripes: Tip, Ring, and Sleeve.

TRS cables are mostly balanced; they can be used for both balanced mono signals and unbalanced stereo signals.

TRS connection cables come in various sizes, including 1/4 inch (6.5 mm), standard 1/8 inch (3.5 mm), and 1/16 inch (2.5 mm). They can be used for stereo audio connections such as headphones, microphones, and instruments, as well as professional audio equipment including audio mixers and interfaces.

The output of the M-Track Duo sound card is a standard TRS specification, with left and right channels transmitting balanced signals separately.

The balanced signal from the sound card needs to be transmitted to the speaker; once we clarify the input interface type of the speaker, we naturally know which cable to use.

For example, M-Audio's BX5 D3 monitor speakers provide TRS and XLR input interfaces on the back panel. This means you can directly use a TRS connection cable to connect the M-Track Duo sound card to the BX5 D3 speakers.

2

TS

TS (Tip-Sleeve) cables look very similar to TRS cables but are easy to distinguish because TS connection cables only have one black ring.

TS cables are always unbalanced; they are used for mono audio devices. They can connect to instruments such as guitars, keyboards, and other audio devices with unbalanced outputs.

Therefore, TS cables can also be referred to as instrument cables. These cables can also be extended, making them ideal for stage performances. TS cables mostly come in standard sizes of 1/4 inch (6.5 mm).

Monophonic analog synthesizers like Sequential Prophet-5 Rev 4 and Moog Model D typically use TS output types; when connecting, they need to output to corresponding interfaces such as instrument inputs on sound cards or mixers, or TS unbalanced input interfaces on speakers.

Some speakers also use a 3.5mm TS connection cable for main/sub connections, such as M-Audio's popular multimedia Bluetooth monitor speakers BX 3 BT and BX 4 BT.

[BX4 BT uses a 3.5mm TS type main/sub connection]

The connection methods for BX3/4 BT are very rich; it also comes with various types of connection cables. Some friends may not know how to connect after opening the package, especially with two 3.5mm connection cables that can easily be confused:

We just need to observe the plugs of the connection cables; one with a ring is for main/sub connections between two speakers; two rings are used to connect to the AUX input on the front panel of the main speaker, while another end can connect to devices like phones, tablets, or music players.

3

RCA

RCA cables are a type of analog audio and video cable.

RCA stands for Radio Corporation of America, which introduced this connection in the 1930s.

Like TS cables, RCA cables only have two wires and are unbalanced; therefore, it is best to use them over short distances to avoid signal degradation.

RCA is usually color-coded. The yellow RCA connector is typically used for composite video signals; white/black connectors are used for the left channel of stereo audio, while red connectors are used for the right channel.

RCA cables are unbalanced cables commonly used for audio and video components, such as DVD players, game consoles, or other display devices. You can often find them in home A/V systems.

In addition, RCA cables are also used in DJ equipment and some professional audio and video devices.

You can connect most devices using a pair of RCA to RCA cables, but if your devices are incompatible, you can also convert the RCA interface to other types of interfaces, such as 3.5mm to RCA cables.

iLoud Micro Monitor (MM) speakers offer RCA and 3.5mm TRS input types.

Like the BX 3/4 BT, it comes with a 3.5mm to RCA connection cable:

4

XLR

XLR cables, also known as microphone cables, originated from the Cannon X series connectors invented by James H. Cannon.

These cables are considered some of the most durable and standard audio cables and are very common in the audio industry.

XLR connectors can have 7 or more pins, but the 3-pin XLR connector is the most common in everyday life.

The locking design makes XLR cables a popular choice because it prevents accidental disconnection during use, making them ideal for live performances on stage.

XLR has female and male connectors. The former is typically used for outputs from microphones, instruments, or other audio devices; while the latter is used for inputs on mixers to receive signals.

XLR cables are always balanced, meaning they can be long without suffering from any signal interference, making XLR cables suitable for live performances and professional recording studios.

In general, XLR cables are compatible with many new and old devices, including microphones, PA systems, and specific instruments.

The inputs of sound cards often use composite input interfaces that allow you to connect microphones using XLR or TRS and instruments using TS.

This is also common on the input interfaces of some speakers:

[iLoud MTM MK II (second generation) monitor speakers]

Digital audio cable/interface types

1

MIDI

MIDI is the English abbreviation for Musical Instrument Digital Interface and typically uses a five-pin design.

Although it does not transmit audio signals, MIDI cables are still considered a type of audio cable and play an important role in synthesizers, instruments, and other electronic devices.

For example, it is commonly used to transmit musical data from keyboards, synthesizers, drum machines, and computers.

MIDI interfaces are also common on many sound cards:

The above image shows the M-Audio Air 192|8 professional recording sound card, which has MIDI input/output interfaces in a 3.5mm specification.

2

USB

USB (Universal Serial Bus) has become one of the most common data transfer industry standards.

It can certainly also transmit digital audio data and is the world's most well-known digital audio cable widely used for transferring digital audio data between computers and other devices such as audio interfaces and MIDI keyboards.

Most sound cards we currently use connect to computers via USB transmission.

3

S/PDIF

S/PDIF cables, or Sony/Philips Digital Interface cables, come in both optical and coaxial forms.

The optical form uses fiber optic cables with TOSLINK or mini-TOSLINK connectors, while the coaxial form uses coaxial cables with RCA connectors.

S/PDIF cables are gradually being replaced by HDMI cables but are still used in home theater systems, game consoles, set-top boxes, or other entertainment devices.

Monitors equipped with S/PDIF digital audio interfaces

From Monkey Banana's Turbo 6

Three things to consider when choosing audio cables

1

Length

Audio cable lengths vary from a few inches to several feet. The length of the cable does indeed matter for sound quality, especially when purchasing unbalanced audio cables. It is well known that longer audio cables can lead to signal degradation and affect sound quality.

Of course, different occasions require different lengths of audio cables. For example, live performances require longer audio cables to connect instruments to mixing consoles or amplification systems. But studios are better suited for shorter audio cables to avoid noise.

2

Audio signal levels (strength)

Before choosing an audio cable, you need to understand the following four types of audio level standards.

- Microphone Level (Mic Level): This is the weakest level of audio signal.

When recording, it usually requires a preamplifier to boost it to standard line level; otherwise, the microphone's signal will be too weak.

When using dynamic microphones with very low sensitivity like the SM7B, you can also pair it with a Cloud mic preamp to amplify the microphone level signal.

- Instrument Level: This is a stronger signal level than microphone level and is typically used for instruments like guitars, basses, keyboards, and synthesizers. Instrument level signals can be matched to line level equipment using DI boxes.

- Line Level: This is considered the standard audio signal level used by most audio equipment.

- Speaker Level: This is the strongest level of audio signal that can produce sound waves audible to people.