Coaxial vs. Optical Digital Audio Cables

Choosing between coaxial and optical digital audio cables sounds like the kind of decision that should require a lab coat, a flashlight, and at least one dramatic graph. In reality, it is much simpler: both cables move digital audio from one device to another, both can sound excellent, and both are still useful even in a world where HDMI walks around acting like it owns the living room.

Still, the difference matters. A coaxial digital audio cable and an optical digital audio cable may carry similar audio formats, but they do it in very different ways. Coaxial uses an electrical signal through a copper conductor. Optical, also called Toslink, uses pulses of light through a fiber-optic cable. One is the sturdy old pickup truck of digital audio. The other is the laser-pointer-wielding librarian: clean, quiet, and allergic to electrical interference.

This guide breaks down coaxial vs. optical digital audio cables in plain English, with enough depth to help you choose the right connection for a TV, soundbar, CD player, DAC, game console, Blu-ray player, or home theater receiver.

What Are Digital Audio Cables?

Digital audio cables send sound as digital information instead of as a constantly changing analog waveform. In home audio, the two classic digital cable types are coaxial and optical. Both commonly use the S/PDIF standard, short for Sony/Philips Digital Interface. That standard allows consumer audio equipment to send stereo PCM audio or compressed surround formats such as Dolby Digital and DTS.

In normal human terms: a digital audio cable carries the recipe for the sound, not the cooked meal. Your receiver, DAC, soundbar, or amplifier then decodes that recipe and turns it into music, movie explosions, dialogue, or whatever your neighbor is tired of hearing through the wall.

What Is a Coaxial Digital Audio Cable?

A coaxial digital audio cable looks similar to a regular RCA cable, but it is designed for digital audio transmission. Most consumer coaxial digital connections use a single RCA-style connector, often color-coded orange. The cable itself should ideally be a 75-ohm coaxial cable, because impedance matching helps reduce signal reflections and maintain stable digital transmission.

How Coaxial Digital Audio Works

Coaxial digital audio sends electrical pulses through copper. The receiving device reads those pulses as digital data. Because the signal is electrical, coaxial cables can be physically tough and reliable, especially when the cable is well shielded and the connectors fit snugly.

Coaxial is common on CD transports, older DVD players, some Blu-ray players, AV receivers, stereo amplifiers, DACs, and certain TVs. It is especially popular in two-channel hi-fi systems where a CD player or streamer sends digital audio to an external DAC.

Pros of Coaxial Digital Audio

Coaxial cables are usually durable, easy to plug in, and less fragile than optical cables. A decent coaxial cable can handle longer cable runs better than many budget optical cables. Coaxial connectors also tend to sit firmly in place, which is useful if your entertainment center has more cable chaos than a spaghetti factory.

Another benefit is compatibility with many hi-fi components. Some audio enthusiasts prefer coaxial for CD players and standalone DACs because it avoids the electrical-to-light and light-to-electrical conversion used by optical connections. Whether that creates an audible difference depends heavily on the equipment, room, speakers, and listener. In many systems, the difference is subtle or nonexistent.

Cons of Coaxial Digital Audio

Because coaxial uses an electrical connection, it can theoretically pick up electromagnetic interference or radio-frequency noise. In a well-designed home system with short cable runs, this is usually not a big problem. But if your setup includes computers, power bricks, routers, fluorescent lights, and a power strip that looks like it lost a wrestling match, interference may become more relevant.

Coaxial also creates an electrical connection between devices. In rare cases, that can contribute to ground-loop noise, although digital coaxial is generally less prone to the familiar analog hum problem than standard analog RCA audio cables.

What Is an Optical Digital Audio Cable?

An optical digital audio cable, commonly called Toslink, sends digital audio as pulses of light through a fiber-optic strand. Instead of pushing electrical data through copper, it flashes light from one end of the cable to the other. It is basically audio’s tiny lighthouse system, minus the foghorn.

How Optical Digital Audio Works

Inside an optical audio connection, the source device converts the digital electrical signal into light. The optical cable carries that light to the receiving device, which converts it back into an electrical digital signal for decoding. This design gives optical audio one major advantage: it does not conduct electricity between devices.

Optical outputs are common on TVs, soundbars, game consoles, older media boxes, AV receivers, and desktop audio gear. If you have ever connected a TV to a soundbar without HDMI ARC or eARC, there is a good chance you used optical.

Pros of Optical Digital Audio

The biggest advantage of optical audio is immunity to electrical interference. Since the signal travels as light, nearby electrical noise does not affect it the same way it can affect copper-based cables. This makes optical a smart choice when connecting a TV to a soundbar, especially when the devices are near power cables, Wi-Fi routers, computers, or other electronics.

Optical cables are also lightweight, thin, and widely available. They are simple to use: remove the tiny protective caps, line up the connector correctly, plug it in gently, and avoid bending it like you are trying to fold a taco.

Cons of Optical Digital Audio

Optical cables can be more physically delicate than coaxial cables. Sharp bends may damage the fiber, and the Toslink connector does not always feel as secure as a coaxial RCA plug. Cheap optical cables may also perform poorly over longer distances or with higher sample rates, depending on the transmitter and receiver hardware.

Another practical issue is that optical ports are disappearing from some newer devices. HDMI ARC and HDMI eARC have become more common on modern TVs and soundbars, especially for advanced home theater formats.

Coaxial vs. Optical: Sound Quality

Here is the big question: does coaxial sound better than optical, or does optical sound better than coaxial?

In most everyday setups, the honest answer is: they should sound the same when both cables are working properly and carrying the same digital format. Digital audio is not like analog audio, where cable quality can sometimes change noise levels, frequency response, or shielding behavior more obviously. With digital transmission, the receiving device either gets the data correctly or it does not.

That said, real-world audio gear is not always perfect. Jitter, clock recovery, electrical noise, optical transmitter quality, receiver design, and DAC performance can all affect results. In a revealing hi-fi system, some listeners may prefer coaxial. In a noisy home theater setup, optical may be cleaner. In a normal TV-to-soundbar setup, the difference is usually less dramatic than moving your subwoofer out of the corner where it has been shouting at the drywall.

Supported Audio Formats

Both coaxial and optical digital audio connections usually carry the same core formats because both often use S/PDIF. These include two-channel uncompressed PCM audio and compressed multichannel audio such as Dolby Digital 5.1 and DTS 5.1, depending on the devices involved.

What Coaxial and Optical Can Usually Carry

• Stereo PCM audio from a TV, CD player, streamer, or computer
• Dolby Digital 5.1 from compatible TV broadcasts, DVDs, streaming devices, or media players
• DTS 5.1 from compatible Blu-ray players, DVD players, and receivers
• Some higher-resolution stereo PCM signals, depending on hardware support

What Coaxial and Optical Usually Cannot Carry

• Dolby TrueHD
• DTS-HD Master Audio
• Lossless Dolby Atmos from Blu-ray
• Lossless DTS:X
• Uncompressed 5.1 or 7.1 PCM surround sound

This is where HDMI ARC and especially HDMI eARC enter the conversation wearing sunglasses. If you want modern surround formats, object-based audio, or lossless movie soundtracks, HDMI eARC is usually the better connection. Optical and coaxial remain useful, but they are not the best tools for every modern home theater job.

Coaxial vs. Optical for TV and Soundbar Setups

For TV-to-soundbar connections, optical is far more common than coaxial. Many TVs include an optical output, while coaxial digital outputs are less common on modern televisions. If your TV and soundbar both have optical ports and you only need stereo or Dolby Digital 5.1, optical is a clean and reliable choice.

However, if both your TV and soundbar support HDMI ARC or eARC, HDMI is usually more convenient. HDMI can pass audio and control signals, which means your TV remote may control soundbar volume. HDMI eARC also supports more advanced formats than optical.

Best Choice for a Basic Soundbar

Use optical if your soundbar is a simple 2.0, 2.1, or basic 5.1 model and your TV does not support HDMI ARC. It is easy, stable, and avoids electrical interference.

Best Choice for Dolby Atmos Soundbars

Use HDMI ARC or HDMI eARC instead of optical or coaxial. Dolby Atmos support depends on the device, app, format, and connection method, but optical is generally not the right path for modern Atmos soundbar features.

Coaxial vs. Optical for Music Listening

For music, coaxial and optical can both perform beautifully. If you are connecting a CD player, streamer, or computer to an external DAC, the best choice may depend on your system.

Coaxial is often favored in traditional hi-fi because of its strong connector, robust cable design, and compatibility with many DACs. Optical is excellent when you want electrical isolation, especially if the source is a computer or TV that may introduce noise into the audio chain.

For example, if your desktop computer sends digital audio to a DAC, optical can help isolate the DAC from electrical noise generated by the computer. If your CD transport connects to a high-quality DAC across a short distance, coaxial may be the more secure and technically elegant option.

Durability and Installation

Coaxial wins the durability contest in most rooms. It handles bends better, the connector is usually sturdier, and the cable can survive the kind of behind-the-cabinet treatment that would make an optical cable file a complaint with human resources.

Optical cables need gentler handling. Do not sharply bend them, pinch them under furniture, or force the connector into the port. Also, remember to remove the protective plastic caps from the ends before use. Many people have spent ten confusing minutes wondering why an optical cable will not fit, only to discover it is still wearing its tiny helmet.

Distance: Which Cable Works Better for Long Runs?

For short runs under 6 to 10 feet, either coaxial or optical usually works well. For longer runs, coaxial often has the advantage because a properly made 75-ohm coaxial cable can remain stable over greater distances. Optical can also work over longer distances, but cable quality and device transmitter strength matter more.

If you are running audio across a large room, buy a well-made cable and avoid the cheapest mystery cable available. You do not need a cable priced like jewelry, but you also do not want one that appears to have been assembled during a lunch break with dental floss and optimism.

Price: Do Expensive Digital Audio Cables Matter?

You do not need to spend a fortune on either coaxial or optical digital audio cables. A properly made, reasonably priced cable is enough for most systems. With digital audio, paying more does not automatically create deeper bass, silkier highs, or a saxophone player appearing in your living room.

Spend enough to get solid connectors, correct specifications, and decent build quality. Avoid damaged cables, extremely loose connectors, and suspicious products that promise “quantum audio awakening.” Your receiver is not meditating. It just needs a clean signal.

Quick Comparison Table

Which One Should You Choose?

Choose coaxial digital audio if your equipment supports it, you want a physically durable cable, or you are connecting a CD player, streamer, or transport to a DAC or receiver. Coaxial is especially attractive for stereo hi-fi systems where the connection is short, stable, and easy to manage.

Choose optical digital audio if you are connecting a TV to a soundbar, dealing with possible electrical interference, or using gear that only offers Toslink. Optical is also a great choice when you want electrical isolation between devices.

Choose HDMI ARC or eARC instead if your goal is modern home theater convenience, Dolby Atmos, lossless surround, advanced soundbar control, or one-cable simplicity between a TV and audio system.

Real-World Setup Examples

Example 1: TV to Basic Soundbar

If your TV has optical out and your soundbar has optical in, use an optical cable. Set the TV audio output to PCM for stereo soundbars or Dolby Digital if your soundbar supports 5.1. This is one of the easiest upgrades from thin TV speakers, which often sound like dialogue is being delivered through a cereal box.

Example 2: CD Player to External DAC

If both devices have coaxial digital ports, coaxial is a strong choice. It is secure, durable, and widely supported by hi-fi DACs. Optical can also work, especially if you hear noise or want electrical isolation.

Example 3: Blu-ray Player to AV Receiver

If your receiver supports HDMI, use HDMI for the best format support. If you are using an older receiver, coaxial or optical can still deliver Dolby Digital or DTS 5.1, but not lossless Dolby TrueHD or DTS-HD Master Audio.

Common Mistakes to Avoid

Using Analog RCA Instead of Digital Coaxial

A regular RCA cable may work in a pinch, but a true 75-ohm digital coaxial cable is the better choice. The connectors may look similar, but the cable design is not always the same.

Expecting Optical to Carry Every Format

Optical is excellent, but it has limits. If you want advanced surround formats from modern streaming apps, Ultra HD Blu-ray discs, or a Dolby Atmos soundbar, check whether HDMI ARC or eARC is required.

Forgetting Audio Settings

Many sound problems are caused by settings, not cables. If you hear no sound, check whether the TV or player is set to PCM, bitstream, Dolby Digital, or passthrough. A cable cannot fix a menu setting that is quietly ruining your evening.

Personal Experience: What It Is Like Using Coaxial and Optical Audio Cables

In real-world use, the best cable is often the one that works cleanly with the equipment already sitting in front of you. I have seen plenty of setups where optical was the hero simply because the TV had an optical output and the soundbar had an optical input. One cable, two clicks, and suddenly movie dialogue no longer sounded like it was hiding under a blanket. For many people, that is the entire mission.

Optical feels especially practical in living rooms. It is thin, easy to route behind a TV, and great for reducing worries about electrical noise. When connecting a TV to a soundbar, optical often gives a neat result with very little drama. The main thing is to treat the cable gently. Bend it too sharply or force the Toslink connector, and you may turn a simple setup into a tiny plastic tragedy. Also, removing the protective caps before plugging it in is a rite of passage. Almost everyone forgets once. Some of us forget twice and pretend we were “inspecting tolerances.”

Coaxial, on the other hand, feels more confident in a hi-fi rack. The connector grabs firmly, the cable feels tougher, and the setup has that satisfying old-school audio feel. When connecting a CD player to an external DAC, coaxial often feels like the natural choice. It is simple, sturdy, and dependable. In a stereo music system, I would usually try coaxial first if both devices support it. If the sound is clean and the connection is stable, there is not much reason to overthink it.

That said, optical can solve problems coaxial sometimes cannot. If a computer, TV, or streaming box introduces faint noise into the system, optical’s electrical isolation can be a lifesaver. Because it uses light instead of a conductive path, it prevents certain electrical issues from traveling between devices. This is one reason optical remains useful even though HDMI has become the big boss of modern home theater.

The biggest lesson from using both is that cable debates can get louder than the actual speakers. In many systems, swapping between coaxial and optical does not create a night-and-day sound difference. Speaker placement, room acoustics, source quality, audio settings, and the quality of the DAC usually matter more. A $20 cable correctly matched to your equipment can beat a $200 cable connected to the wrong port with the wrong settings.

My practical advice is simple: use optical for TVs and soundbars unless HDMI ARC or eARC is available and better suited to your needs. Use coaxial for CD players, transports, DACs, and traditional stereo gear when available. Do not buy the cheapest cable that looks like it came free with a haunted DVD player, but do not spend luxury-watch money either. Good digital audio is mostly about compatibility, clean setup, and sensible expectations.

Conclusion

The coaxial vs. optical digital audio cables debate does not need to become an audiophile courtroom drama. Both cables can deliver excellent digital sound. Coaxial is tough, secure, and often preferred for hi-fi components. Optical is immune to electrical interference and extremely useful for TVs, soundbars, and setups where isolation matters.

If your equipment gives you both options, choose based on your setup rather than mythology. For music-focused stereo systems, coaxial is often a great first pick. For TV audio and noise-free convenience, optical is hard to beat. For advanced home theater formats, look beyond both and use HDMI ARC or eARC when available.

In the end, the best cable is the one that carries the format you need, fits your gear, stays connected, and lets you enjoy the sound instead of crawling behind the cabinet again. Your knees will thank you.