In this guide we look into one of the highest audio quality connection options available for speakers, which traces its earliest use as far back as the 1850s: the coaxial speaker cable.
Coaxial cable technology has stood the test of time.
Countless technological applications have introduced, replaced, or still use them, including in many high-end applications where quality matters.
Before we look at how coaxial speaker cables can give exceptional audio quality (something we know is particularly important to audiophiles like jazz fans!) let’s take a look at how this technology works…
What’s a Coaxial Cable?
If you boil it down to its bare minimum functionality, a coaxial cable is a shielded and insulated electric conducting cable.
These cables transmit both analog and digital electric signals over radio frequencies from 20 kHz to 300 GHz.
Often referred to as just ‘coax’, these cables come in a wide variety of types with various connectors. You have probably used multiple types of coaxial cables without realising it.
People often refer to coaxial cables by their connection type like “RCA” or “XLR.”
The “coaxial” part is the cable itself between the connectors. In this case, “RCA” is not “XLR” but “RCA” and “XLR” both use a coaxial cable.
What is a Coax Cable Used for?
Coaxial cables provide a physical connection to send radio signals between a transmitter and a receiver.
Telegraph technology is an example of a coaxial cable early adopter: telecommunications companies used a coaxial cable to transmit telegraphs over long distances.
Coaxial cables entered the home through technology including HAM radio, video equipment, cable television, and audio systems.
Prior to HDMI, TVs commonly used coaxial cables to receive both video and audio signals from devices like VCRs, DVD players, cable boxes, and video game consoles over composite and component connections.
If you receive cable TV or internet, your provider delivers that service via coaxial cable.
The audio-exclusive coaxial cable uses are wide-reaching:
- Home stereo systems (including connecting to speakers).
- Microphone-based audio recording.
- Connecting electric music instruments to amplifiers.
What Makes a Coaxial Cable?
While there are several types of coaxial cables with unique design alterations for specific uses, all coaxial cables have four main components. From outside to the centre, those components are:
A protective plastic jacket
The cable’s exterior serves no purpose in transferring information, but instead protects the interior parts of the cable which handle transferring the signal and protecting that signal from interference.
A woven copper metallic shield
As its name implies, this part shields the signal from radio wave interference. Unless you’re far away from society, chances are you have dozens, if not hundreds of nearby devices that are transmitting radio signals.
Unless you’re reading this on printed paper, the device you’re using is emitting and receiving radio waves.
The inner dielectric insulator
This part of the cable doesn’t do anything and that’s the entire point. The insulator exists to separate the metallic shield from the core wire.
The centre core
This is the part that does the actual work: it carries the signal and acts as an electrical grounding for the cable, These are usually made of copper, but may be steel with copper wire coating.
The Pros and Cons of Coaxial Cables
As with any technology, an honest sales pitch needs to include a list of both pros and cons.
Coaxial Cable Pros:
- Low signal loss
- Excellent quality over short distances
- Durable cables
Coaxial Cable Cons:
- Bulky cables
- Signal loss over long distances
- Signal loss at the connection
Using Coaxial as a Speaker Cable
Now that we’ve established what a coaxial cable is, what they’re used for, and what advantages they offer, it’s time to narrow in on what makes them an excellent choice for speaker cables.
A coax speaker cable provides a durable option to send professional-level audio signals from an amplifier or a receiver to speakers.
Many audio systems use RCA coaxial cables to connect to an externally powered subwoofer. If you already know how to attach your own connectors to a speaker cable, you’re already familiar with the process needed to assemble coaxial speaker cables.
It’s something you can do manually by cutting off the connectors, removing shielding, and winding the braiding into a single thread between the two.
The Pros and Cons of Coaxial Speaker Cables
Coaxial cables are an excellent option to carry the signal from your receiver/amplifier to your speakers because they carry high-frequency signals with minimal interference
Coaxial Speaker Cable Pros:
- Provides professional-level audio quality with high-speed data transfer
- Signal degradation is a non-issue with the lengths needed for home audio systems
- Cables are considerably durable
- Excellent protection from interference or noise from other signals
- Easy to install
Coaxial Speaker Cable Cons:
- Existing “out-of-the-box” speaker cable options may be good enough for your needs
- Signal loss is a problem with very long cables.
- Cables are harder to conceal because they are bulky
- Heavier and less flexible than other options
Impedance is an important concept to consider when using coaxial speaker cables. If you have too little or too much the audio quality will greatly suffer.
Use Coaxial cables rated at 75 Ohms impedance for speaker connections.
Impedance measures the total electrical resistance of the cable. Higher impedance equates to better sound quality.
Impedance is a bigger issue with digital than analog because analog will more or less pass through, although the quality can suffer With digital, it’s all or nothing.
The DIY Process
If your speakers support RCA or XLR connectors, you’re in luck because you can easily find out-of-the-box solutions to connect to your speakers via coaxial cable.
If not, you’re going to need to take a DIY approach to attach the coaxial cable to the speakers…
You can find many video tutorials to walk through the process online. The basic steps are as follows:
- Measure the distance between the receiver/amplifier and the speaker. Measure it twice just to be safe. If you’re replacing an existing cable, you can use that as a guide for the right length.
- Cut the coaxial cable to the measured length.
- Remove the plastic protective layer with a utility knife or a razor blade, with enough room to attach the connector. This may be as little as a half-inch or as much as an inch-and-a-half. Try to use as little space as possible to make the connection because the more you expose the more signal loss you risk.
- Unwind the braided shield from the cable and twist it into its own wire-like end. This creates the “black” connector.
- Cut and remove the insulator from the cable slightly above where you removed the plastic protective layer and shield. Be careful not to damage the core. This creates the “red” connector.
- Repeat steps 3, 4, and 5 for the other side.
- Connect the exposed core speaker wire to the red connector on the speaker and the red connector on the receiver respectively.
- Connect the twisted braided shield to the black connector on the speaker and the black connector on the receiver respectively.
Other more complicated techniques use unique cables for both the red and black connectors on the speakers.
There are two types of coaxial cable construction that work with coaxial speaker cables: flexible coaxial and semirigid coaxial. You can tell the two apart easily because as their names imply, flexible coaxial bends much more easily.
However, semirigid coaxial provides superior shielding for less interference.
While semirigid is the better option for optimal audio quality, you can get good results with flexible coax which can be much easier to bend into shape to make the connection.
The Triax, dual coax, and twin axial cable types work too, but their additional features can complicate the process without providing viable results.
About Coaxial Digital Audio Cables
Your audio system may already be using coaxial cables to communicate between devices. The single cable carrying digital audio data that are split into multiple analog channels is not a sound quality bottleneck.
The digital coaxial cable connection is playing by a different set of rules. While physically identical to RCA cables, the difference between RCA and Coaxial Digital Audio is the former transmits information in analog whereas the latter does it digitally.
Digital transmission can send considerably more information between devices while using the same amount of radio wave bandwidth.
Coaxial Digital Audio Cables have two advantages over TOSLINK optical cable solutions: the former is much more durable and works well over distances greater than 15 feet. TOSLINK cables can actually break by bending.
Coaxial speaker cables provide a professional-level sound through an exceptionally durable connection. If you’re experiencing major issues with signal noise or interference, coaxial speaker cables may take care of the problem.