For many years, subwoofers have used RCA cables to connect to receivers and amps. Since then, these basic cables have been modified to be more complex and powerful with durable materials and special features. These cables are called subwoofer cables. RCA cables and subwoofer cables are the most common connections for subwoofers.
However, many homes have coax running through and you may be considering if you can use coax for subwoofer wires or as subwoofer cables.
Yes, you can use coaxial cables to connect your subwoofer. This is a great idea if you need to connect your subwoofer over long distances. For example, if your receiver/amp is in a different room than your subwoofer, using coaxial is a good choice. While you can connect a subwoofer to your receiver using a coaxial cable longer than say 20 feet and not experience problems, you can’t do the same with an RCA cable. RCA would be susceptible to electromagnetic interference (noise) especially if it crosses household electrical wires which can result in a subwoofer hum.
Let’s find out more information about using coaxial cables as a subwoofer wire.
What Are RCA Cables?
These are very common cables that are widely used in most sound systems.
What Is A Subwoofer Cable?
A subwoofer cable connects an AV receiver or audio amplifier to a subwoofer delivering low-frequency sound signals up to 100 Hz (bass signals).
Some of these cables can also carry video signals and you will see them labeled as composite video and digital coaxial cables.
Now in some cases, a subwoofer is simple enough to only require a pair of speaker wires and 1/4″ jacks.
Many people connect their receiver to their sub with basic speaker wires. Other subwoofers require RCA connectors or subwoofer cables which are really RCA connectors with special features.
What are these special features? Well, subwoofer cables are RCA cables that are modified to reduce unwanted noise.
This is why they are may have tighter woven fibers in the mesh of the shield or a second or third shield made of mesh or foil.
Another modification may be gold plating. Gold plating the connectors on a subwoofer cable improves conductivity and prevents corrosion.
Why When To Use Coax As Subwoofer Wire
Why don’t you just get a subwoofer wire? Well, you could very well do that, but it will be difficult to find subwoofer cables in stores over 50 feet, especially if you are seeking brand names. Additionally, it will be quite expensive if you find one!
So, at what length should you go for coax? Well, we do recommend that you should go for coax when you have to run the sub cable for at least 40 feet.
Here are some reasons why you can use coax as subwoofer cables:
- In some cases, coax is better shielded than some subwoofer cables
- For long runs, coaxial is a lot cheaper than subwoofer cables
- Coax is 75ohm just like dedicated subwoofer interconnects
- For pre-wire installs.Many people use it for my “rough-in” pre-wire installs all the time. For this purpose, you can choose several different types and sizes such as the RG59 or Quad-shield RG6
Best Types of Coax To Use As Subwoofer Cables
In general, coax has an impedance of 50 ohms or 75 ohms. 75ohm coax will work great for your subwoofer; just like yellow video composite interconnects as well as digital “coax” digital connections.
If you are looking for coaxial to use for subwoofer cables, then the RG-6 for my Paradigm pw-2200 is a great choice. You can get it on Amazon here. You can get the up to 250′ long.
How To Connect Your Subwoofer To an Amplifier or Receiver WIth Coax
Here is a simple way to go about connecting your subwoofer to an amplifier or receiver with coaxial cables:
When doing this, however, don’t use a crip on the connector because this can sometimes pierce the jacket/braid or kink and cause feedback hum.
Connecting RG-6 vs RG-59 Coxial Cables
If you have RG-6 or RG-59 cable, the first step is to get the connectors for RG-6 or RG-59 respectively.
Now ensure that the center conductor wrapped in plastic is attached to the center male pin on the connector.
In addition, the shield should attach to the body. Ensure you wire the cable like this at both ends and also ensure that the wires aren’t shorted, that is very important.
Once you have done that, it is time to connect to the subwoofer. You will need to connect the cable to the red input of the sub. For better bass performance, you should use a “y” and attach it to “L” and “R” on your sub.
Subwoofer Cale and Coax Impedance
As we mentioned before, subwoofer cables and other RCA audio interconnects have no defined characteristic impedance, however, the most reasonably priced ones will have an impedance of about 75 ohms. In general, most subwoofer cables will also have an impedance of 75 ohms.
This is why, if you look up a “subwoofer” or digital coax cable on almost any site, they will specifically say 75ohm.
However, if you look up an RCA cable on those same sites they will not specify an impedance rating.
Why is this? Well, it comes down to audio electronics really. Devices that specify 75ohm impedance (or any other ohm rating) do so because they provide a matched input/output impedance.
This is why your cable box or TV has a 75ohm input impedance for DACs and other digital devices with coax (S/PDIF) inputs.
For regular subwoofers and amps, the input impedance is in the 10k-200Kohm range. However, the source impedance for devices that feed these subs and amps (e.g players, tuners, preamp, etc.), is normally in the 100-1kohm range.
What If My Sub Coax Cable Is Not Working?
If your subwoofer coax cable is not working, there are some steps you need to take to troubleshoot:
- Check your connections on the coax cable
- Make sure none of the wires are frayed and make sure the shield is not touching the center conductor
Using coax for subwoofer cables is a good idea over long runs. When there is a good distance between your AV receiver or amplifier and your sub, coaxial cables will work well because they are normally shielded better than other types of cables.