Subwoofer hum is a potential issue that can be caused by a variety or combination of sources. Finding the solution is usually a complex game of trial and error, depending entirely on the root cause. In order to save yourself some initial headache, please try the troubleshooting guide below:
The ground current is shared throughout your home and can introduce feedback to a subwoofer, resulting in a hum. Try each step, and if the hum remains, move to the next step.
Step 1) Try plugging the subwoofer into a different electrical outlet. This is the easiest way to address a potential ground issue in your home, and you should notice a change in the amplitude of the hum.
Step 2) Try plugging your subwoofer power cord into the same power strip as your other electrical components. This may reduce a hum if not eliminate it. Use an extension cord if necessary.
Step 3) Try connecting the power cable to a travel adapter without a grounding pin. This way the subwoofer is no longer grounded, and shouldn't be affected. This is safe for Arendal Sound subwoofers as they are double insulated, and the only issue you may theoretically experience is that the amplifier could be susceptible to radio frequency noise.
Step 4) Try using a hum eliminator. These tend to be quite effective.
If the above steps do not work, your RCA cable might be the culprit (skip this section if using XLR cables).
Power Cord Interference
If the "Ground Issue" steps above do not help, you may have power cord interference. Power cords in close proximity to speaker cables can introduce distortion to the cable signal, resulting in a hum from your subwoofer. RCA cables are more susceptible to signal distortion since they are unbalanced, whereas XLR cables are much better thanks to their balanced design.
Step 5) Separate your RCA cables from your power cables as much as possible. You can use search "power cable management" online for ideas.
Step 6) Try using a shorter RCA cable.
Step 7) Change to an RCA cable with high-quality shielding; these better protect the input signal from outside interference.
Step 8) Use balanced cables. It is much more difficult to induce a subwoofer hum when using balanced, or XLR cables.
For many, XLR cables are not featured on their AVR/processor and they can only use RCA cables. In this case we still have a few more options.
At this stage it is likely that one of your components is inducing the hum in your subwoofer, due to a difference in grounding potential.
Step 9) Disconnect each component cable one at a time until the hum stops. Connect a hum eliminator/isolation transformer for that specific type of cable.
If these solutions are not effective, feel free to reach out and our customer support team will happily do our best to help find a solution.