You sit down to relax and listen but notice something is off.
A conspicuous, persistent hum emanates from the subwoofer, and it shows no signs of going away.
In this article, we show you how to fix it.
Dario Petrović / Getty Images
If the first suggestion doesn’t work, try one of the others.
Change the polarity of the subwoofer’s connection.
Sometimes, one prong is wider than the other, which may prevent the reversal.
In such situations, use an AC ground adapter to reverse the polarity.
Most of these adapters have uniform-sized prongs and are available at local home improvement stores.
It could be some other two-prong AC plug.
One by one, reverse the orientation of the other plugs to see if it makes a difference.
Space cables apart so the electrical fields created by moving current don’t interfere with each other.
If you could’t separate them a sufficient distance, upgrade the audio cables to ones with more effective shielding.
Use an audio isolation transformer.
If the previous grounding techniques haven’t worked, consider purchasing and installing an audio isolation transformer.
Many are designed for powered subwoofers and connect in line with the cables.
They instantly resolve ground loops.
This 60-hertz hum is a result of being plugged into an AC wall outlet.
Sometimes the hum is noticeable; sometimes, it takes some focused listening to notice.
Usually, all it takes is a change in the way the subwoofer connects to power.
