Thumping/Humming Noise in Sub

Thumping or constant high pitched/squealing sounds may be symptoms of an amplifier malfunctioning. 

If you're experiencing any of these, please contact our Product Support team for assistance.

For ways to contact our Product Support team, please see our article - How To Submit

If you notice that your subwoofer is humming constantly, then it may require a bit more troubleshooting to find the cause.

It is possible that the issue is being caused by a "ground loop". Ground loops can often be resolved without spending any money on the problem. The trick is that one needs all of the grounds on all of the gear to have the same potential. Sometimes this is as simple as getting them all plugged in to the same power circuit; sometimes it's a matter of making sure that you're only using modern, three-wire, earth-grounded circuits at all points in your system rather than using old two-prong ungrounded circuits. Changing where things are plugged in, making sure your home power circuits are all properly grounded (an outlet-checker from the hardware store can be handy!), and the like will often resolve the issue. Beyond that, if your home wiring has serious grounding issues, you may need the aid of an electrician.

Although the best and most permanent way to eliminate ground loop hum is by fixing the underlying grounding problem, another simpler way to resolve the problem is to insert an isolation transformer in your subwoofer line to break the ground connection between your source and your subwoofer.

One other method of resolving this "ground hum" is to get a directional/shielded subwoofer cable. These work using metal layers to reduce the amount of RF and EMI noise. For some, there is even an integrated chassis ground connector to help eliminate ground loop hum.

Here are some examples of directional/shielded subwoofer cables:

AudioQuest Black Lab

Note: When you plug in these directional cables, make sure that the arrow is pointing towards the subwoofer, not the receiver.

Monoprice Shielded Cable

If you find that your home has no grounding losses and that the cable/isolation transformer does not resolve either, then the subwoofer's internal amplifier may need repaired or replaced. If you need to contact us regarding this, please see our article How To Submit for assistance.