Here at Aperion Audio we’ve logged thousands of hours talking to our customers about their speakers and a good chunk of that time has been concerned with helping them sort out issues with their set ups. After a while, these challenges fall into a few different categories that can usually be quickly diagnosed and resolved. We figured we would share a few of the more common complications with you, in hopes that reading our guide will help you find an easy and painless solution, should one of the following scenarios happen to you.
Problem: Humming Sound from Subwoofer
The subwoofers we sell, along with most you can find out there in the market, are powered subs. A powered sub has its own amplifier built right into the cabinet. That’s great because it allows for the power you need to push a woofer with more surface area the larger distances, relatively speaking, that are necessary to create low frequency sound waves. However, it also means that the subwoofer amplifier can amplify things you don’t want to hear, like a ground loop hum. That’s usually what is going on when you hear an annoying humming sound coming from your sub. Understanding the root cause of a ground loop hum is somewhat technical, but suffice to say it’s basically the difference in voltage potentials between your sub and another component in your system which is causing noise in the form of a distracting
50-60Hz hum.
Most Common Solution: You can eliminate the hum by lifting the ground of your sub and using a three prong to two prong plug adapter. But that removes the ground protection on the outlet, so of course we would NEVER suggest such a reckless and extremely easy fix. Instead, you can isolate the source of the loop by unplugging your components one by one. Start with your cable box as that is a common culprit. Once you find the offending component, you can put a ground loop isolator in between the component and the wall outlet. That should cause the ground loop to become inaudible and you can regain your grip on sanity.
Problem: Receiver Shutting Down
You’re watching your favorite TV show or that movie you’ve been looking forward to and all of the sudden your A/V 
receiver completely powers down and you’re left in stunned silence. What just happened? We hear about this one all the time and people often think it’s because the speakers are drawing too much power from the receiver or there’s an impedance mismatch between the speakers and receiver. While both of those can happen, the vast majority of the time it’s merely due to the speaker wire and a stray strand of copper from one conductor is touching the copper from the other conductor.
Most Common Solution: Make sure there are no loose speaker wires both on the back of the receiver and at the speaker binding posts. If just one strand of copper from one conductor touches the other one it will create a short and send your receiver into protection mode. Using banana plugs can help, but not guarantee, that this nuisance will not happen in the first place.
Problem: Scratchy Sound from Speaker
This one is really no fun because it’s usually pretty intermittent and could be a variety of different things. The first thing to do is to figure out just exactly what is causing that sound, it could be a faulty speaker and it also could be something else. In order to do that, try swapping the right and left speaker positions.
Common Solutions #1: If the sound doesn’t follow the speaker and stays on the same side, it may in fact just be an artifact in the source material. There are all kinds of tiny glitches either in the soundtrack of a show or movie or from the broadcast if you are watching live TV. For this reason it’s important to try out a variety of material as well when troubleshooting a problem. Another possible reason if the sound stays on the same side is interference from the wiring run. Make sure that the speaker wire always crosses any AC power lines inside a wall at a 90 degree angle to minimize crosstalk between them.
Common Solution #2: If the sound follows the speaker and is now on the other side, then you do indeed have something going on with the speaker itself. You may have a blown driver, but to make sure, it’s a good idea to do a little further testing. When a tweeter blows it usually will just go completely silent as the voice coil is typically completely disconnected from the speaker’s internal wiring. So if the tweeter is still producing sound, then it’s probably not the issue. Woofers on the other hand can blow and produce a distorted scratchy sound. The best way to test for this is to press in gently on the exact center of the woofer. When you do this, the woofer should be nice and springy and move back and forth freely. Make sure your finger is not slightly to the side of the woofer or this will not be the case. If you’re pressing right on the center and the woofer is resisting your push and/or making a scraping sound, then you probably have a blown woofer. Contact the manufacturer to see if it can be replaced.
Problem: Subwoofer is Producing No Sound
Bass management in your receiver tends to be more involved than the settings for your other speakers. Because of that, if you don’t have the subwoofer settings dialed in correctly, your subwoofer will simply sit cold and dormant, silently mocking you. But fear not, changing a couple receiver settings will address almost all of the cases when the sub produces no sound. Unless of course you forgot to plug in or turn it on, in which case, don’t fret, you aren’t the only one to have made this mistake.
Common Solutions: First get into the speakers section in the receiver. From there you will usually see a subsection labeled Speaker Config. Once you get in there, make sure you have let your receiver know that you have a subwoofer by setting the subwoofer setting to “yes” or sometimes it will be “one” or “two” depending on how many subwoofers are connected. For the next one, in most receivers it will only apply if you have set your fronts to “Large.” In most cases we don’t recommend setting your fronts to large, for reasons that have been previously been explained here. But a lot of people set their fronts to large anyway either because they don’t know what the setting does or they prefer more bass. When the fronts are set to large, a full range signal down to 20 Hz is sent to the front speakers. So in order to get output from the sub, you’ll need to get into the Subwoofer submenu of your receiver and enable a setting that is called “LFE + Main”, “Plus”, “Both” or “DoubleBass”. When you’ve enabled this setting, you are telling your receiver to send the bass signal to both the front speakers as well as the subwoofer and poof, your subwoofer begins to output sound and all is well in your home theater.
That covers the audio pitfalls that we hear about on an almost daily basis. Hopefully this article helped you identify the source of your trouble and find the solution. If you have a weird one, feel free to give us a call, send an e-mail or start a live chat and we’ll be happy to help and get you back on track!