We all know that a subwoofer is an integral part of any home theatre setup. Surround sound and 3D audio is incredibly immersive, but without the rumble of a subwoofer, movies lose a lot of their magic. Have you thought about adding a subwoofer to your home audio system? Here are a few best practices for adding a subwoofer to your home’s audio system.
Does your home audio system lack bass?
Many people have a system that’s used primarily for listening to music. One of the more popular configurations these days is a stereo system with two speakers, perfect for enjoying records on a turntable, CDs, or your favourite music streaming service. Many people opt for a pair of bookshelf speakers, which offer that coveted stereo sound without taking up a lot of space.
The downside of home audio systems that use compact speakers—even very good ones—is a lack of bass response. The sound may be clean and in stereo, but it often lacks that low-end punch that makes everything sound perfect. The good news is it’s easy to fix the issue using the star of the home theatre setup – a subwoofer.
How a subwoofer adds bass
If your home audio system is equipped with a pair of large tower speakers, you may already have that extra bass oomph you’re looking for. If you have bookshelf speakers, you’ll find the limits of their ability to produce the same low bass frequency because they are far smaller. Bass is low frequency sound waves, and to generate those low frequency waves you need a large driver capable of moving large volumes of air.
Subwoofers are built around large drivers. They are typically 8-inches, 10-inches, or 12-inches in diameter. In comparison, the woofer—the driver responsible for low and mid-frequency sound in most bookshelf speakers—may be anywhere from 4-inches to 6-inches. Many types of bookshelf speakers are designed with a dual driver setup, and the woofer is working hard to cover both the low-end and the mid range.
Adding a subwoofer into the mix means your audio system now has a speaker that’s solely dedicated to low frequency sound, and it’s equipped with a big driver that’s capable of producing those ultra lows. In a home theatre system, this adds realism to sound effects like explosions and revving engines. It gives depth and adds subsonic rumble, and the subwoofer adds new prominence and depth to instruments like the bass guitar and drums. The bass may sound decent in a compact stereo listening system, especially one equipped with a good pair of bookshelf speakers, but the difference a subwoofer makes is like night and day.
For more information on speakers, take a look at the home audio speaker buying guide.
Tips for making the most of your subwoofer
There are a few tips I can share to help you make the most of your subwoofer.
1. Use the right cables
There are two ways a subwoofer can be connected to an audio system and each method requires different audio cables. Some receivers and amplifiers have a subwoofer output jack. It’s usually labelled SUB OUT. In this case, connecting is as easy as using an RCA subwoofer cable to connect to the LFE or Line Input on the subwoofer.
However, many stereo receivers and amplifiers lack that subwoofer output. Especially systems that are used primarily for listening to records. Many of these setups use a 2-channel stereo receiver or amplifier, often a vintage model that pre-dates subwoofers. However, these systems can still be used with a subwoofer. You’ll need to choose a subwoofer that offers speaker-level input and output. This basically replicates the speaker jacks you see on the back of your receiver.
To connect the subwoofer in this case, you disconnect your speakers from the receiver and plug them into the Speaker Outputs on the subwoofer (they use the same left and right, black and red setup). Then, you run a new set of speaker cables from the Speaker Input on the subwoofer to the Speaker Outputs on your receiver. It’s recommended you use fairly heavy-duty speaker wire. Look for 12-gauge to 16-gauge speaker wire for the best connection.
2. Put you subwoofer in a prime position
Positioning the subwoofer is important and can be a bit of a challenge. Space is often the biggest issue to deal with because subwoofers are big. They have large drivers, but also large enclosures to give those drivers room to move. Most subwoofers are powered, which means you need to be within range of an electrical outlet. The enclosures also require space for an amplifier (with powered subwoofers) and other electronics. Amplifier size can have a lot to do with whether you choose a small subwoofer or a large one.
3. Decide if you need 2 subwoofers
The usual setup in an audio system setup is to use a single subwoofer and to position it between the two speakers, ideally no more than a few metres away from the speakers. Set up like this, the bass will sound as though it is coming from the speakers, not the subwoofer. Technically your setup won’t be true stereo for the low frequency notes, but you shouldn’t be able to tell. In this case, you don’t need two subwoofers, although some people do choose to go that route.
The subwoofer is often placed near a wall. Models that have front bass ports can be placed pretty much against the wall. Units with rear bass ports need to be kept some distance from the wall or the airflow out of the vent will be disrupted, and that can affect the sound quality. In my own office setup I have a pair of bookshelf speakers sitting on bookshelves and the subwoofer is between them, hidden under my desk.
Adjusting subwoofer settings is the key to great performance
Connecting the subwoofer and positioning it are two basic steps to making the most of your subwoofer, but now we get down to fine-tuning. This is the step that will make or break your listening experience.
Home theatre receivers usually handle the subwoofer fine-tuning on their own, or they have the technology to guide you through the process. When you’re connecting to a stereo receiver (especially one that lacks a dedicated subwoofer output), it’s time to get manual. You may have to fuss with these settings for a few minutes to find the perfect combination.
Fine tuning your subwoofer
On the back of the subwoofer you’ll find a crossover dial. It may also be called low pass. This is the setting that controls the point at which the signal from your stereo system is handled by the subwoofer instead of the speakers. Anything above the frequency you choose goes to your speakers, as usual. Anything below that level is now handled by the subwoofer.
The level you choose is going to depend on what type of speakers you have. For bookshelf speakers with a small woofer that’s 4 inches or less, you’ll want to set the crossover fairly high. I recommend trying 120Hz. As the driver gets larger, the crossover can be lower, for example, 100Hz for a 5-inch woofer. Once it’s set you should listen to music that features bass. If female vocals sound too deep, the crossover is set too high and you should dial it back a bit. If male vocals or a bass guitar sound thin, you can increase the crossover frequency.
The volume controls how loud the subwoofer is in relation to your other speakers. Have it too loud and the bass will start to boom and distort, especially as the music volume is turned up. If it’s too low the music will sound thin, especially as it gets louder. You should try setting the subwoofer volume at 50% and adjust from there.
Phase is a switch control (0 or 180 degrees) that ensures the subwoofer and woofers in your primary speakers are operating together in sync. You should listen to music that features a lot of bass while flipping between a phase of 0 and 180. Leave it at the one that sounds best. If you can’t tell the difference, go with 0 degrees.
Do I need a subwoofer when I have a sound bar?
Many people use a sound bar instead of a traditional stereo system. They’re great space-savers for TVs, but you might not have known they can do double-duty as a home audio system. Do you need to use a subwoofer with a sound bar? It’s up to you, but for home theatre, gaming, and music-listening applications, the audio is always going to sound better with a subwoofer.
I have an older but very capable soundbar in my rec room. It’s equipped with 21 small 1.5-inch drivers and a pair of 4-inch woofers. When I first installed it I thought it sounded pretty good. However, it wasn’t until I picked up the matching subwoofer that the system fully lived up to its potential. It’s the subwoofer that brought the missing rumble and provided the low end for window-rattling bass.
The complication is that many soundbars lack subwoofer or speaker output. If you already own a subwoofer, check its outputs—it may have an output, or it’s also possible the manufacturer may sell a subwoofer specifically for use with it.
The good news is if you are shopping for a new soundbar, many brands including Samsung, Bose, JBL, Polk, Sony, Sonos, Klipsch, and Mission have soundbar packages that include a subwoofer.
Troubleshooting issues with your subwoofer
Here are a few common issues you may have when connecting a subwoofer.
Problem: audio is too boomy, distorted, or thin
If you’re lucky, everything will sound perfect when you get the subwoofer connected to your home audio system. However, it’s just as likely that there will be some tweaking required. If the audio seems boomy, distorted or thin, it’s time to fiddle with the position of the subwoofer and the crossover, volume, and phase settings.
Problem: my subwoofer is really vibrating
A subwoofer moves a lot of air, and sometimes that can cause vibration, especially at higher volumes. In my case, the subwoofer came with feet to help dampen vibration. However, on a wooden floor the vibration was still enough to rattle objects on my bookcases. It goes without saying that vibration wasn’t just annoying – it was really bad news for my turntable.
When vibration is an issue, the subwoofer needs to be isolated from the floor and/or walls. There are rubber and even shock-mount speaker feet designed for this purpose. I used a heavy sound isolation platform with integrated shock-absorbent feet. I’ve found that this setup completely eliminated the vibration.
Problem: my subwoofer is humming
Sometimes a low-frequency background hum can be heard when the subwoofer is powered up. If you experience this, check the speaker cables and connections between the subwoofer and the amplifier. A bad connection or damaged cable can cause hum. The other cause is usually electrical. Try plugging the subwoofer into the same electrical outlet as the amplifier (using a power bar if necessary). If the two devices are already plugged into the same outlet, try plugging the soundbar into an outlet on a different circuit.
Enjoy your home audio system with its improved subwoofer bass performance
Once you’ve set up your subwoofer it’s time to sit back and enjoy listening to music that sounds the way it was intended to, complete with powerful bass. Pink Floyd has never sounded better on my system since I installed a subwoofer.
The great thing about a subwoofer is that you can completely upgrade your audio system’s sound without the expense and hassle of replacing your existing speakers and components. You don’t need to go with big tower speakers either – you can build an audio system around compact bookshelf speakers or even make a soundbar sound impressive.
You can find a subwoofer and speakers for your audio setup at Best Buy.