Primer: Hooking Up a Subwoofer


Feb. 01, 2009 — by .(JavaScript must be enabled to view this email address)

Congratulations on choosing to use a subwoofer with your audio/video system. Many people use subwoofers to extend the range of audio produced from their existing speakers. Despite the claims of many manufacturers, most “full-range” speakers don’t do a very good job reproducing the low-frequency sound effects found with today’s DVDs and Digital Satellite Systems. While these speakers are able to reproduce some bass frequencies, there are compromises. Subwoofers can be used on the simplest of audio systems or full-blown home theater equipment.

Subwoofer Types
Subwoofers come in two categories: self-powered units and those powered by an external amplifier. Powered subwoofers are usually cube-shaped boxes with one or two speakers inside. Internally, they contain circuitry to amplify the incoming audio signal. They may also have controls and switches on the exterior to adjust the sound volume and other features like the range of sounds reproduced. These units require electricity, and some can automatically come on when sound is detected.

Passive subwoofers are basically just the speaker element. These units are often designed to be installed in a wall or ceiling. Like your existing room speakers, they too will need to be powered by an amplifier. Most stereos and home theater receivers don’t have dedicated amplification circuitry to drive a subwoofer. Most of the time, they only have a low-level audio output.

Selecting the Location
Start installing your new subwoofer by selecting a location for the unit. Low-frequency or bass sounds are the most omnidirectional of all the audio frequencies you can hear. As sounds get in the higher midrange and tweeter frequencies, they become more directional, so speaker location and pointing are an important consideration. Start by placing your powered subwoofer near the front of your home theater system. A few feet to the left or right of the screen is a good starting point. Keep in mind that you will need to run electricity, audio cables or speaker wires to the subwoofer. If you don’t like the sound after the initial placement, move the unit. There are few rules about subwoofer placement; it’s what sounds good to you!

Cable Hookup
Next there need to be hook-up cables between the subwoofer and the audio system. Many of today’s home stereo receivers have a dedicated audio output for subwoofers. If your receiver has this output, it will carry both channels of a stereo signal. Connect a good-quality audio cable between the sub-out jack and the input jack on the subwoofer. Be sure to use a good cable with quality shielding. Since this unit is able to easily reproduce 60 and 120 cycle sounds, a poorly shielded cable could pick up hum from nearby electricity lines. Smarthome suggests using the Monster Cable Interlink 400.

If your stereo does not have a subwoofer output jack, there is an alternate hookup method. Some powered subwoofers are able to take the speaker-level signals from the amp and extract the bass sounds. Run some speaker cable from the left and right outputs of the speakers to the push terminals on the subwoofer. Inside the speaker, the amplification circuitry will combine both channels to mono, extract the bass frequencies, and amplify the sound for the subwoofer speaker.

Crank It Up
At this point you are ready to enjoy your first experience with loud and clear bass sounds. For some television programming, like a news program, the subwoofer can be switched off unless you need to hear James Earl Jones announce “This is CNN” with ultimate clarity.

For even more earth-shaking fun, check out Smarthome’s Tactile Transducers. These units are like subwoofers but are designed to produce only vibrations for the listener. With these units bolted to your sofa, easy chair, or floor joists, you’ll feel the sound in your bones. Imagine the vibrations of the rocket launch in Apollo 13, the rumble of a Harley in Terminator 2, and the destruction of Paris by an asteroid in Armageddon. Talk about fun, tactile transducers turn your home into the equivalent of a theme park ride!

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