Hooking up a subwoofer


Congratulations on choosing to use a sub-woofer with your audio-video system. Many folks use sub woofers to extend the range of audio produced from their existing speakers. Despite the claims of many manufactures, 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 they are able to reproduce some bass frequencies, there are compromises. Sub-woofers can be used on the simplest of audio systems or full-blown home theater equipment. An investment in a sub-woofer can be the start of many audio upgrades that won't end with the original sub-woofer being thrown out.


Sub woofer types

Sub-woofers come in two categories; self-powered units and those powered by an external amplifier. Powered sub-woofers 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 plug into electricity and some can automatically come on when sound is detected.

Passive sub-woofers 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 sub-woofer. Most of the time, they only have a low-level audio output. Smarthome has a dedicated Subwoofer Amplifier to drive these units.

Selecting the location

Start installing your new sub-woofer by selecting a location for the unit. For the remaindered of this how-to project, we'll use the powered sub-woofer in our discussion. Low frequency or bass sounds are the most omni directional of all the audio frequencies we can hear. As sounds get in the higher mid-range and tweeter frequencies, they become more directional so speaker location and pointing are an important consideration. Start by placing your powered sub-woofer 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 sub-woofer. If you don't like the sound after the initial placement, move the unit. There are few rules about sub-woofer placement; it's what sounds good to you!

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Cable hookup

Next there needs to be hook-up cables between the sub-woofer and the audio system. Many of today's home stereo receivers have a dedicated audio output for sub-woofers. 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 sub-woofer. 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 near-by electricity lines. I suggests using the Monster Cable Interlink Audio Cables. These manufacture have gone to extremes to build an excellent cable that resists external noise leaking into the cable.

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If your stereo does not have a sub-woofer output jack, there is an alternate hookup method. Some powered sub-woofers 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 "B - Speakers" to the push terminals on the sub-woofer. Inside the speaker, the amplification circuitry will combine both channels to mono, extract the bass frequencies, and amplify the sound for the sub-woofer speaker.