A powered subwoofer complements any 5.1 or 7.1 Dolby digital encoding system. Dual subwoofers, as in 5.2 and 7.2 surround sound systems, bring on additional depth of sound at the lower end of the audio spectrum. Although the signal output from a powered subwoofer is non-directional, proper speaker placement is nevertheless important in avoiding sound wave canceling and other problems. Before you begin, check to make sure your AV receiver has 5.2 or 7.2 output capability; it should be clearly stated in your owner’s manual, but if not you can call the manufacturer or place of purchase.
Arrange the four or six surround sound speakers as per the diagrams supplied in your AV receiver user manual or the suggested layout supplied with your speakers. The center channel always sits directly under the TV screen in a 5.2 or a 7.2 system. Use 18-gauge color-coded speaker wire to connect your speakers to your AV receiver’s front, rear and center channels.
Select the general location for your two powered subwoofers. Placement should be near an 110 volt AC outlet. The subwoofers need not be directly across from one another. One should be towards the front of the room and the other on the opposite side to the rear, with the seating area in between.
Connect the powered subwoofers to your AV receiver. Since powered subwoofers contain their own amplifiers, use a medium to heavy shielded cable fitted with an RCA phono plug at each end, available in varying lengths from both brick and mortar and Internet retailers. Use the shortest possible cable to do the job.
Plug your subwoofers into the 110 volt AC power source and turn on the subwoofers and your AV receiver. Most powered subwoofers come with volume and other controls located on the rear panel near the power switch. Play your favorite piece of music or video and make appropriate adjustments. If you feel the need to use a sound meter to check the low end bass intensity of your subwoofers, inexpensive apps are available that can turn your smartphone into an adequate – if not terribly accurate – sound meter. Decibel levels in the 50Hz to 200Hz range should be nearly equal from all directions.
- If the distance from your AV receiver to the subwoofers is more than a dozen feet, consult with your audio-video retailer for the correct gauge of shielded cabling. Use heavy gauge insulated wiring to reduce line loss, which is especially prevalent at the lower frequencies reproduced by subwoofers. Gold anodized RCA phono plugs can also make a difference in the quality of 50 to 200Hz sound reproduction. Move the subwoofers around to experiment with sound reproduction quality.
- Never point the subwoofer speaker cones directly at each other, which can cause signal cancellation, and never raise the subwoofers above the floor level, which can result in signal loss. Attempting to use unpowered subwoofers is not recommended, as they drain too much power from the AV receiver to be useful.
- Shielded cable
- RCA connectors
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