How to Wire a Second Subwoofer to a Surround System
By David Lipscomb
In today's multichannel home theater setups, a subwoofer is essential in providing the low frequency impact demanded by modern movie and game soundtracks. However, it's not uncommon for peaks and nulls or dips in response to occur in certain parts of the room. Adding a second subwoofer typically alleviates this issue, providing more and smoother bass response.
Turn off your home theater receiver. Locate the "SUB" output on the back of the unit.
Unplug the existing RCA cable leading to the main subwoofer. Plug the single male RCA plug into the "SUB" jack on the receiver.
Insert the existing RCA cable and the one leading to your second sub into the two female outputs on the "Y" adapter.
Plug the RCA cable into the "LFE" or "IN" jack on the second subwoofer.
Plug both subwoofers into the closest available AC outlets.
Snip two lengths of speaker wire long enough to reach from the front speaker terminals on your receiver to the subwoofer's intended location. Strip 1/2 inch of insulation from both ends of each run.
Rotate the binding post terminals for the front or "Main" speaker wire terminals, until the holes on the binding posts are exposed. You are loosening four terminals in total, two red and two black.
Rotate the corresponding input binding posts on the second subwoofer. This may be labeled "Input," "High Level In" or "Speaker In." Insert the wires into the binding posts on the receiver and subwoofer, matching positive and negative polarity.
Tighten each binding post clockwise until each wire is secure. Make sure you don't see any stray wires on the receiver or subwoofer touching the chassis of either unit.
Cut another pair of speaker wires long enough to reach from the output binding post terminals on the passive subwoofer to each of the front main speakers. Strip 1/2 inch of insulation from both ends of each wire.
Loosen the output binding post terminals on the passive sub, labeled "Output," "To Speaker" or "Out."
Loosen the binding post terminals on each of the front speakers. Connect the left channel output on the subwoofer to the binding posts on the left speaker, careful to match polarity correctly. Rotate the posts clockwise on the sub and speaker. Repeat for the right output and speaker.
- Ensure the front speakers are set to "Large" in your receiver's settings or you won't get any bass from the subwoofer.
- Placing two subwoofers in opposite corners or ends of the room usually yields the smoothest response.
- Do not connect a passive subwoofer rated for less than 8 Ohms to any home theater receiver. Low impedance combined with deep bass will shut down most receivers, possibly causing damage if the fault is severe enough.
David Lipscomb is a professional writer and public relations practitioner. Lipscomb brings more than a decade of experience in the consumer electronics and advertising industries. Lipscomb holds a degree in public relations from Webster University.