The subwoofer is a vital element in good home theater sound, because aside from the obvious dynamic benefits it can impart, a sub can also open up the midrange, contribute to musical bass lines and even drive the room’s acoustics more effectively. However, a bad subwoofer will do more harm than good, by slowing the balance down, softening the system’s attack and generally making a sonic nuisance of itself. In our view, you’re better off having no subwoofer at all, than opting for a compromised design.
Once you’ve specified a sub, the next stage is to integrate it into the system. One school of thought holds that subwoofers can be positioned anywhere in your room, as bass is ‘non-directional’, but we’d disagree. A spot of fine-tuning can notably improve your system’s speed and integration, both with movies and music.
Here’s how. Put your subwoofer next to where you normally sit. Disconnect the speakers (at the amplifier/reciever end), but leave the subwoofer connected. Play a loud piece of music, with a consistent bass beat. Walk around the room, listening to the bass as you walk. You’ll find it sounds louder in perhaps two or three places in the room (usually the corners). Put the subwoofer in one of these positions, which are referred to as ‘nodes’. If this turns out to be behind you rather than in front of you, you may need to reverse the sub’s phase, using a switch fitted to its amplifier control panel.