HOW TO... Set up your subwoofer
Set up a subwoofer correctly and it'll make a big difference to your system's sound. The only problem is, many people don't know where to start with sub setup, and as a result get it very wrong indeed. In fact, we'd say if there's one factor that most commonly lets an otherwise great system down, it's the relationship between the subwoofer and the rest of the speakers. But don't worry: we're here to take you through our tips for achieving beautiful bass.
For starters, deep bass is less directional than treble or midrange, so you can put your sub almost anywhere. However, you can get better results if you do some fine tuning – and here's how.
For the best integration with your room, try to find a room 'node'. Place your subwoofer where you usually sit, connect it, and then disconnect your speakers (at the amp end). Play a piece of music with plenty of good bass, and then walk around your room, listening to the low frequencies.
You'll hear lifts in bass in several places, caused by the interaction of the bass notes and your room's acoustics. These are 'nodes', and your sub should go in one of these locations.
Don't, repeat don't, turn the volume up too much on your subwoofer. It's one of the most common failings we hear in systems. Bass should underpin your sound, contribute to it where appropriate, and on occasion, shake your sofa on its springs - but it isn't supposed to dominate the sound completely. Remember, whether you're watching Beyond Enemy Lines or listening to the latest Joanna Newsom album, realism is the greatest sonic virtue of all.
So, if there's no need for bass in a particular scene (say, a long sequence of dialogue) then there shouldn't be a peep out of the sub - so don't turn your subwoofer up so you can hear it all of the time. You're not meant to.
A lot of AV receivers don't include test-tone adjustments for sub-woofer levels - but even those that do suffer from the problem that most hand-held sound pressure meters struggle to register bass accurately.
The best way to set your sub levels is to play a piece of stereo music that you're familiar with: turn the subwoofer's volume level up until you can just hear the bass starting to dominate a little too much - and then drop the volume back a tad. This might not be a completely scientific method, but it works.
Get these simple steps right, and your sub will be everything it's meant to be: powerful when needed, room-shaking when desired, subtle when it's asked to be and silent when it should be.