Be an 'Ace of Bass' - Part 4
Over the last few weeks we’ve taken a look at the basics of sound and how bass interacts with the listening room. We’ve also explained how bass management works within an AV processor or receiver and the effect crossover frequency has on speaker setup. This week we get down to the practical “nitty gritty” of placing a sub woofer in a room…
Lets get this out of the way right from the off – there is no “golden bullet” when working out the best position for a sub. What you hear from a sub woofer depends on a whole host of factors, many of which are difficult to predict. The size and dimensions of the room, sub position, listening position and room construction all play a part in the resulting sound and mean absolute recommendations are impossible. However, there are a couple of things to try that often lead to good results.
No one puts baby in the corner! (But a sub might be just fine…)
As we know from part 2 of this series, boundary gain means that placing a sub woofer close to a wall or floor (or ceiling for that matter) will generate an increase in perceived loudness. Placing a sub in a corner delivers three surfaces that all add gain (the floor plus two walls). Because of this the corner is often a good place to put a sub and is probably the best “first guess” at a good location. Again, absolute dimensions of the room will dictate if the corner is the very best place but it’s a good starting point.
Time for a “Sub” crawl
Sub woofers are heavy things. Add the accompanying mains and signal cables and they are pretty cumbersome objects to be dragging round the room while trying to find a good spot. The good news is that the sub location and listening position can be swapped over and the same results achieved. So, if you place the sub at the listening position you can move yourself (and your ears…) around the room and get a feel for how a sub would sound in that position.
Disconnecting other speakers and using some material with strong bass content will help with this experiment. Listen out for a good, even bass where bass notes all have a definite sense of pitch and are of near equal volume. There will often be more than one good position leaving you to choose which is most “domestically acceptable”.
3D is not just for pictures
Whenever you consider bass do remember that sound is three-dimensional. The relative position of a sub (or listening position) to the floor and ceiling is just as important to the resulting sound as to the sidewalls. If you try the experiment described above the sub will need to be placed at the same level as your ears would be when listening.
That’s all for this week. Next week we wrap up this series of posts with a look at equalization.
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