Keep
in mind that bass quantity does not necessarily equal quality, though. This can
be particularly important if you’re dealing with a subwoofer. All rooms have
resonant peaks based on the distance between room boundaries. A complete
discussion of the interaction between loudspeakers and room resonant modes is
far beyond the scope of this article. Check out books like F. Alton Everest’s Master Handbook of Acoustics, or my own
Secrets of Home Theater. It never
hurts to experiment, though. Just make sure you rebalance the subwoofer’s level
using the tips in step 4, before you listen to the system to see if there’s been
an improvement in quality, and not just quantity.
You
should also try to move the speakers so that they’re not equidistant from
various room boundaries. If the left speaker is two feet from the side wall, try
to make sure that the speaker is not two feet from the wall behind it and two
feet from the floor (or ceiling), as well. Satellite speakers, which play
midrange and treble frequencies, often sound best when placed a few feet out
from the wall. No matter how far the speaker is from a room boundary, the
distance between you, the speaker and any particular boundary will cause certain
frequencies to cancel out to some extent thus degrading sound quality. The more
varied the distance to each boundary, the more varied the frequencies affected
and the more natural the speakers response will be.
9.
Add
acoustic treatments or move furnishings to reduce unwanted room reverberations.
This
gets close to the boundaries of our self-imposed “no replacing equipment” edict,
but falls short since you can accommodate many of the ideas through creative use
of existing furnishings. Sound coming from your speakers emanates in multiple
directions at the same time. The sound that travels directly to your ears
arrives prior to the sound that travels in a different direction, reflecting off
of nearby surfaces before reaching your ear. If the reflected sounds arrive too
soon after the initial, or direct sound, bad things happen that will degrade
sound quality. (Yeah, Okay, so I’m generalizing a bit. Just go with me here.) If
you can eliminate some of these early reflections, you can improve the clarity
and quality of the sound.
Doing
so requires that you either place acoustic treatments (thick foam or
fabric-covered fiberglass absorbers and hard, varied multi-level, 3-dimensional
checkerboard-like diffusers) or sonically equivalent household furnishings
(heavy drapes and bookcases) at the early reflection points. You can find these
points by imagining that the walls of your room are mirrored (or just have a
friend slide a mirror across the wall). In the places where you see reflections
of your speakers, you’ll want to add acoustic treatments. You shouldn’t only use
absorbers or the room will sound somewhat dead and lifeless. Keep an even mix of
absorption and diffusion.
