You've purchased the best speakers you can afford, a great surround sound receiver, and a powerhouse subwoofer that's positioned as perfectly as it can be. And yet something doesn't sound right. Dialogue is muffled and unintelligible. Bass is weak or boomy. Music is lifeless or cacophonous. You find yourself constantly grabbing your remote to crank up the volume during talky bits of movies, and dial it way back when the action kicks in.
What many people don't realize is that by far the most important component of any sound system is the room itself. And even the best automatic room correction software can only go so far in dealing with the problems caused by poor room acoustics.
In fact, it can't do anything at all about one of the most egregious problems in many rooms: ambient noise. The hiss and hum of noisy return air vents can rob home theater systems of more fidelity than you might realize.
A far bigger culprit in sloppy sound situations is the walls themselves, though. If your room contains many hard, acoustically reflective surfaces, the sound from any given speaker is going to reverberate around the room before and after you you're supposed to hear it. To combat this, you'll need to treat at least 25% of the room with acoustically absorptive materials, which can range from thick draperies to purpose-built acoustical panels.
The key areas to focus on are what are known as the first and second reflection points along the side walls. You can find these by sitting in your main listening position while a helper slides a mirror down the wall. When you see the front speaker closest to the wall in the mirror, that's your first reflection. When you see the front speaker farthest from that wall, that's your second reflection. Adding absorptive materials to the walls at these points can have a huge impact on the imaging and clarity of your system.
You may also want to add diffusive materials at the rear of the room to break up large acoustically reflective surfaces. Diffusion is different from absorption in that it doesn't soak up sound, but rather distributes reflections more evenly, eliminating harsh echoes.
The key in all of this, though, is not to overdo it. A dead, lifeless room is just as detrimental to good sound as a harsh, reverberating one. A CEDIA home technology professional will not only know how much acoustical treatment your room needs, but can also recommend a variety of acoustical treatments, along with bass traps that tame the low frequency response of a room if proper subwoofer placement isn't doing the trick. These treatments can range from practically invisible solutions to panels that can be decorated with your favorite artwork, on up to elaborate pieces that in and of themselves resemble abstract sculptures, depending on your budget and aesthetic tastes.