It’s Friday and time for our once per week shoot-the-shit. Regular readers know that shoot-the-shits have no rules – you can use profanity, put forth unsupported ideas, falsehoods, change the subject or disparage someone you dislike, it’s truly limitless. With that introduction out of the way, let’s talk home theater system.
What is the most important component in a home theater system? It’s not the screen, the speakers or amplification. It’s the room! I have seen home theater systems with $100,000 per pair speakers from Wilson and $12,000 amplifiers (that’s each) sound like crap. Generally these installation were designed by interior designers with no understanding of acoustics. So let’s talk about rooms.
Bass frequencies in the range of 20Hz to 100Hz love to pile up at wall-wall intersections, ceiling-wall and wall-floor; they are also non-directional. A well balanced subwoofer, meaning its output is matched to the room size and acoustics, is not audible; it’s felt. High frequencies, >100 Hz to 20,000 Hz, are like bullet ricochets; they bounce around. To reduce or eliminate those reflections we dampen them using a variety of wall treatments. You can test your planned home theater area by standing where you plan your seating and loudly clap your hands. If you hear ringing or reverberation you’ll want to dampen the walls, floors and ceiling.
Ideal home theater areas will have a cathedral style ceiling, tightly knit floor covering not unlike what you find in a theater and no parallel walls, if at all possible. If you have a new construction project have the developer add a second sheet of sheetrock to each of the room wall. Avoid home theater spaces with a lot of glass.
Lets talk about wall treatments and dealing with bass, I’ll start with bass. Wall and ceiling intersections are 90 degrees, you need to eliminate that angle and add some absorption. Take a look at the bass trap below…
You can easily build this at home and cover it with a nice fabric. The important point is that you break up the 90 degree interface. I would use some plywood, acoustic foam but do a nice job upholstering it.
To eliminate high frequency nastiness, build a large picture frame with a backing, use something like .25” plywood or particle board for the backing then pack and staple fiberglass insulation, 2 or 3 layers if possible on to the frame. Pick out some nice fabric with not too tight of a weave and upholster it.
It will look something like this… 
There is a right way and wrong way of using panels; I’ll provide you with the inexpensive secret. Start by placing a mirror against the side wall and about 3 feet in front of your main speakers. Next, sit at your sitting position and desired seating height but look towards the mirror. If you can see any part of the speaker, mark that spot for a panel. Keep shifting the mirror’s position along the wall until you can no longer see the speaker; marking each one of those points for panel installations. The size of the panels should be as shown on the picture but you could also have one large panel although I don’t recommend it. Involve your spouse in the fabric selection and upholstering piece, if you want to same your marriage.
By working on your room, you will derive maximum benefit from any equipment selection that you make. If you’re at the top of the socioeconomic pecking order and can afford $30,000 in room treatments, make sure that you are dealing with someone that will sweep your room and knows what they’re doing. What I’ve suggested here will run you about $500 if you do the work which is not hard at all and it’ll look like a million bucks. I promise.
FOG HORN 