|Buying a New Home With A Good Sounding Media Room|
|Home Theater Feature Articles Audio Related Articles|
|Written by Bob Hodas|
|Sunday, 01 August 2004|
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There is not much you can do about wall construction unless you decide to tear off the existing drywall (not a bad idea and not as expensive as you might think). If possible, look for minimum 16-inch stud spacing, not 24-inch. If you’re stuck with 24-inch spacing, add extra studs to stiffen the wall. Most houses are going to be built with sheetrock. Some basic isolation can be added to the walls and ceiling simply by adding another layer of mass. If you’re going to go to this amount of trouble, instead of using 5/8” sheetrock, go for some MDF or Wonderboard. These materials have much more mass than sheetrock. Be sure when you install an extra layer that it is glued and screwed and that the new seams do not overlay the existing seams. If you can afford it, there is a new material on the market that has a significantly increased amount of isolation. It is called QuietRock and QuietWood and you can get more information about it at here. I recommend it and you may find that you will simplify the construction process with this material. Any of these wallboards can be made more effective by floating them on resilient channel. This creates an insulating air space and isolates the new wall movement from the existing wall, very effective and of course more labor and money. There are various forms of this channel, so shop around. Here are some links to get you started: Silent Source or Kinetics Noise or Auralex.
For that matter, putting the audio room in a basement will solve some issues with wall stiffness as well as isolation. You might have to deal with venting of radon gas (because it causes cancer) and other less harmful but truly smelly elements from a basement. A dedicated small HVAC system can be a great addition to a dedicated theater room. The newest AC units can get your room cool much more quietly than units from even five or 10 years ago. When you are paying a premium for the most resolute audio gear with the lowest signal to noise ratio, it is a shame to waste some of the advantages in a room with a lot of noise.
If you are lucky, you might find a room that has wood on the walls. I’m not talking about that fake plastic wood panel crap, I mean real wood. Wood has a rich sound all its own. It tames the high frequencies just a bit and, to me, creates a very smooth, natural sound. On the opposite side of the spectrum, walls made of windows are very difficult to tame. Hard plaster walls can be tough, too (see below). Using thick drapes or fabric can help soften the blow of hard surfaces but when looking for a “perfect” room, do what you can to say no to that “Miami Vice” house built in 1986 with all the glass brick.
In a perfect world, you want as few windows as possible. This will be especially true if you are going to put in a projector and need the room dark. Of course, there are also isolation issues with the neighbors to consider. A house that has new, double pane windows is a perk because it can keep out noise from the outside world, as well as help keep the room more moderate in terms of temperature. If you live in a setting like Manhattan, you might need to really look at installing serious window solutions in order to get your room quiet. I recommend finding a window professional for advice in your area, since the solutions we use in studios are very expensive and typically custom-built.
Think about a windows contribution to overall reverb time. If you do have a big window like I have at my house (Sound Tips 4), hopefully it’s on the front or back wall and not on the side. Sidewall windows can be problematic for reflections and therefore for imaging. A window in the front offers the possibility of allowing some of the speaker’s rear-firing low-frequency energy to pass out of the house, thus eliminating loading and out of phase reflective energy at the listening position. Speakers designed to be flat in free space work well in this situation.
On the cheap, you can do several things. Replace your interior door with a solid core exterior door. Make sure you address the air spaces around the doors with some type of insulation as well. Remember that any little air space will leak sound like a sieve. Understand that this applies to your HVAC ducts as well, but this is something most home music room budgets can’t deal with. If you have more money, you can find some medium-priced, mid-quality doors being used in home theaters like those at Owens Corning.
If you have the space, a method used in recording studios that really helps with noise isolation is using two doors with an air space between them. While commercial recording studio doors are utilitarian in design, there is no reason why you can’t design the two-door system into a more ornate entry-way that is themed or designed to match your theater or music room. The effect of these doors can be impressive and I would never expect to find them already in a home. But you might keep an eye out to see if you could retrofit them to a house you were considering investing in.