Build Your Home Theater – Room Dimensions
Why do you need to pay attention to the “room dimensions” of your new theater? It comes from the fact that sound travels through air as waves, and those waves will tend to behave differently based on how much air is present in a room. The amount of air in a room is calculated directly from the length, width, and height of your room.
Simply stated, a speaker creates “sound” by pushing a wave of air towards the listener (think of an ocean wave). Now, if this wave comes from the front of the room, it will eventually hit the rear wall and reflect back to the front, eventually hitting the next wave of sound traveling towards it. Depending where that reflected wave hits the new oncoming wave, and the frequencies involved, you can experience a phenomenon of either a multiplication of the merged wave (the sound gets louder), or the two waves will cancel each other out (the sound gets quieter). This will cause some seats in your theater to hear too much bass from that explosion, and others to hear too little.
Take the above example and add in the waves that are reflecting off the side walls and ceiling… all these waves hitting each other… frequencies merging… now you can see why we should look at what we can do to limit these clashing of these waves.
Here are things to consider when deciding on your dimensions:
Avoid square rooms. Square rooms will screw around with your bass… bigtime. You will get some areas of extreme bass, and other areas of inaudible bass.
Make sure the dimensions (length, width, height) are not divisible by a common denominator… for example, do not use 36x24x8 because each dimension is divisible by 4. Instead use 35x21x8. This will help to minimize clashing frequencies.
Do not build a huge room… keep the room dimensions on the practical side. The bigger the room, the bigger the speakers will get, and you guessed it, the bigger the amplifiers will get.
Figure out how many seats you want to have in your theater, and make sure your dimensions can accommodate them. Now be realistic… if you hardly have company over, building a theater that accommodates 16 people is just a lot of extra work.
You will need to look at your equipment and see how big that HDTV is. Check a viewing distance chart to see what the minimum viewing distance is to get a good picture. The room will have to be at least this long. With these new HDTVs, it is getting easier to seat people closer to the front of your theater because the quality of the picture is better.
If you follow these simple steps, you will be able to modify your room dimensions accordingly before you start construction.