My system was designed and installed as part of a major home remodel. This provided a major advantage in that I was able to use built in speakers all the way around. The look is much nicer than having boxes sitting on the floor or hanging off the walls. Speakers are one case where one size does not fit all, even within a single installation. The front, surround, and subwoofer speakers all have different functions and requirements. Once you have your speakers where you place them is also important or the sound won't be accurate as to what the program intended.
The front speakers are where most of your sound will come from. You will want to spend more for the highest quality on these speakers. This is also one case where looks may matter because these speakers will be in your field of view while watching the television. You will want good multi-element (the number of little speakers in the enclosure) speakers with a wide range and the ability to handle the amount of power being provided by your receiver.
For my installation I went with the Polk TC265i speakers for the front (left & right) and center speakers. These are big three element speakers that can take 200 Watts of power. The speakers are 20.6" x 8.5" but only 3.5" deep so that they can fit in standard wall openings. Being designed for installation in the wall these speakers do not require a box enclosure but actually recommend packing insulation in the wall opening before putting the speaker in. This will help to eliminate any stray vibration in the walls.
When these speakers are mounted the best visual effect is achieved by oreinting the left and right front channel speakers vertically and the center channel speaker horizontally (either above or below the television screen). Being that the speaker is over 20" long, it won't fit between standard wall studs (16" on center) when horizontal. If the walls are open (during new construction or a major remodel) this is not a problem. For a non load bearing wall it is within code to cut out a section of a wall stud and then run a horizontal piece between uncut studs to secure the top and bottom of the cut stud. If working with a load bearing wall it will be necessary to from the opening as if it was a small window with proper headers and supports going to the floor. If in doubt consult with a licensed professional.
The surround (side) and back speakers are what give your home theater a sense of depth. A 7.1 system requires four speakers to create the full surround field. The speakers should be above ear level so ceiling mounting is a very good solution. While rectangular speakers usually look better in walls, round speakers are considered more appealing for the ceiling.
I went with the Polk RC60i speakers for my surround and back speakers. These are 6-1/2", 2-element, round speakers which practially disappear in the ceiling. These speakers are rated for up to 100W, which is right about the power rating put out by most receivers. Also, the small tweeter (high-frequency) elment can be angled slightly so you can direct the sound back towards your seating position instead of having them fire straight down.
The RC60i has an overall frequency response of 40Hz to 20kHz. For surround speakers this should be acceptable. If you want to get a slightly wider range you may want to consider the Polk RC80i. These are 8" speakers which have an overall frequency range of 35Hz to 20kHz, giving a little more deep tone at the bottom end of the spectrum.
The angle of your speakers is very important to getting the right sound effect. Dolby Labs has set the standard for proper speaker placement in a 7.1 layout. In the table below the angle is measured from the point looking straight ahead. 0° is forward, 90° is to the side, and 180° is directly behind.
|Speaker||Min Angle||Max Angle|
|Front (L & R)||22°||30°|
|Surround (L & R)||90°||110°|
|Back (L & R)||135°||150°|
Distance is not as important. In an ideal situation all the speakers would be the exact same distance from your ears so that the sound reaches your listening point from all speakers at the same time. Being that most home theater rooms are not shaped like a sphere, this is not going to be the case. Fortunately, most receivers compensate for this by allowing you to set a delay in each speaker to adjust for differences in distance. Even better, many mid to high range receivers can auto adjust the delay using a microphone which comes with the unit. All you do is setup the mircophone, go to the right place in the menu, and then cover your ears as a loud sound comes out of each speaker which the microphone measures for delay.
If you do an in-wall and ceiling installation of your speakers be careful of the type of speaker wire you use! This is a mistake I made which ended up costing time and materials. The clear jacket speaker wire commonly used to run to floor standing speakers is not allowed for in-wall installation. The wire you buy should specifically list in-wall installation.
Another import factor in the speaker wire is the gauge. The heavery the gauge (lower the number) the better you are. Heavier wire has lower electrical loss and can carry more power. Speaker wire is commonly found in 12, 14, and 16 gauge. 16 gauge is very thin and should only be used for short runs. 12 gauge is necessary if you are doing extremely long runs, such as to remote speakers outside. For a typical home theater environment, 14 gauge wire should be thick enough to handle the distance to carry and the power needed.
Finally, make sure you buy enough. My setup with seven regular speakers and two subwoofers required almost 300' of wire. There is a lot more distance to cover when the wire has to go up, across, and maybe back down walls and ceiling.
You will need a way to get from the speaker wire in the wall back to your receiver. Having a professional looking system just doesn't work if you have bare wire coming out of a hole in the wall. The way you handle this transition is with a wall plate. If you bring all of the speaker wires into a double size electrical box you can finish off the wires with a pre-built 7.1 binding post plate. Locate your terminating point behind your home theater and then use short speaker wire leads with banana plugs to finish the connection.
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