Picking the right speaker layout for your room is the first key consideration when planning your surround sound system. Ever since the advent of digital surround sound, the total possible number of speakers for a given setup seems to keep rising. Do more speakers equate to more of an experience? Does adding additional speakers to a sound system add more realism? Are home electronics companies just trying to sell me more speakers and bigger amplifiers? Luckily, choosing the right configuration isn’t too difficult. The key is in considering the size and layout of your room.
Most of the soundtracks available on today’s DVD and Bluray movies are recorded in either 5.1 or 7.1 formats. This means that in a digital 5.1 recording, there are 6 individual (or discrete) channels of sound information. These include the front left, center, front right, surround left, surround right, and LFE (low frequency effects) channels. A 7.1 recording adds an additional pair of discrete surround channels, known as the surround back channels.
In an ideal situation, we’d have one speaker for every channel of information recorded on the disc. That being said, many rooms just don’t justify having that many speakers, either due to the size of the room, or the layout. Luckily, today’s A/V receivers are “smart” enough that we can tell them that we don’t have that many speakers, and it will mix in the missing information and play it through the speakers we do have. The most common example of this is when playing a movie recorded in 7.1 on a 5.1 system, it mixes in the missing surround back information into the appropriate surround channels.
The most common configuration for the average family room surround sound system is 5.1. Take a look at this layout of my guest room. It’s very small, but like most rooms in my house, I’d like to make it into my own personal theater area. The speakers are indicated in red. The left and right speakers are placed to either side of the TV, no farther apart from each other than they are from my seat on the couch. The center channel speaker is positioned directly beneath the TV. You can also locate this speaker above the TV but it should remain as close to the height of the left and right speakers as possible. The center speaker will play pretty much everything that’s happening on-screen, and serves to anchor those sounds to the screen for those who aren’t sitting directly in front (it’s for the guests and the in-laws). That’s not much of an issue in this room but is necessary in most situations – pay attention to this on the other diagrams.
Notice that the couch is all the way against the back wall. This is obviously because of the very small size of the room. Typically, this is a bad place to sit for acoustic reasons but where else would I put the couch in this tiny room? In any layout like this where the main seating location is against the wall, it’s an automatic indication that you should do a 5.1 configuration. Adding additional rear speakers over your head or in the wall behind you shooting out over your head will not provide any real benefits for your movie watching experience. To do anything greater than 5.1 you have to have space behind the seating location.
It’s also important that none of the rear speakers are too close to the seating location. If a speaker is right in someone’s ear for the whole movie, they’re not going to watch movies with you anymore. In this setup, choosing in-ceiling speakers for the surround channels helps me get the speakers at an acceptable distance from the seating location, while still aiming them in my general direction. In this case it also helps me to avoid the in-swinging door into the room.
Placement of a subwoofer is a bit more flexible than the other speakers, because the low bass it plays is typically so low that our ears can’t tell where the sound is coming from. That being said, we’d like to try to keep it at a similar distance away from all the seating locations, so that we can keep it in good balance with the rest of the system. Also, if it’s too close to a someone’s seat, they’ll be able to localize the sub not by hearing it, but by feeling it. For example, if I put the sub where the plant is next to the couch, the person in the left seat is going to get way more bass than the person on the right, and they’ll also be able to feel where the bass is coming from, thereby localizing the sub. Also, the smaller the speakers used for the front channels, the more important it becomes to place the subwoofer up front with them. This is because small speakers can’t play the lower-mid and bass frequencies as well as larger speakers, and so we have to ask the subwoofer to play some of the higher bass to fill in – this is when we can start to localize the sound coming from the sub. Bose owners know what this is like… those poor, poor souls.
Corner oriented rooms are often perfect for a 6.1 configuration. In all of the configurations, the things previously discussed regarding the front three channels and the subwoofer all apply. The major difference is in the layout and number of the surround speakers.
Consider this layout in the family room of my parents’ house. The TV and front speakers are all in the corner, with the seating arranged around the walls. Plenty of people can sit in here and enjoy a movie or a football game, but placement of the surround speakers is a little weird. How would this look if we were only doing a 5.1 system (one pair of surrounds)? Notice the position in the diagram of the surround left and surround right. The main viewing locations in this room are in the corner opposite the TV on the couch and loveseat. Drawing an imaginary line between the SL and SR speakers we can see that they are in front of those seating locations. Not much of a surround sound experience there huh? This can be solved by upgrading to a 6.1 configuration, which adds a third surround speaker called a surround back. Note its location in the diagram. This third rear speaker provides an enveloping experience for the best seats in the room. Now everybody gets good sound – except for the chair, we don’t really care about that spot. The person that sits there is a fat guy that falls asleep all the time anyways. In some situations you have to recognize the seats used most often, and optimize the experience for those seats.
With a larger room and space behind the main seating location, it’s possible to do a 7.1 system. This setup provides the most seamless and enveloping surround field, especially for a larger audience. The surround left and right channels effectively become surround sides, while an additional pair of rear speakers serve as surround back left and right channels. In the example in the diagram in-wall speakers are used instead of in-ceiling.
Recently some receiver manufacturers have been including even more channels of information for surround sound receivers. On many models today, you’ll see the possibility for 9.2 or even 11.2 setups. The extra pair of channels in a 9.2 configuration are for either front height or front width channels, and are supposed to provide a bigger sound-stage up front. The 11.2 configuration goes even further by adding an extra pair of rear height channels. The .2 simply refers to an extra subwoofer hookup. These expanded configurations haven’t really caught on yet, since no movies exist with recordings greater than 7.1. In the case of these receivers, they take the 7.1 recording and make the extra channels by taking pieces of the other channels to play through the additional speakers. A properly designed and setup system will be able to reproduce a sense of great height and width anyways, so these additional speakers aren’t really necessary for most home theaters. These additional channels can be used to power speakers in other rooms, however, which is particularly useful for listening to music.
Choosing the right surround sound configuration for a family room can seem overwhelming sometimes because it seems that everyone’s room is different. By following some of these basic principles, you should be able to figure out the right configuration for your room. Feel free to comment below if you have questions or can add to the topic, or email me at email@example.com.