By Eric Podolsky, 8/27/12
When building a home theater, there is no debate as to the importance of choosing an audio configuration that’s the best fit for your taste, as well as your space. Whether you’re looking to keep it minimal and compact, or want to go all out with big, floor-standing speakers, care needs to be given to their configuration if you want everything to sound its best. Here are some of the main considerations to take into play when choosing your home theater’s surround sound configuration.
As most AVS members will tell you, room dimensions should be considered first and foremost when choosing an audio setup. The size and shape of your room play the ultimate deciding factor in everything, including the number, size, and placement of your speakers and subwoofers. For example, AVS member arnyk explains why it’s important to match your subwoofer size to your room size: “Every room has a frequency below which response starts to ramp up. The larger the room, the lower the frequency...Take a really small room like the passenger compartment of a small car. The ramp up starts at a relatively high frequency, maybe as high as 100 Hz or more. If your audio system starts rolling off at 100 Hz, the ramp up combines with the roll off, and its a draw... If the ramp up/roll off points don't match, then you get a hole or a peak. Both are bad, but the hole is probably more tolerable for most people.... In a larger room the ramp up starts at a lower frequency, say 20 Hz. If your audio system starts rolling off at 50 Hz, then there is a hole in the overall response between 50 and 20 Hz. Not good.”
Room size is also essential when choosing the number of speakers you’ll be using for your system. While 5.1 is the standard-go-to for most, this is entirely customizable based on personal preference. Whether you go with 2.0, 2.1, 5.1, 7.1, 10.2, or any other conceivable configuration, be sure to take your space into consideration. For example, if you have a big room and are considering 7.1, make sure you have enough room behind your seat, as 7.1 surround speakers need space. AVS member C0rk points out that while “in a 5.1 system, the surround speakers go on the sides... [7.1 is] really more of whether you have room behind your listening area, not so much room size.” No matter what shape and size your room is, be assured that there is a sound system that fits it perfectly -- it just needs to be discovered.
One essential factor in choosing the speakers you install is what you’ll be using them for. Your ideal setup will vary depending on whether you’re using your system for TV/movies, gaming or music -- each activity demands something different from a system. 5.1 is the default for most who use their system for TV/movies, though more and more folks are going with 7.1 as of late. But before you splurge on a big 7.1 system, keep in mind that it may be overkill. AVS member Jay1 says that 7.1 “is only needed for theater seating type situations,” and WagBoss agrees: “7.1 is pointless unless you have a large home theatre. You can't run 7 speakers off an AVR very well without external amplification.” Video games typically demand similar requirements from systems as TV/movies do, although there is often more of an emphasis on the low-end -- there’s nothing like a good responsive subwoofer rumble when you’re deep into a first person shooter.
If you use your setup mainly for audio, a 5.1 system will probably get less use, as there’s only a relatively small percentage of music that is mixed for 5.1 surround. It is more than worth it though, if you have access to those high-fidelity recordings that are compatible with 5.1. Other audiophiles prefer two floor-standing speakers in front to maximize the fidelity of stereo recordings, and depending on their size and quality you may not even need a subwoofer -- many 2.0 floor-standers can provide a well-rounded sound with great low end. Member smasher50 suggests that if you’re using your speakers “strictly for music, I don't think you need a sub unless you listen to a lot of classical and pipe organ music, or if you are going to use it with TV/movies.” 2.0 floor-standers may not be the best value though, as member pureiso points out that “for the same price range you can generally get a much better bookshelf speaker.” But if you’re not worried about price, two floor-standing speakers may be your best option as a music-listener.
Picking Your Speakers
Once you’ve determined the number and size of your ideal speakers, it’s time to get specific and choose a brand and model. Unfortunately, this is one area where you are on your own -- with so many quality types on the market, we can’t in our right mind single out any specific speakers in a general guide such as this. For this task, AVS’ knowledgeable forum experts are happy to help with suggestions based on your specific room layout.
That being said, there are a few widely accepted rules for picking your speakers. WagBoss advises: “Generally, people say that the front three speakers should be the same brand and model line. All front speakers will have a matching center. Surrounds don't matter as much, unless you listen to SACDs or other multi-channel music. For subwoofers, it doesn't matter at all what brand.” Also be sure not to invest too heavily in areas that aren’t as essential, as steveklein suggests: “I think the fronts are significantly more important than the rears/surrounds. Several years ago, I spent about $500 a speaker on my fronts and about $150 a speaker on my surrounds and i've been very happy with the results...IMO, I think it is silly to spend the same amount of money on surrounds as your front soundstage.”
In regards to the floor-standing vs. bookshelf speaker argument, it’s all about personal preference, as each have their benefits. WagBoss mentions, “There's not much difference between floor standers and bookshelves if you have a subwoofer. Find ones you like, as it doesn't really matter if they are towers or bookshelf. Bookshelves are smaller, so they take up less space, but you have to mount them or get stands.” Again, it’s all about what works for you.
Now that you’ve made a well-informed purchase, it’s time to install. But take care -- speaker and subwoofer placement are essential to make the most of your system’s capabilities, as every room is different, and needs its own unique layout to optimize its sound. While ideal speaker and subwoofer placement will vary according to your room’s layout, Dolby has a helpful guide that gives a basic layout of where you should generally place your speakers, depending on configuration. Of course, there are many variables to consider (room shape and speaker size, to name a few) when deciding speaker placement, but most will agree on their ideal height, as AVS member jb82 explains: “The front tweeters should be at ear level... it's best to angle [the center speaker] up or down towards your ears if possible.” There is some more debate as to the height of the surround speakers, as many also suggest an ear level placement, though some say that 2-3 feet above ear level is optimal. If you’re using floor standers, there are other factors involved in placement, as member ack_bk points out: “Most floor standing speakers need a minimum of 12-24 inches from a boundary (side and back walls) to get proper imaging and sound.” If you’re working with a smaller room, smaller bookshelf speakers may be your best bet -- of course this will mean that you’ll need a dedicated subwoofer to make up for the low end that bookshelf speakers can’t deliver.
Ultimately, only you will be able to determine where to place your subwoofer to achieve the best acoustics for your surround sound system is experimentation with placement and orientation. Trial and error is a tried and true method, so experiment away, taking into consideration your room’s unique angles and contours. As member ccotenj attests, “as far as positioning goes... man, would life be a lot easier if there was a cut and dried answer to that question...” Which brings us to our next section...
This is an issue that everyone installing their own home theater has struggled with. In addition to speaker placement, there are other ways to optimize the rooms acoustic
s for the best sound possible. Customizing your system’s EQ to fit your space is one tedious-yet-rewarding way to make things sound great (this could take some time to perfect).
One essential addition that is guaranteed to help with this is the installation of bass traps in your room’s crevices, which catch sound waves so that they don’t overlap and cause muddiness. AVS member and bass trap expert Ethan Winer explains: “The cause [of nulls across the mid and upper bass range] is reflections off the walls, floor, and ceiling, combining with the direct sound from the speakers and with each other... You'll never get a perfectly flat response, so the more bass traps you have the closer you'll get. It's that simple.” dwightp agrees with Ethan’s argument for quantity: “Put in as many bass traps as you possibly can. Bass traps are generally most effective in corners -- wall-to-wall, wall-to-ceiling, wall-to-floor, etc.”
Construction of bass traps can be made from a variety of materials, as Ethan Winer lays out: “Traps can also be made from rigid insulation board, OC703 or the equivalent. You can cover the bass traps with acoustically transparent fabric, if you want.” Member FOH adds that “thick bass traps are best constructed out of cheap 'fluffy' style insulation. For attenuating reflection points for wall mounting, use 703 of 4" minimum, with a 4" gap.” Fill those corners right, and you should be basking in aural bliss in no time.
But there is one rule of thumb that applies above all else: always test speakers out first-hand before making a purchase. Better yet, make sure you have a good return policy, as the room in your home is guaranteed to sound different than a store’s showroom. Everybody’s ears are different, and you should ultimately rely on your own opinion at the end of the day, no matter how many recommendations are thrown your way. To each his own, and if you do your homework, you’ll be well on your way to an epic home theater experience. Happy hunting!