Choosing Home Audio Speakers
Why Do I Need All Those Speakers?
Art imitates life. In the real world, we don’t just hear sounds in front of us, but from the back and sides as well. In their attempts to make movies as lifelike as possible, directors duplicate this experience by sending certain sounds to the sides and rear of the audience. For these reasons, modern soundtracks include additional channels that surround audiences with sound. When movies are auditioned through a multi speaker theater array, viewers are placed in the center of the action. That’s why you need all those speakers!
Take a Balanced Approach
Your stereo, center, and surround speakers shouldn’t just sound good, they should all sound the same. Using a technique known as timbre-matching, top manufacturers achieve a consistent character of sound, or timbre, from main to center to surround models, assuring a seamless blend among all channels. Choose a brand that offers a wide range of timbre-matched models. Look at the drivers and tweeters used throughout the system. The tweeters should be the same. The midrange driver cones should be made of the same material, or better yet, the drivers themselves should be identical.
A chain is only as strong as the weakest link. This is as true in home theater systems as it is in many other things. With today’s home theater systems, every speaker in the system has a vital job and must do it well. When selecting home theater speaker components, strive for balanced performance. It makes no sense to overspend on one speaker component and skimp on others.
A description of each speaker in a home theater system, its purpose and how to choose the right one for your style, appears below.
The Stereo Pair (Polk RTiA9)
In addition to playing music, the left and right main channels of a soundtrack carry most of a motion picture’s special effects and orchestral score. In order to excel at these tasks, the stereo pair must encompass wide frequency and broad volume swings (dynamic range), reproduce subtle recorded details, and be able to create a convincing soundstage (the impression of three dimensions).
When choosing main channel loudspeakers, play a handful of music and movie selections you know well. Listen to a solo vocalist:. Does the image of that performer seem to float at the center of the soundstage (good), or can you trace the singer to the speakers (bad)? Next, try an acoustic guitar, violin or cello. You should hear natural, detailed string tone, as well as the resonance of the instrument’s wooden body. Finish with an action flick. Are the effects, gunshots, and explosions clearly reproduced, or do they become hard, flat and generally unpleasant as the volume increases? A good pair of loudspeakers should NEVER sound fatiguing.
The Center Channel Speaker (Polk CSiA6)
Although the main purpose of a center speaker is to fix the actors’ voices to the screen for off-center listeners, this channel also carries a good deal of the movie’s special effects. In fact, more than 50% of a typical film’s sound is routed to the center, and the speaker must be able to produce very high volumes without distortion or strain. So don’t skimp! Audition a scene in which several actors speak. Is each voice unique and articulate? Male vocals should be deep, but never boomy or chesty (emphasizing the deep chest sounds in spoken or singing voice). Higher pitched women’s voices shouldn’t sound shrill, spitty, or nasal. Finally, try a scene in which special effects pan from left to right; a car chase is ideal. Does the sound remain consistent, or does it become weak or lightweight as it passes through the center?
For a single listener sitting in the sweet spot (equidistant from both speakers), a center channel speaker is sometimes not even necessary. Simply engage the phantom center control on your processor or receiver, and you’ll hear a clearly localized central image. Of course, if you’d like to share the fun with friends or family, a good center channel speaker is a necessity.
Do you need a center channel speaker with good bass performance? For most systems, the answer is no. All surround receivers and processors have bass management for the center speaker. They allow you to direct the center channel bass information into the main or subwoofer channels. Your processor’s instruction manual will show you how to do it. The center speaker needs to reproduce sounds only from 100 Hz and up.
If you want the ultimate home theater performance, there are a few center speakers that can reproduce bass with authority, including a couple that even have built-in powered subwoofers. If your main speakers are ultra-high performance, you’ll appreciate the added dynamic range, kick, and imaging precision that a full range center speaker brings to the party.
The Surround Speakers (Polk F/XiA6)
The next time you’re in a movie theater, look around. See all those speakers lining the side and rear walls? They help the soundtrack encircle the audience. It’s this surround effect that places viewers in the center of the action. Since it’s impractical for homeowners to install multiple pairs of effects channel loudspeakers, manufacturers offer bi-directional (bipole or dipole) speakers, which place drivers on both the front and rear of the cabinet. This arrangement spreads the sound along the side walls, making it harder for the audience to identify the location of the surround speakers and delivering a more enveloping experience. This is especially important if the surround speakers need to be placed within a few feet of your listening position.
But bi-directional surrounds are not for everyone. With 5.1 channel systems, your rear speakers need to reproduce the same high frequency range as your front speakers and bass as low as 80 Hz, minimum. You’ll probably be happier with high performance front firing speakers than with a pair of cheap or mediocre bipoles or dipoles. Frankly, bi-directional speakers selling for less than $400/pair are not a wise choice.
To choose the surround speakers that are best for you, first select a location and the type of speakers (floor, on-wall, in-wall, etc.) that fit well in your room.
If you have or are planning on getting a Dolby Digital decoding system, select surround speakers that are as close as possible in performance to your front speakers. Look for the same or similar driver and tweeters as your front speakers. Pick speakers made by the same manufacturer as your main speakers.
In-wall or in-ceiling speakers are an attractive option for surround channel use. They can offer high performance and take up no space at all.
The Subwoofer (Polk DSWPRO600)
As we said before, a powered subwoofer is a speaker that reproduces only the lowest (bass) frequencies to provide a more exciting and lifelike movie experience. Since it has its own built-in amplifier, you don’t need to be concerned about whether your receiver or amp has enough power to drive a powered subwoofer.
A highly recommended option for stereo listening, subwoofers are an essential component of 5.1 channel digital systems since these formats assign additional low frequency effects to a separate subwoofer track. If you’ve chosen powered towers for your stereo pair, their built-in subs may make this sixth speaker unnecessary. If you’re looking to assemble a truly outrageous home theater system, adding a separate subwoofer to a set of powered towers will deliver an effortless, body moving experience.
There are a few things to keep in mind when selecting a powered subwoofer for your system. First, select a location for your subwoofer and measure the space to see what fits. Subwoofers generally perform best when placed near walls.
Next, the better your front main speakers, the better the subwoofer needs to be. If you have floorstanding speakers that already have good bass, select a subwoofer that is capable of reproducing very low frequencies so that it produces the bass that your main speakers cannot reproduce efficiently. A small, inexpensive subwoofer added to a pair of large, high quality floorstanding speakers may do more harm than good.
The size of your room is also a factor. The bigger the room you want to fill, the better the subwoofer you’ll need. Any open areas such as high ceilings or open walls are all seen by the subwoofer, even if you don’t listen in that area. Any airspace above suspended ceilings is also included. Thus the larger the room, the more powerful subwoofer you need.
What material is to be played through the system? Action/adventure movies have significantly more bass requirements then talk shows, news or comedies.
Ultimately how much bass you’re looking for in the system. If you want to rattle the walls and feel chest collapsing bass, one or more powerful subwoofers is recommended.
But the best advice of all is to ignore the numbers and simply listen before you buy. Many people get hung up on inches and watts. They assume that the bigger the driver size and the higher the power amp rating, the better the subwoofer. This is simply not so. Bigger doesn’t necessarily make better.
Here is where CEA2010 numbers come into play by giving real world acoustic output, or a loud and low rating instead of inches and watts.
Your dealer can let you listen to different subwoofers before you buy. If possible, listen with the front speakers you own or intend to get. Does the subwoofer add a deep bass foundation, or does it just boom? Listen with music as well as movie sources. Is the subwoofer tight and well defined with music, or does it just add a vague rumble? Trust your ears. Just keep in mind the dealer showroom acoustics can differ significantly then your home.
Tire Kicking - How to Judge a Quality Speaker
Although listening is the ultimate test of a loudspeaker, there are other clues to quality. Rap your knuckles on the sides of the cabinet: a hollow thud indicates a poorly made enclosure that will probably degrade the sound. The weight of a speaker will give you a clue as to the materials and construction quality. The best speakers have 5-way binding posts that offer the best possible connection with any type of cable.
Read the manufacturer’s specifications to make sure your amplifier and speakers will work properly together. The efficiency (a.k.a. sensitivity) rating tells you how much sound a speaker will produce when fed one watt of power. Choose a model rated at 86 dB or higher-a low-powered system needs high efficiency speakers. Finally, check the “impedance” specification. If you’ve chosen an inexpensive receiver, your speakers’ impedance should be at least 4-Ohms, and preferably 6-Ohms or higher.
This article was last modified Dec 4, 2013