Good speakers are the key to getting the best possible audio experience from your sound system. You can put together the best CD or DVD player on the market and the highest-rated A/V receiver, but if you don't have the right speakers, your audio or home theater setup won't be worth much when it comes to actual sound. Your speakers provide the critical link between all the complicated things your audio system's internal components are doing, and physical world where you actually hear the sound being played. Choosing the right speaker for the job is important, and can make the difference between enduring a muddy, sonic terror or sinking into a lush, aural experience.
Overview--Dispelling Some Myths
So, how do you know which type of loudspeaker is appropriate for you? The "whys" and "hows" of the matter could fill a book, but one thing's for sure: there's a couple of misconceptions about loudspeakers we need to dispel first.
1) "Bigger is better." -- Big speakers don't necessarily play louder or sound "bigger" than small ones, nor do they necessarily have better-quality bass. In this case, "more" occasionally can, but does not always, equal "better." A three-way, or three-driver, speaker will not necessarily sound better than a two-way design. In fact, it is quite difficult to create a speaker with more than two drivers that is both affordable and provides high-quality sound. A twelve-inch woofer does not always produce better bass than a ten-inch one.
2) "More Watts equals more power." -- You may have seen ads for inexpensive "1000-Watt" speakers. Due to the host of ways companies can measure speaker power, this can be an all-but-meaningless specification, which we'll explain below.
It takes a lot more than raw technical specifications to determine what speaker is right for you. Amazon strives to give you all available information about the speakers that we carry, so you can be confident in your choice.
Before going further, it is important to understand a few of the terms and key concepts used when describing speakers and audio equipment.
1) Volume -- While volume is a concept that we are all familiar with, it is a critical factor in speaker choice. If you live in a dorm room or an apartment with thin walls, you may be playing your system at low levels much of the time. Some speakers sound surprisingly "alive" at low volume while others need to be played loud to get going. Some speakers start sounding hard, grainy and compressed at higher volumes. A well-designed speaker will sound good at both low and high volumes.
2) Frequency, Response and Balance -- Frequency is a measure of how high or low a sound is pitched. A speaker's frequency response is the measurement of how wide a selection of sounds it can reproduce. Can it satisfactorily reproduce low bass and high treble? This is one of the areas where specifications can help you out. Keep in mind, though, that very deep, high-quality bass is usually expensive. If you're on a budget and not after high-powered home-theatre performance, you might be more satisfied with good midrange performance since that's where most of the music is anyway. Extended high-frequency response is somewhat easier to achieve at reasonable cost, but watch out for "peaky," edgy, over-enhanced highs, which can grate on your ears after extended listening.
Speakers that are engineered with a wide frequency response are worth having, but usually not at the expense of frequency balance. This is an overall feel for how "neutral" it sounds. If the speaker overemphasises bass frequencies, then the sound will be mushy and the actual notes will be difficult to distinguish. If it accentuates the high frequencies too much, it may sound bright and harsh. On the other hand, if a speaker de-emphasises a frequency band, like the upper midrange, it will sound dry and lifeless. If it short-changes the midbass, it will likely sound thin and "sucked out."
3) Soundstaging -- Another important consideration is stereo imaging or "soundstaging", which is the ability of a speaker pair to create an adequate sense of width, depth and height. To appreciate a speaker's soundstaging ability, it's important to sit directly between the speakers and listen to a simply produced live or "acoustic" recording, rather than a large, artificial studio production. The human ear responds well to spatially correct "cues" in the form of subtle reflections from surfaces in the room where music is recorded. When these reflections are faithfully recorded and played back, the result can be a stunningly real sonic "portrait" of a musical event.
4) Wattage and Power Handling -- Wattage is a measurement of electrical power. When applied to speakers, it is the amount of power a particular speaker can take from the amplifier that is powering it. There are two types of wattage when it comes to speakers: "RMS" and "Peak Power." RMS is the amount of power that a speaker can constantly use to produce sound without incurring damage over long periods of time; because of this it is also called "continuous power." Peak Power is the amount of power the speaker can take for very brief explosive passages of sound or music. It behaves a bit like a surge protector, and will always be a larger value than the amount you can constantly drive the speaker with. Some manufacturers will only list the Peak Power values of their products, making them appear more robust than they really are. While technically accurate, you'll find that the RMS wattage is actually the true reflection of the speaker's capability.
Understanding Speaker Design
Most (but not all!) loudspeakers consist of at least one cone or driver, a crossover network, and a cabinet.
1) Cones -- The cones are the actual producers of sound, and are thin funnel-shaped pieces of material that vibrate. They can be made of paper, polypropylene, laminated material, or composites like metal, plastic, or graphite. Each cone produces the frequencies best suited to its size. Woofers produce low bass sounds, while the tweeter emits the high frequencies of treble. The midrange falls between the two and produces the majority of sound in the vocal and dialog range.
In a three-way (or three-speaker) design, a dedicated midrange speaker augments the work of the woofer and tweeter. There are advantages to this design, but getting three drivers to work as one can be difficult and expensive due to design and engineering issues.
2) Crossover -- The crossover network works like an electronic switch to send the correct frequency ranges to the right cones. It ensures that the speakers both perform optimally and also don't become damaged by trying to reproduce sound they're not made for. A well-designed crossover network consists of a low-pass filter (LPF), which keeps high-pitched sound from reaching the woofer, and a high-pass filter (HPF), which keeps the lows from seeping into the tweeter. The area at which the LPF rolls off the high frequencies and the HPF rolls off the lows is referred to as the crossover point.
3) Cabinet -- The cabinet is a critical component in the loudspeaker's design, and has a major effect on its sound. A cabinet should be rigid, well braced and internally damped to avoid undesirable sound-colouring vibrations. Plastic cabinets may work fine for computer speakers, but not for serious audio components. Cabinets should usually be made of wood, or, more commonly, medium density fibreboard (MDF).
Subwoofer cabinet design is typically one of two types: a sealed enclosure, or a "bass-reflex" enclosure with an opening which is used to provide a larger cavity for the low frequencies to resonate in. When a woofer moves, it pushes air in two directions, forward and back. Unless dealt with properly, the rear-moving sound wave will bounce off of the back of the enclosure and cancel the forward-moving wave, resulting in poor bass. The port opening of a bass-reflex design gives the back wave a place to go. A properly designed system causes the two sound waves to add together and results in reinforced bass. An alternative and very popular bass reinforcement methodology is called "acoustic suspension." This design uses a sealed box where the trapped air inside acts like a spring. The advantage is that a smaller cabinet can produce very deep bass, however they are less efficient than other designs and require a more powerful amplifier.
An Alternative Speaker Design--Electrostatic Speakers
Electrostatic speakers are gaining popularity among hi-fi enthusiasts and embody a radical rethinking of the traditional cone/crossover/cabinet design. Instead of a cone, they use a thin, flat conductive membrane that is sandwiched in between two electrically conductive panels. The audio signal is sent to the panels, and the voltage difference between them causes the membrane in the middle to vibrate and create sound. There are several advantages to this design. First, they have excellent frequency response compared to traditional speakers because their sound-making surface is much lighter than a regular speaker cone. Due to their flat design, they are also much thinner than traditional speaker cabinets. This makes them highly directional as well, which is great for stereo and surround sound imaging, but it makes room placement an important factor. Finally, while they produce less low-frequency bass than the standard cone design, the quality of bass is typically better and much tighter. Some manufacturers augment low-frequency bass response by pairing a high-quality traditional subwoofer with the electrostatic speaker.
Looking at the Specs--What the Numbers Can and Can't Tell You
When shopping for loudspeakers you'll usually find numerical specifications along with a written description. Be aware though: measurements and numbers tell only part of the picture, and can sometimes be misleading. Here's a checklist of things to look for on the box.
1) Wattage and Power Handling -- As stated earlier, power handling tells you how much power in Watts the speakers can take without damage. Amplifiers and receivers are made to boost the original signal coming from your TV or audio source. It is important to make sure that you are pairing an amplifier or receiver with speakers that are robust enough to handle their output. Remember that the RMS, or continuous, wattage is the true specification for what a speaker can handle for long periods of time. Peak, or maximum, wattage is for brief, loud stabs of music or sound effects.
However, there are several advantages to owning an amplifier that provides more power than your speakers are rated for. As long as you keep the gain (or volume) on the amplifier low, you won't damage your speakers, your amplifier will last longer and the sound will be cleaner. Surprisingly, what usually "blows", or damages, a loudspeaker is using an underpowered amplifier with its gain cranked up to maximum. This is much like keeping the accelerator slammed all the way down in your car. When the incoming signal from your audio source is particularly loud, it will overdrive the amplifier. This causes the amp to "clip" or distort, and that sound is passed to your speakers. Not only does this cause the amplifier to overheat and wear out more quickly, but the loud-level high harmonics in the distortion can destroy the speaker.
2) Frequency Response -- You might read a frequency response specification like "30Hz - 22kHz," but unless it also tells you the variance within however many decibels (+/- 3dB, for example), you're not getting the whole picture. This hypothetical speaker may reproduce sounds as low as 30Hz, but that tone could be 20 decibels below "flat" response. This means that the speaker will vibrate at 30Hz, but does it so softly that you can't hear the sound. Additionally, a speaker's measurement method can affect the frequency response statistic. Was it measured in a normal room or in a reflectionless echo-free (or "anechoic") chamber? Where was the microphone placed to measure the response? A frequency response measurement by itself can give you the wrong impression of what a particular speaker can do. Look for a critical review, frequency response graph or a decibel variance specification. Any of these will highlight possible weaknesses in a speaker's stated frequency response value.
3) Impedance -- This is measured in Ohms and refers to the amount of electrical resistance an amplifier needs to overcome to drive a speaker. Lower impedance ratings require a beefier amplifier to send more Watts to power the speaker. Manufacturers usually list this specification as a single number, however the actual impedance of a speaker varies with the frequency of the signal going to it. Without seeing a graph of the impedance "curve", you cannot know exactly what the rating really is. This information is critical because incompatible speakers can easily damage vintage, tube-style amplifiers. If you own one of these older amplifiers, check the impedance graph of any speaker that you're considering and make sure that it does not exceed the amplifier's impedance tolerance at any frequency.
Modern solid-state amplifiers can safely drive most loudspeakers. This is because many amplifiers are rated at 8 Ohms and higher, while most speakers are rated at a "nominal" (or average) 8-ohm impedance. However, some robust high-end speakers are rated as low as 4-ohms. They require an amplifier that is not only rated at 4-ohms or lower, but is also powerful enough to match the speaker's wattage requirement at that impedance. Before purchasing speakers, check to see that your amplifier matches their impedance and wattage needs.
4) Voltage Sensitivity -- Voltage sensitivity tells you how loud a speaker will play for a given voltage. This gives you some idea as to how big an amplifier you'll need to drive the speakers. This measurement is expressed as a certain number of decibels (dB) per 2.83-Volt input. For example: "88dB/2.83V." Unless you're using a monster amplifier, look for speakers with an efficiency of at least 86dB, though 88dB or higher is preferable.
Finding Speakers That Match Your Music
Your preference in speakers is mainly affected by the kind of music you enjoy most. If you listen to a lot of music that gets played on mainstream radio, you will probably enjoy "coloured" speakers that sacrifice some musical accuracy for additional bass. This is because most mainstream music CDs are mixed to stand out for radio airplay. Their "normalised" dynamic range means that relatively quiet parts of a song are boosted in volume to ensure that the entire radio signal comes through without loss. This engineering also guarantees that songs played over the air can be heard in noisy environments at a steady decibel level. The lowered dynamic range of many popular music albums means that you don't need costly reference-quality speakers to faithfully recreate all the musical nuances present at the time of recording because those nuances have been minimised or eliminated for airplay.
The same principle also holds true for MP3s, most especially those encoded at or lower than 128-kbps. They sacrifice accuracy to achieve a smaller file size, and coloured speakers can add warmth and hide bothersome sound artifacts better than reference-quality speakers. This is especially worth noting because as portable music players such as iPod saturate the market, more and more manufacturers are including iPod and MP3 player docks for their home theatre systems. So if you frequently connect your iPod to your home theatre for music listening, you may want to consider sound-colouring speakers.
More and more albums today don't take the factors of mainstream radio play into account, however. Many niche genres and independently produced albums are carefully engineered to preserve the subtle nuances that were present at the time of recording. Music that features talented vocals, for example, or music with "terraced dynamics" (parts that go from very quiet to very loud and back), really benefit from flat-response speakers that clearly reproduce subtle sonic differences. All kinds of albums from folk to opera to indie-pop rely on unique and varied dynamics in their instrumentation--without being consciously "fixed" or normalized in post-production by a sound engineer who's compensating for expected poor signals on substandard equipment. These kinds of albums deserve the most faithful representation possible. If this is where your tastes lie and you already have a tightly defined budget, you might be willing to find a speaker that gives up the bottom couple octaves of bass to get smooth, accurate liquid-sounding midrange frequencies where more of these sonic details are. However, the best choice for deftly-engineered music of any sort would be speakers that have a neutral response. They allow you to pick through snare hits, layered effect pedals, horn blasts and lyrics--be they barely breathed or vigorously spat--just like the artist wants you to hear them.
What Do I Get for Spending More Money?
First, you should assess what you already have. If you are just starting out, a Home Theatre in a Box (HTiB) solution would be an excellent choice. They typically combine a Dolby 5.1 or 7.1 surround-sound speaker set with an A/V receiver that has a built-in DVD player. HTiB systems take much of the guesswork out of purchasing home audio. Everything comes in one package and it is easy to set up; but the nicest thing is that the speakers are all pre-matched to sound good together. They have a wide range in price and can fit into most any budget, but higher-end systems can really sing right out of the box.
If you already have a surround-sound system, or have been fiercely bitten by the home audio bug, mid and higher-end separate speakers are a fantastic way to take your experience to the next level and possibly even save you money. Cherry-picking your speakers allows you to tailor a home audio solution that meets your exact needs. Also, you don't have to replace every speaker you have, which can both save you money and give you vastly enhanced performance. Upgrading just your front left and right speakers is the easiest way to do this, especially if you listen to music more than you watch DVDs. Adding an upgraded matching centre channel speaker will make stereo transitions seamless, which is crucial for audio systems that are typically used for home theatre. Upgraded rear surround speakers and subwoofers provide added fullness and punch, and can round out a stellar home audio system.
As you move up the ladder in price, better build quality means you don't have to make as many compromises in speaker performance. Those deep, punchy lows get tighter and lose their muddiness, mids become silky-smooth, and highs gain precision. You can crank up the volume without sacrificing clarity. Higher-quality materials result in speakers that are more durable and will last longer than cheaper speakers. Also, manufacturers take pride in their high-end products. Not only do they have enhanced performance, but they are often engineered with very stylish cabinetry that can give your entertainment space an impressive "wow" factor.
The advantage of upgrading your home audio speakers is that it will absolutely cause you to become more deeply engaged with the music you love. Furthermore, when you combine superior speakers with a capable receiver and television, it can create an environment that transports you to other places without you ever leaving the room. Not only will you hear things you've never heard before in your favourite songs, but you can catch all the hidden aural nuances in your favorite movies, experience the crunch of a tackle right on the field and feel explosions going off all around you in your favourite video game. Home audio is about absolutely submerging you in sounds and emotions, and it is the sound that makes the difference between just passively watching, and the experience of actually being there.