Speakers are one of the most common output devices used with computer systems. Some speakers are designed to work specifically with computers, while others can be hooked up to any type of sound system. Regardless of their design, the purpose of speakers is to produce audio output that can be heard by the listener.
In most respects, computer speakers work in exactly the same way as other speakers. An oscillating signal flows down the speaker wire from the computer into the speakers. This signal looks like a sound signal in that it gets stronger and weaker thousands of times each second in a pattern that corresponds to the sound being played. Most computer speaker systems actually have two signals–one for the left speaker and one for the right.
At the front of a loudspeaker, there is a fabric, plastic, paper, or lightweight metal cone (sometimes called a diaphragm) not unlike a drum skin (colored gray in our picture). The outer part of the cone is fastened to the outer part of the loudspeaker’s circular metal rim. The inner part is fixed to an iron coil (sometimes called the voice coil, colored orange in the diagram) that sits just in front of a permanent magnet (sometimes called the field magnet, and colored yellow). When you hook up the loudspeaker to a stereo, electrical signals feed through the speaker cables (red) into the coil. This turns the coil into a temporary magnet or electromagnet. As the electricity flows back and forth in the cables, the electromagnet either attracts or repels the permanent magnet. This moves the coil back and forward, pulling and pushing the loudspeaker cone. Like a drum skin vibrating back and forth, the moving cone pumps sounds out into the air.
Computer speakers, or multimedia speakers, are speakers sold for use with computers, although usually capable of other audio uses, e.g. for an MP3 player. Most such speakers have an internal amplifier and consequently require a power source, which may be by a mains power supply often via an AC adapter, batteries, or a USB port (able to supply no more than 2.5W DC, 500mA at 5V). The signal input connector is often a 3.5 mm jack plug (usually color-coded lime green per the PC 99 standard found at back of computer cases); RCA connectors are sometimes used, and a USB port may supply both signal and power (requiring additional circuitry, and only suitable for use with a computer). Battery-powered wireless Bluetooth speakers require no connections at all. Most computers have speakers of low power and quality built in; when external speakers are plugged into the Line Out connector of the sound card, they disable the built-in speakers. Altec Lansing claims to have created the computer speaker market in 1990.
Listening with both ears: stereo, quad, and binaural
When sound comes from a single loudspeaker, we say it’s mono or monaural. Mono is like the sound of one person talking: the sound source is fixed in one place. Technically, true stereo means sound recording and sound reproduction that uses stereographic projection to encode the relative positions of objects and events recorded.
The difference is in the number of channels (signals) used. Mono uses one, stereo uses more than one.
- In monaural soundone single channel is used. It can be reproduced through several speakers, but all speakers are still reproducing the same copy of the signal.
- In stereophonic soundmore channels are used (typically two). You can use two different channels and make one feed one speaker and the second channel feed a second speaker (which is the most common stereo setup). This is used to create directionality, perspective, space.
Although stereo is a big improvement on mono, it’s still only two-dimensional sound. It is possible to make loudspeakers sound three-dimensional, but you need more speakers to do it. Quad (quadrophonic) sound is like double stereo: you have two speakers in front of you and two behind. Now the sound can move behind you or in front as well as from side to side. Surround sound used in movie theaters (cinemas) works in a similar way.
WHAT TO LOOK FOR IN SPEAKER SPECS
To experience quality sound, speaker watts are one figure to understand and consider. Other important values are the speakers’ sensitivity and total harmonic distortion (THD).
Frequency response describes the range of audible frequencies the speaker can reproduce between 20 Hz (deep bass) and 20 kHz (a piercingly high frequency), which is considered the range of human hearing. In reality, our hearing does not typically extend up to 20 kHz (especially as we get older), and bass frequencies below 30 Hz tend to be felt more than heard.
The most meaningful ratings include a plus/minus deviation (±3 dB is typical), which indicates how far the sound deviates from a neutral or “flat” response; the lower the number the better, although in practice, speaker placement and room acoustics greatly affect what you hear. Still, the number at the lower end of the range gives you an idea of how low the speaker can play. For example, a rating of 50Hz – 20kHz ±3 dB means you will need to add a separate subwoofer if you want to reproduce the deepest bass.
Sensitivity is most easily defined as the speakers’ ability to effectively convert power into sound. The traditional way of measuring a speakers’ sensitivity is using the standard of 1 watt/1 meter. Meaning a microphone is placed 1 meter away from the speaker to measure the sound output (in decibels) with 1 watt of sound played through it. There is much room for error (or imposed error) with this type of measuring system and some manufacturers today take advantage of this.
Most speaker sensitivities are in the 85 to 91 dB range, so anything less than 85dB is not so hot. How Do Watts Translate Into Decibels?
Numbers are for reasonably sensitive speakers, about one meter away. Look for speakers that can handle between 85 dBs and 110 dBs. Anything more than this will destroy your hearing. For mid-price home speakers, 120 watts is about the most you should
Sound-pressure level (volume) is expressed in decibels: the higher the number, the higher the efficiency. Numbers in the mid-80s are typical, while anything over 90 dB is considered excellent.
Impedance sheds no light on sound quality but tells how much strain the speaker places on an amplifier. The lower the number, the more strain; most speakers are rated at 8 ohms, which is considered an easy “load.” If you come across 4-ohm speakers, just make sure the amplifier driving them can handle the extra load (most good quality amps can).
A subwoofer (or sub) is a woofer, or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audio frequencies known as bass. The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound and below 80 Hz in THX-approved systems. Subwoofers are intended to augment the low frequency range of loudspeakers covering higher frequency bands. While the term “subwoofer” technically only refers to the speaker driver, in common parlance, the term often refers to a subwoofer driver mounted in a speaker enclosure (cabinet).
Types of Speakers
Among the types of computer speakers, some of the most commonly used would be the two-speaker system which does not take up too much space and provides good sound quality.
2.0 Computer Speakers
It is one of the most basic and commonly used speakers. It has a relatively small speaker driver which allows it to have a more compact design that takes up minimal space on your desk but it also produces less powerful bass frequencies.
Gives a better listening experience as it is designed to provide sound separation, consisting of a left and a right speaker. Its amplifier is located inside one of the speakers for its enhanced sound volume quality.
2.1 Computer Speakers
Similar to the 2.0 speakers, the 2.1 computer speaker also has a pair of satellite speakers, a left and a right that is placed above your desk, but compared to the 2.0 speakers it has a much larger speaker-amplifier.
The satellite speakers are smaller than the 2.0 speakers because they do not need to produce lower-frequency bass sounds since it has a subwoofer that produces it. If you’re looking for a speaker that produces strong sounds for listening to music or watching videos, then choose the 2.1 computer speakers.
5.1 speaker setups consist of 5 satellite speakers and 1 subwoofer. These systems are the most common surround sound setups in use today. Offering multi-channel output, surround sound systems are excellent for movies and video games, as they give the viewer a more “engulfing” audio experience.
The 7.1 speaker system is one of the most complex systems, consisting of 7 satellite speakers and 1 subwoofer. These allow for some of the most precise surround sound environments provided that the source media can output that level of accuracy–otherwise the output will actually output 5.1 surround sound. Keep in mind that 7.1 systems will cost you: they start around $300.
Surround Sound Speakers
The surround sound speakers can turn your place into a movie-theatre like ambiance. It varies from 5.1 channel to 9.1 channel and even higher. The 5.1 channel system consists of 5 satellite speakers, a pair of front satellite speakers and three additional speakers to augment it and 1 subwoofer for an immersive sound effect.
The higher the channel number, the more speaker isprovided for a more intense movie experience. The surround sound speakers offers multi-channel output which makes it excellent for watching movies and playing video games as it gives those using it with a thrilling audio experience.
Wireless Computer Speakers
More recently, wireless speakers have allowed users to avoid the mess of wires associated with surround sound speaker setups. While these are excellent for many users, they can often conflict with a home Wi-Fi network.
Wireless computer speakers are what most people desire; something portable, that we can use anytime we want and be able to carry it with ease anywhere we go. We usually carry with us our smart phones or gadget as a medium of storage for the songs we like to listen to, movies or videos that we would like to watch anytime we want.
Having a portable wireless speaker on hand makes it easier for you to share to your family or friends your favorite songs and movies and play them out loud so that they too can join in on the fun.
When choosing wireless computer speakers, you will need to consider not only the quality of the speaker but also the type of wireless technology it has like Bluetooth, Wi-Fi or Apple’s Airplay.
Tips in Buying Computer Speaker
- 0 speakers are good for regular computer usage.
- 1 speakers have a subwoofer to produce low bass frequency bass sounds which makes it better for listening to music.
- Surround sound speakers lets you experience strong sounds for watching movies and for playing video games.
- The wireless computer speakers offers you great sound systems and portability which lets you use it anytime you want and anywhere you are.
- Look for extra sound inputs if you’re looking to connect your speaker to multiple devices.
- It makes it easier for you to adjust the volume and bass/treble if your speakers come with on-board controls.
- A good sound card can make a big difference over onboard sound if you have the speakers to match. As of right now if you using headphones or a 2 speaker setup and when you get these speakers you will hear a big difference.