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09/06/2008 12:00 AM
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Best Computer Speakers
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Computer speakers nowadays are becoming more sophisticated in achieving the best sound quality for the fast growing market. Speaker systems come in a variety of features with the latest audio technology.
With the popularity of digital music formats, movies, digital video editing and computer games, manufacturers have rapidly developed and produced more and more computer speakers for their consumers. Speakers come in different models and designs, from 5.1, 6.1, to the latest 7.1 speaker systems.
The 5.1 computer speaker system is capable of creating a wonderful listening experience. One of the top quality 5.1 computer speakers is the Logitech Z-5500, with a price of $220. This speaker system tops in almost all reviews. The Logitech Z-5500 can produce heart-pounding bass, very natural mid tones, and crisp sound. It has superb power and accuracy when watching DVDs and when playing computer games.
Theoretically, the 7.1 speaker arrangement (satellite speakers plus a subwoofer) brings existing speaker systems to a higher level. Still, many experts question their value. According to Don Labriola of PC Magazine, "Depending on whom you talk to, 7.
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09/06/2008 12:00 AM
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Things To Remember While Purchasing E-books
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We can easily deduce that Ebook means electronic book. The term is self explanatory. However, it should be noted that the formats may include audio interviews or speeches by an expert in a particular field. People are always very concerned about finding ways to help them solve their problems. Some typical problems that people face could be; they want to stop smoking, they want to loose weight, they want to be in a better position to seduce people of the opposite sex That is where e-books bring their contributions.
The first thing to look at when purchasing Ebooks is the date at which it was written. It is said that when you buy a brand new PC, it is already outdated. This gives you an idea on the speed with which technology changes. The date is particularly important for topics dealing with technology. These could be and are not limited to telecommunications, internet marketing Buying an Ebook which was written a year back if useless as you will get outdated information.
The other thing to look at is the way the seller will deliver you the Ebook you bought. Discourage choosing those who will send it to you by mail.
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09/05/2008 12:00 AM
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Amplifiers
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Amplifier Overview
Your amplifier takes the signal from your head unit and makes it big enough to be able to drive your speakers. It is good to use separate amps for high and low frequencies but it is not needed. The problem with using one amp for all frequencies is that you cannot adjust the levels among different frequency ranges as easily as you can adjust outputs of separate amps. Most people start their system with an amplifier for the low frequencies (bass) and use their head units built-in power to drive the higher frequency speakers. This is enough but the built-in power in a head unit is usually not strong enough for high volume listening and not clean enough for the discerning ear. There are lots of choices when choosing an amplifier.
Things to look for:
RMS Power: The power output of an amplifier should be roughly matched to what the amp will be used for and what speakers it will be driving. Oddly enough, the most usual problem with matching speakers and amps is using an amp that is too weak to power the speaker.
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09/05/2008 12:00 AM
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CAR STEREO REFERENCE MATERIAL
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Car Audio Dictionary:
A: Attenuation, loss of dB. AC (Alternating Current): An electrical current that intermittently changes in amplitude and direction. Acoustic
Fiberglass: Thin fiberglass material used as damping material inside speaker enclosures.
Acoustics: The study of sound.
Air Gap: The space separating the top plate and the pole piece. This is where the voice coil sits.
Alignment: A class of enclosure parameters that gives optimum performance for a woofer with a given value of Q.
Alpha: In sealed enclosure designs, the ratio of Vas to Vb, where Vb is the volume of the box you will build.
Alternator: A device that is turned by a motor to produce AC voltage, which is then rectified (turned into DC) and used to supply voltage to the vehicle's electrical system.
Ampere (A): The unit of measurement for electrical current in coulombs per second. There is one ampere in a circuit that has a one ohm resistance when one volt is applied to the circuit.
Amplifier: An electrical circuit designed to boost the current, voltage, or power of an applied signal.
Amplitude: The relative strength (usually voltage of a signal).
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09/05/2008 12:00 AM
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CAR STEREO WOOFER BOXES
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Enclosures for Car Audio Woofers:
Because woofers move a lot of air they generate a back wave behind them. Mounting a woofer in a open space without an enclosure will cause a loss of bass as the back wave cancels the sound from the front of the woofer. There are many varieties of types of enclosures for woofers to handle this backwave.
A common one is a ported box.
This enclosure has the woofer mounted in box with a hole in it and a port (tube) attached to the hole. The port is made a specific size and depth to cause a "bump" or rise in the frequency response at that point. This makes the overall system more efficient but can lead to the bass to be somewhat "boomy" or less "tight" depending on how its done.
A newer technique is a bandpass enclosure. The woofer is mounted inside the box and fires into another chamber within the box that is ported to the outside. Again, this increases efficiency significantly but only at a certain frequency. This effect can make the system very loud and boomy.
The oldest and most popular type is a sealed enclosure.
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