Features: Magazine | Literary Review | Life | Metro Plus | Open Page | Education Plus | Book Review | Business | SciTech | Friday Review | Young World | Property Plus | Quest | Folio |

SOUND BYTES

BOOST THAT SOUND!

For the uninitiated, here's a little glossary to use while shopping for an amplifier for the car stereo

Bridgeable

This allows a pair of amplifier power channels to be combined into one channel of greater power. This is generally used for driving a subwoofer although it will work with any other type of speaker as well.

Channels

The amplifier's installation flexibility increases based on the number of channels on the amplifier. The more the number of channels, the greater is the installation flexibility of the amps.

Class

This refers to the way the amplifier operates. The three types that are most likely to be encountered are A, A/B, and D. Class A amplifiers are the least efficient in terms of power consumption, but they sound better than A/B amplifiers. Class A/B amplifiers are more efficient than class A designs and are the most common type. Almost all amplifiers in the car audio market are of the A/B design. Class D amplifiers are usually reserved for high power sub-woofer amplifiers and can reach efficiencies in the 80 percent plus range. This design can therefore be smaller. It also uses less current and produces less heat than the other classes.

Connectors

A method used to attach wires. The most common kind is a screw terminal strip. This is used in order to connect the amplifier with speakers. There is a series of screw connectors that can be removed and replaced without compromising the amplifier.

Crossover/ Filter

A built-in crossover can be useful, especially if it can handle many frequencies of adjustment. A filter is a crossover that only affects one channel and does not actually split frequencies, but simply reduces a range of them.

Distortion

THD or Total Harmonic Distortion. It is the measure of how much an amplifier will change a signal from the input signal it is fed with. Figures below 0.1 percent are negligible and will not be heard. Usually, the figure can be in the three percent range without being heard. Virtually all high quality amplifiers will have a THD below 0.1 percent.

Efficiency

This is the ratio of the power input (from the battery) to power output (to the speakers). A 100-watt amplifier with an efficiency of 50 per cent would take in 200 watts of power from the battery and output 100 watts of power to the speakers. The other 100 watts of power would be wasted as heat. It is a known fact that the higher the efficiency of an amplifier, the better.

Power Output

The rated power output of an amplifier is usually given in a four ohm load, all channels driven from 20Hz-20kHz.

Power Supply

The two most common types are the MOSFET supply and the IC chip. While MOSFET is the more common design and has a smoother sound than the chip design, the IC chip is what is used in most source units (head units) and are only capable of producing about twenty watts per channel.

Printer friendly page  
Send this article to Friends by E-Mail