Saturday, May 05, 2007

Understand Your Coaxials Speakers

(Earthquake VTEK Cozxials)

The least expensive and most common type of car speaker is the coaxial. The coaxial consists of a midrange/woofer with a tweeter placed over the cone, either on a bridge or on a pole that extends from the middle of the cone. These speakers are made in sizes that will exactly fit most brands of vehicles. Advantages of this design include low cost, ease of installation, and a speaker that more closely approaches the one loudspeaker ideal, also called a point source, where all frequencies appear to originate from the same location. The disadvantage of this design is a generally lower sound quality for the majority of coaxials available versus the majority of matched component sets available.

Aspects and features that need to be considered when purchasing coaxials are:

Frequency Response: This is the how much of the audible spectrum a loudspeaker can reproduce. The value should be given with a rating of +/- some number of decibels, usually three. The greater the frequency range, the better up to 20kHz and down to 20Hz. Realistically a coaxial speaker will not play much below 80Hz. That's why we have subwoofers.

Mounting Depth: This is the distance that a speaker needs behind its mounting surface for its basket and magnet structure. This can be very important when speakers are being installed in the rear deck of automobile that has torsion bars in the trunk or door speakers with window clearance problems.Power Handling: This is the amount of power a speaker can withstand before failing after a given amount of time. The most important number is the speakers continuous or RMS (root mean square) power handling. Peak power handling means virtually nothing.

Sensitivity: This is a reference measure of how loud a speaker will be with a certain amount of power at a certain distance. The standard is one watt at one meter. By halving the distance an increase of six decibels will be realized and doubling the power will increase the output by another three decibels. This is a trick used by some companies to make their speakers appear more efficient than they are. Most loudspeakers will be in the ninety decibel range. Keep in mind that a difference of three decibels is equivalent to a doubling of the amplifier power.

Tweeter Protrusion: The height that a tweeter sticks above its mounting surface. This will need to be considered when coaxials are being mounted in factory locations under factory grills.

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