Automotive audio and speaker matching issues related issues

The car audio market an array of products, including host, power amplifier, a loudspeaker, a processor, audio-visual equipment. Only a host, there are CD host, VCD host, DVD host, with MP3 functions of the host and other types of. The world's various well-known brands more than the number of products to a billion dollars, but to build a set of sound basic collocation, but it is a skill, all kinds of equipment need to be carefully selected for collocation to get the best results.
　　Then, the car audio power amplifier and speaker is any collocation?
　　Power amplifier and speakers only do impedance matching and power matching and frequency matched in order to ensure the safe operation of equipment and charge distribution exhuming the largest potential.
　　What is impedance matching?
　　Aside from the dull theoretical knowledge, the simple explanation is that the power amplifier can withstand a certain range of impedance. Only the speaker is connected to the speaker's impedance in the range, and the power amplifier can work safely and provide the most ideal power output! Different types of power amplifiers can withstand the impedance is different. For example: ALPINE MRV series power amplifier is rated impedance is 4 ohm (4 ohm per line), MRD series of rated impedance is 2 ohm.
　　Power matching is what?
　　We must first find out the two kinds of indicators, the maximum power and sustained output power (RMS).
　　There are a lot of brands of power amplifiers and speakers used to judge the pros and cons of maximum power. In fact, this is not a scientific evaluation method. Maximum power of nominal is without considering the distortion and equipment in a very short period of time (usually only a few milliseconds) within the physical damage or electrical damage when the power value.
　　Sustained output power (RMS) is a power that can be sustained and stable without distortion. Only this value can really reflect the working state of the device.
　　Usually a lot of people may cause the main factor that the speaker coil burned is the power amplifier's power greater than the speaker. So when the device is collocation, the power of the speaker is greater than the power amplifier. This is a very common mistake!
　　In fact, the continuous output power of the amplifier is less than the continuous output power of the speaker is most likely to lead to the destruction of the speaker. Because if the power amplifier of the continuous output power 100W, the speaker's sustained output power 200W. Once the connecting system, once the adjustment of the volume knob, the output power of the 100W, the power amplifier has been at full load operation state. While the speaker has a lot of margin, once the user to continue to improve the volume, this time the output power exceeds the power amplifier's sustained output power, that is, the distortion of the beginning of the moment! This distortion is known as "clipping distortion", known as the "speaker killer" in the professional audio industry ". This distortion of the signal, even if the power is very small can produce a similar direct current electrical signal, it is easy to burn the coil of the speaker! For a continuous output power 200W speakers, the distortion rate of 50% of the 150W signal is more terrible than the non distortion 300W!
　　So in the field of professional audio, to maintain the "margin" of the power amplifier is an important factor in the system collocation. It is used to ensure that the continuous output power of the bass power amplifier is 2 times more than the continuous output of the speaker! In car audio, because the power of the car is very limited, the power of each 1W is precious, so that the continuous output power of the power amplifier is slightly larger than the continuous output power of the speaker is the best choice. Don't let the continuous power amplifier to drive the continuous output power of a large speaker. I cannot but do so, attention should be paid to control the volume, to prevent the emergence of clipping distortion!
　　Frequency matching
　　Power amplifier is usually divided into full band amplifier and bass special power amplifier. The bass special power amplifier in the signal frequency is 250Hz the following can guarantee the distortion is less than 1%. And when the frequency exceeds 250Hz, the degree of distortion is soaring, the output power is suddenly reduced. So don't try to push the midrange and tweeter with special bass amplifier.
full band power amplifier is usually used in AB class amplifier design, power consumption is relatively large. So it is the best choice to remove the signal of the low frequency band, which will only push the high frequency speaker to save power and ensure the sound quality.
　　As long as the collocation principle of the above devices, it is essential to ensure that the speaker and power amplifier for security, and to restore the pure and no distortion sound.