car subwoofer, is an important part of modern car audio system, the subwoofer is everyone coaxial speakers, tweeter Aberdeen, treble A commonly known as deep bass. Subwoofer provides a more natural music for many music lovers, especially for driving out the people who make fun driving on the way, give the driver a great deal of enjoyment.
1. The car subwoofer works
Inside the power amplifier circuit, a frequency divider by sound into several frequency bands, the output of the high frequency band to the satellite speakers, the output of the low frequency band bass gun, generally emit low-frequency sounds 20-200HZ subwoofer, and when energy is not a very strong person is difficult to hear, and very, very difficult to distinguish the orientation of the sound source, such low-frequency sounds heard by a phase inversion hole, and satellite Loudspeakers resonance, low-frequency satellite speakers and the speakers produce weak bass speakers combine satellite speakers speakers will re-release bass horn performing arts, so bass is very shocking, but the feeling is the same as people sent from the satellite speakers speakers there.
As to why ultra-low frequency speaker and low-frequency resonant horn, then use physics knowledge to understand: GuardianStar bass is weak, it can be heard, the amplitude of the waveform thereof is small, i.e., energy is not big enough, when the ultra-low frequency speaker to produce overlapping therewith, since the hole through the inverter, which leads to uniform phase, then loaded into the super low frequencies satellite bass waveform, because the speaker has a very strong power, after loading a sharp increase in energy that makes you feel very shocked.
2. The car subwoofer configuration
For analyzing circuit subwoofer, typically amplified by pre-stage, low-pass filtering, the phase adjustment, power amplifier, and other components and power protection.
on its role, the preamplifier is the bass signal output from the AV amplifier is further amplified to an amplitude sufficient to drive the power amplification section full power output, because the bass signal voltages of the respective grade AV amplifier provided not the same, generally ranging from 0.3 to 1 volt, so the preamp is necessary, there is an important role of front-end circuit is buffered from the sense of isolation, because of differences subwoofer amplifier output signal for each grade, there manufacturers steal material in the design, so that the output resistance is high, if the direct drive subwoofer power amplification unit, it is possible to effect very bad;
subwoofer low pass filter is a comparator circuit section gUN important unit, its role is more mixed in the amplifier output signal subwoofer low frequency signal is further filtered, the general design 80-180Hz (many high-end product will lower cutoff frequency of the filter is designed to be continuously adjustable ), if the filter belongs to a fixed frequency, the general value of around 110-150Hz, too prone speakerMixed down sound, too, a music signal is mixed readily discernible to the human ear;
bass signal for each grade AV amplifier output is inverted or not uniform predetermined normal phase, therefore, the phase adjustment is when the subwoofer may be necessary to place the subwoofer connected to the positive phase or reverse phase system using, depending on desired effect, generally essential;
power amplifying unit would not wordy, an active subwoofer where the core;
also, to protect the safety and subwoofer protect equipment from being damaged without exception or fault valuable expansion member, the protection circuit is also generally necessary;
[123 ] is the power supply of each circuit unit of work, is an essential part.
It should be added that some of the recent subwoofer also designed an automatic power control function, so that the subwoofer automatically turn off the main power supply in the absence of the subwoofer signal.