Please 'Boom' Responsibly As most of you have noticed, the noise ordinances have become much tougher lately. Most of this is due to idiots, yes IDIOTS, who drive through residential areas with their windows down while their system is playing at full power. To make things worse, the music they listen to has all sorts of foul language that's not suitable for small children, (who may be playing outside). There are even a few people, who are even beyond idiot status, that play their systems at full power through residential areas after 10:00 PM (when many people go to bed). I don't believe that this type of behavior is good for the industry. If the fines get too stiff, people will stop buying large systems. If this happens, more people will get out of car audio (who wants a mediocre system). People get interested in things because they're exciting. A deck and four 6.5" speakers are not going to interest many of the younger car audio enthusiasts. If car audio enthusiasts keep annoying more and more people, the fines will keep getting tougher. All of this will only reduce interest in the equipment that fuels the industry. If you want to listen to your system at full volume, get out on the highway where there's little chance of bothering anyone. When you get to a red light, turn it down. If the only thing attractive about you is your 'system', you have some work to do. Bottom line... Think about what you're doing. Think about other people. It's not the end of the world if you have to turn the volume down for a little while.

Basic Audio System Review:
The first link in the car audio chain is the head unit. The head unit most commonly contains a radio receiver and a mechanism for the playback of a recorded medium (tape or cd). The head unit can have speaker and/or preamp outputs. The speaker outputs will have enough current and voltage capacity to drive speakers. The preamp outputs do not have the current capacity to drive speakers. They are made to drive a high impedance input of an amplifier or equalizer. If your system has multiple amplifiers then you may need to put an electronic crossover between the head unit and the amplifiers. If the system has some part of the audio spectrum that is too loud or too low, then you may need to add an equalizer of some sort.

This diagram shows the head unit's RCA output jacks driving the RCA inputs of the amplifier. The signal is a full range signal which, as you can see, is reflected in the frequency response graph. It shows that all of the frequencies across the audio spectrum are being reproduced at the same level. The relative signal levels of the head unit's output and the amplifier's output are shown by the sine waves in the upper right hand corner of the diagram. You can see that the output from the amplifier is larger in magnitude (because the amplifier amplifies the head unit's output signal). In a real system, the difference in magnitude between the two waveforms would actually be much larger than shown but you get the picture (or the diagram :-). Simple audio system
In this diagram, you see a slightly more complicated system. This system uses a 2 way electronic crossover. You can see that the full range signal from the head unit is divided into high and low frequencies. The high frequencies go to the amplifier that drives the mid and high frequency speakers (let's pretend that the speakers shown are coaxials). The low frequencies go to the amplifier that drives the woofers. The two groups of frequencies are seperated to prevent the bass from damaging the smaller speakers and to filter the high frequencies from the low frequency amplifier and speakers (which would make the woofers sound like... well, you fill in the blank). The frequency response (on the graph) is color coded to each amplifier. The frequencies represented by the blue line are being sent to the blue amp. The frequencies represented by the red line are being sent to the red amp. System using a 2 way crossover
backward If you find a problem with this page or feel that some part of it needs clarification, E-mail me.

This is a link to this site's home page.

forward