Car tweeters are designed to produce higher pitched sound waves, and are often used modularly within your vehicle. Tweeters supplement woofers because woofers produce the lower and mid-range notes while tweeters cover the higher range. Tweeters must be used in conjunction with woofers. Tweeters are made with a variety of materials such as, Mylar, Titanium, Aluminum, Silk, and other hard and soft materials. Solid diaphragm tweeters provide a more cymbalic sound while softer materials such as silk provide smoother well rounded notes.
Car tweeters are designed for the higher ranges in music, such as for classical sounds involving the violin and piccolo or for the screaming beats of hair metal. The tweeters are designed to most accurately reproduce the highest ranges, including the inaudible sounds that can still add a subconscious element to the sound being reproduced.
Tweeter Audio Ranges
The use of car tweeters is when your choice of music or other audio is specifically going to include clear, sharp high notes. As a general rule, anything above the 3,000 Hz range of sound is going to be filtered to the tweeters in your vehicle. Since the human ear can hear up to 20,000 Hz or 20 kHz, some car tweeters cut off around that range. However, in some cases having notes above 20,000 can be useful for adding a subconscious element of "feeling" the highest range of sound. This generally feeds from your individual preferences.
Types of tweeter diaphragms
Car tweeters come in a variety of sizes, with varying levels of sound quality. The most basic are cone tweeters, which is essentially a paper cone. Next are semi-dome, followed by dome tweeters. Some would argue that inverted-dome focal car tweeters allow better sound radiating and efficiency along with the better control that cones generally provide.
The materials of your tweeters can range between simple paper, synthetic films like mylar or PET, textiles like silk, and metals like aluminum. Paper is generally the worst due to its cheap construction, while synthetic films are great against humidity and are easy to drive in low-power situations, they tend to be less accurate. Often, silk is used if humidity is not a major issue due to its smoother refined sound quality. Metals domes are used when you desire extra crisp and metallic type upper notes but use more power which requires an amplifier.
Cooling and Directing
Often your car tweeters can use wave guides to direct the sound radiation pattern of your system. This can keep the high notes broadcasting evenly and image your stereo sound more effectively to where you are sitting. Higher end tweeters utilize heat dissipation systems such as ferro-fluid cooling within your tweeter's voice coil. The use of both of these can result in a higher quality of sound reproduction and more longevity.