A Complete Guide to Car Speaker Sizes

If you are new to car audio and not sure what type of speaker does what in the system, you can use the car speaker sizes of the units to get a good idea of how the speakers are used in your vehicle. Generally speaking, the size of a car speaker determines the frequency of the sound that is emitted from the speaker. The only exception to this principle would be when a car speaker integrates several types of speakers into a single enclosure. This article is meant to give you a better understanding of car speaker sizes and what they mean.

Coaxial Speakers

Coaxial speakers are the type that generally contain 2 or more types of individual speakers in a single enclosure. For instance, a coaxial speaker may have a bass woofer and tweeter integrated into the same enclosure. These types of speakers may be round or even oval in shape. Most of the time, coaxial speakers are either 6 or 8 inches in diameter if they are circular, and are usually 6 by 9 inches when they are oval. These types of speakers are usually installed into the doors or area behind the backseat in a vehicle. The area beneath the rear window glass and above the trunk is a popular place to install speakers of this size. These type of speakers usually don't require the additional installation of other speakers to cover the audible spectrum of sound.

Mid-Range Speaker Sizes

Mid-range speakers are those designed to produce frequency sounds in the range of 1000 to 6000 Hz. This is considered to be the mid-range of the audible spectrum. These types of speakers are usually 4 to 6 inches in diameter and are almost always circular in shape. Although these types of speakers are adequate for listening to the voice range of most humans, they are not suitable for listening to music. This is because they don't produce the high and low frequencies that are needed to enjoy the whole spectrum of music audio.


Tweeters are generally the smallest types of speakers you will see in an automobile. In general, they are usually between 1 and 3 inches in diameter and may be installed in the door trim, ceiling or any other part of the vehicle. Tweeter speakers are used to produce the highest frequencies of audible sound. In fact, tweeters are used to produce frequency sounds above 6000 Hz all the way up to the frequency level limit of human hearing which is about 17,000 to 18,000 Hz.

Bass or Subwoofer Speakers

Bass or subwoofer speakers are usually the largest types of speakers you will see in a car. In fact, the larger the speaker, the more  bass sound it will usually create. For this reason, most bass or subwoofer speakers are usually larger than 8 inches. Sometimes, you may even see subwoofer speakers that are 18 inches or even larger. These types of speakers are designed to reduce the lowest audible sounds. A typical bass or subwoofer speaker can produce sounds that range from about 60 Hz all the way up to about 800 or 1000 Hz. These types of speakers are usually installed in the trunk or rear area of a vehicle.