How To Measure Car Speakers? – 4 Most Important Diameters

Car speakers are an indispensable component in a complete car audio system. This kit comes in many sizes. Depending on what type your head unit is compatible with, you can decide the most suitable one for yourself. However, “What to do to measure car speakers?” is a question with many considerations when you need to know how and which diameters are essential. The following article will answer your questions.

How To Measure Car Speakers?

Car speakers include four main diameters: mounting depth, height, mounting screws diameter, and cutout diameter. Each needs different knowledge and techniques to determine the best.

Mounting Depth

Accurate mounting depth prevents movement blocking - How To Measure Car Speakers

Mounting depth lets you know the best distance for your gadget to mount to the setup without causing the magnet to collide with nearby objects such as the door panel or car door.

In other words, it speaks to the depth of the speaker relative to the cabinet to avoid buying the one with too much depth. Because when the speaker is too deep, besides not being able to fit properly into the system, it also causes movement blocking for other objects.

Flip the device over and position it on a level surface with the cone facing up to determine the mounting depth. Next, measure the distance between the flat bottom surface of the speaker and the bottom of the mounting frame.

Mounting Height

Mounting height of a speaker

Mounting height is the height from the mounting flange to the highest point of the car speaker. It helps you calculate the size of the speaker grills so that they don’t collide with other objects.

Especially with coaxial speakers, the tweeter is always mounted higher than the surface. So defining the height to mount is of the utmost importance.

To rate this height, you need two rulers. Also, place the gadget with the cone facing up, similar to the depth. Then place a ruler on the mouth of the speaker so that it is parallel to the frame. Use the other ruler to measure the distance between the former one and the mounting frame.

Mounting Screws Diameter

We need to measure two important things about the mounting screw: its diameter and the distance between the screw holes. Distance and diameter help you accurately predict where the speaker is most stable.

The diameter of a screw is the distance between two screw holes diagonally opposite each other. It is easier to determine with an item with an even number of screws because all you have to do is measure two holes across from each other.

However, for devices with an odd number of holes, such as 3-hole speakers, the measurement will be more complicated when you need the specifications on the product packaging to know exactly.

To study the distances and diameters, you need to use a ruler and tape to measure the distances mentioned above.

Cutout Diameter

To make it easier to imagine, when installing the kit, only a small part of the device sticks out from the plane, and most of the rest is in the mounting depth of the speaker. Therefore, the diameter of the section in contact with the plane or the bottom side of the speaker flange is the cutout diameter.

The cutout diameter is the most critical measurement to determine the basket, thereby helping the device be installed properly, without moving, and without causing the basket to be distorted or damaged.

Usually, when measuring, people often choose their own one with a cutout diameter slightly smaller than the basket to help minimize damage when mounting.

To quantify this diameter, we turn the speaker upside down so that the magnet faces up. Then, use a ruler and measure the widest part of the cone attached to the back of the speaker frame.

Why Is It Necessary to Measure Car Speakers?

Each speaker has its own size

Usually, they are classified into speaker sizes like 6.5″, 6×9″, etc. However, it is a fact that not all 6.5″ ones have the same size 6.5.

You can always find a difference of a few millimeters between devices of the same size. However, such small differences still affect installation. 

And if the size doesn’t fit or “nearly fits”, it will cause problems with surrounding devices, distort and damage the room if it is, unfortunately, a bit larger, or cause looseness. Loose, unstable if it is smaller.


The article above has answered the question of “What to do to measure car speakers” by giving some critical diameters you need to note when measuring.

Understanding the working mechanism of a car sound system components is required for installing a good audio system.

If you found the above article interesting and want to learn more about vehicles and auto gears, please leave a comment or visit for additional information.

Thank you for reading!

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