Replacing the regular acoustics in the car is often the first step to sound quality, but this process can turn into a real quest if you do not know what you want to do. How to measure the size of the speaker in the car. Many motorists make the mistake of relying solely on the markings on the old column or the standard dimensions listed on the Internet for a particular car model. In reality, factory seats can be non-standard, modified by previous owners or have unique geometric features.
Incorrect selection of speakers by diameter or depth of landing leads to the impossibility of installation, damage to the diffuser on the door card or even to a short circuit if the magnetic system touches the metal elements of the structure. To avoid unnecessary costs and the need to manufacture complex adapters, it is necessary to conduct competent measurements. landing-place and free space. In this article, we will discuss all the subtleties of taking measurements, using tools and interpreting the obtained data for the selection of ideal acoustics.
Accuracy is everything: a mistake of even a few millimeters can cost you the opportunity to install the desired model without modification. We will not only consider standard diameters, but also critical parameters such as: setting-depth And a mounting takeoff. Understanding these nuances will allow you to feel confident in the autosound store and choose a component that will stand “like a poured”.
Necessary tools for accurate measurements
Before starting to dismantle the door cards or shelf, it is necessary to prepare the appropriate tools. A conventional school line here will not be enough, as it does not allow you to measure the depth of the hole or the inner diameter with high accuracy. You'll need it. rod-barIt is preferably with a depth meter that will provide accuracy up to a millimeter. If there is no professional tool, you can use roulette, but the error will be higher.
You will also need a set of screwdrivers and plastic blades to neatly remove the door lining to access the back of the speaker. In some cases, a flashlight may be needed, as the niches in the doors are often darkened. Don’t forget to prepare a notebook or smartphone to record the values obtained, so as not to confuse the left and right speaker parameters, which may differ in different trim levels.
It is important to understand that you need to measure not the speaker you are planning to buy, but rather, the speaker. landing-place in the car. Even if you are changing the burnt speaker to a new model, the measurements are worth checking, as the previous owner could install acoustics through the supply rings or cut plastic. Using a precise tool eliminates the risk of buying inappropriate equipment.
☑️ Measurement instruments
Main parameters: diameter, depth and departure
There are three key parameters that determine the compatibility of the speaker with your car. The first and most obvious is diameter. However, it is important to distinguish between the outer diameter of the housing, the diameter of the fastening holes and the diameter of the diffuser. In autosound, the standard is the diameter of the mounting holes or the outer dimension, which should enter the normal door opening without clogging the plastic.
The second critical parameter is setting-depth. This is the distance from the speaker’s mounting plane to the deepest point of the magnetic system or basket. If the depth of the speaker exceeds the available space in the door, the diffuser will rest against the inner wall of the door or window lift, which will lead to wheezing and rapid failure. The third parameter is landing, that is, the height of the front part of the speaker, which should be freely placed under the decorative grille.
Always measure depth with a margin of 5-10 mm, taking into account the amplitude of the diffuser stroke when playing bass.
Often, the car owners forget about the magnetismIt can be wider than the speaker body itself. When measuring depth, the widest part of the structure must be considered. If the magnetic system is wide, it may not enter the normal hole even at normal depth. Therefore, measurements must be made in several planes, presenting the speaker as a three-dimensional object, and not a flat circle.
- 📏 Diameter: measured at the outer edge of the shell or at the centre of the anchorages.
- 📉 Depth: The distance from the adjoining plane to the end of the magnet or basket.
- ↔️ Departure: height of the front part, including the protective net and frame.
- 🔩 Fastening: diameter and number of screw holes (usually 3 or 4).
Step-by-step instructions: how to correctly remove measurements
The measurement process begins with the neat dismantling of the door map. Don’t pull the plastic sharply, use plastic shoulder blades to snap clips. After removing the card, you will get access to the speaker. If the speaker is still installed, measure its outer diameter and depth, but remember that it can stand through the adapter. Therefore, the ideal option is a complete dismantling of the acoustics to measure clean landing-hole in the metal of the door.
To measure the diameter, apply a ruler or a bar to the opposite edges of the hole. If the hole is oval (which often happens in regular places), measure the smaller size - it will be the limiting one. To measure the depth, lower the ruler or depth meter into the niche to the point in the obstacle (glass, amplifier, metal door) and fix the value. Make sure there are no wires or windows in this area that can block the path of the magnet.
⚠️ Attention: When measuring depth, be sure to lower the glass to the end and spin the window handle to make sure the mechanism does not cover the space for the magnet in extreme positions.
Write down all the data you've received. If you plan to install component acoustics, separately measure the place for installation. RF headers (Beeping) Often they are non-standard shape or require milling plastic. Also check the thickness of the metal around the hole: if it is thin, you may need to strengthen the mounting site so that the speaker does not rattle at high volumes.
Standard dimensions of automotive acoustics
In the automotive industry, a number of standards have developed, which are guided by manufacturers of head devices and acoustics. Knowing these standards will help you to navigate the nomenclature of products faster. However, it is worth remembering that the “standard” in the automotive industry is stretchable, and tolerances can be several millimeters in both directions. The most common size for frontal acoustics is 16-17 cm.
Below is a table of correspondence of inch dimensions, centimeter values and diameter of the seat. Please note that the actual diameter of the hole in the door may differ from the diameter of the speaker by 2-5 mm in the large side for ease of installation.
| Inch-size | Metric analogue (cm) | Hole diameter (mm) | Typical installation site |
|---|---|---|---|
| 3.5" | 8-9 cm | 80-90 mm | Back shelf, racks. |
| 5.25" | 13cm | 120-130 mm | Doors (budget cars) |
| 6.5" | 16-17 cm | 160-165 mm | Doors (basic standard) |
| 6x9" | 15x23 cm | Oval 150x220 mm | Back shelf, doors. |
| 8" | 20 cm | 180-200 mm | Back shelf, subwoofers. |
Oval speakers 6x9 They need a special approach. When installing them in a round hole, serious improvements will be required, and when installing an oval in an oval, it is important not to confuse the orientation (vertically or horizontally). There are also many non-standard sizes, especially in Japanese-made cars, where diameters can be tied to specific series of models.
Nuances of oval dynamics
Oval speakers often have an asymmetric basket, making them difficult to fit into round holes even using slot rings. In addition, their magnetic system can be shifted relative to the center, which requires additional space in the depth on one side.
Installation problems and ways to solve them
Even knowing, How to measure the size of the speakerYou may encounter a situation where the perfectly diameterd speaker does not stand in place. The most common problem is a conflict with the window lifting mechanism. In this case, the only way out is to manufacture podium Or a sling ring. It carries the speaker outwards, increasing the distance to the internal mechanisms of the door.
Another common problem is the insufficient depth of the staff place. If the magnet rests, you can try to carefully cut out some of the metal or plastic behind the speaker, but only if there are no vital nodes. Be extremely careful with wiring: wire harnesses often pass in the doors, damage to which will lead to inoperability of locks or windows. Always check the back before starting work.
⚠️ Attention: Never drill holes in areas where the power elements of the body or fuel lines pass (although there are usually no doors, but the frame reinforcement can be). Use a flashlight to check the back of the panel.
If the speaker is too large in external diameter, but fits the fastener, you can consider the installation option without an external decorative frame, if the design of the speaker allows it. Sometimes it helps to trim the plastic grille of the door or replace the standard grilles with universal ones that have a larger internal diameter. The main thing is to ensure the rigidity of the attachment so that parasitic vibrations do not occur on the bass.
Choosing acoustics: what to look for after measurements
Once all the sizes are recorded, the selection stage begins. When searching in directories, use filtered values: if you have a 160mm hole, a 165mm speaker may require a scavenging or transition ring, which is normal. However, the speaker 170 mm may no longer fit. Pay attention to the parameter. Xmax (linear stroke) - the larger it is, the deeper a seat may be required for the diffuser to run.
Sensitivity and power are also important. If you don’t plan on installing an external amplifier, choose speakers with high sensitivity (from 90-92 dB). If you plan to build a high-quality system, it is better to take speakers with a power reserve and lower sensitivity, but better linearity of the frequency. Do not forget about the diffuser material: paper gives a warm sound, but is afraid of moisture, and polypropylene or Kevlar are more durable in the conditions of the Russian winter.
Proper measurement of depth and diameter is 90% of the success of the installation. Don’t ignore millimeters, they determine whether the sound will be clean or the speaker will fail in a week.
In conclusion, a competent approach to measurements can avoid 99% of installation problems. Don’t be lazy to remove the door map completely – it will give you a complete picture of the space. Remember that quality sound starts with the right geometry. If you doubt your abilities or the size is critically small, it is better to contact professionals who have experience with specific brands of cars and know the typical “sickness” of landing acoustics.
Can you install a speaker larger than the regular one?
Yes, it is possible, but it will require the manufacture of a parcel podium and possibly the modification of the door map. The main condition is the presence of free volume inside the door and the absence of conflict with the window. Often increase the size from 13 cm to 16 cm.
What if the speaker is deeper than the available space?
The two options are either to cut out part of the interior wall of the door (if it is safe there), or to use a speaker with a smaller magnet. In extreme cases, a remote podium is made, which is put on top of the door trim, but this changes the appearance of the cabin.
Do I need to handle the door opening before installation?
Preferably. The hole should be smeared with vibration insulation material, and the speaker himself should be planted on a sealant or a special sealing tape. This will improve sound and protect the contacts from moisture and oxidation.
How to find out the size of the speaker without removing, by marking?
Sometimes the size is indicated on the back sticker (e.g. 160 mm or 6.5). However, relying on this is risky, as the previous owner could install a non-standard model through the adapter. Measurement of the physical hole is more reliable.