Speakers for a 12-inch subwoofer occupy an intermediate position between small acoustic radiators and the most powerful devices with a diameter of 18-20 inches. Speakers of 6-8 inches allow you to get quite powerful sound, but some, especially strong bass, will not stand out against the background of other instruments. Drivers with a diameter of 46 centimeters are the basis of a super-powerful low-frequency system, which not everyone needs, so 12-inch speakers are considered the golden mean. The box for a 12-inch subwoofer can be made according to any design.
The easiest one to make with your own hands is a closed type column. This means that only one hole is cut into the side of the box for the speaker. The box for a 12-inch subwoofer must be made of such material as to completely eliminate vibration and rattling when reproducing low frequencies.
Enclosed box for 12" subwoofer
The volume of a box for a 12-inch subwoofer should be in the range of 25-38 liters. This applies to a closed design. The presented version of the design of a closed-type low-frequency speaker is made of pressed MDF material with a thickness of 18-20 mm. The column can be made from moisture-resistant multi-layer plywood. In this case, it is necessary to take into account its resonant properties. Powerful and deep bass can cause a “ringing” in a plywood box, which will ruin the entire sound picture. To avoid this, plywood boxes are equipped with additional stiffening ribs in the form of wooden blocks. They are screwed with self-tapping screws from the inside of the body. Before this, the bars are coated with Moment glue. The dimensions of the box for subwoofer 12 are based on a volume of 37 liters. The depth of the low-frequency speaker does not exceed 37 centimeters. With a width of 34 centimeters, the device will easily fit into the trunk of any car.
Types of subwoofers
When figuring out how to make a subwoofer, it is necessary to evaluate the properties of the main types of these devices. The user can choose among the following varieties:
- Active subwoofer.
- Passive type models.
Active designs are available with an amplifier and crossover, which guarantees good sound with suppression of the high-frequency range. Such models can work with any sources.
Samples of the second group are not equipped with amplification units, and are connected to the standard radio. The disadvantage of a passive device is that the channels are fully loaded, which degrades the quality of the reproduced sound.
Depending on the design features, the following types of boxes are distinguished: open and closed boxes (CL). The former are built into the finishing elements of the interior, and the latter are made in the form of independent boxes, inside of which a speaker with a low-frequency range is installed.
Calculation of a box for a 12-inch subwoofer
The work of making a box for a low-frequency sound system begins with choosing a speaker. Low-frequency speakers for a car subwoofer are produced by many companies. The cost of some models reaches 100,000 rubles. However, a good bass driver can be purchased for less money, and the technical characteristics of a powerful driver ensure high quality bass reproduction.
- SWAT SW-M12
- ESX SX1240
- Audison AV 12
The first model has a cellulose diffuser and provides a uniform frequency band in the range of 27-300 Hz. Rated power 200 watts at a resonance frequency of 40 Hz. To install such a speaker, you will need a 12-inch subwoofer box with a volume of 60.5 liters. The SX1240 loudspeaker features an increased power output of 500 watts, powered by dual aluminum coils and strong cobalt-samarium magnets. The stroke of the polypropylene diffuser on a rubber suspension can reach 35 mm. Such power will require a housing for a 12-inch subwoofer with a volume of 82 liters.
The Audison AV12 delivers 500 watts of power with a sensitivity of 91 dB. The speaker system diffuser is made of cellulose with cotton fiber additives. In addition to the main air duct, the speaker provides additional cooling in the form of several holes. The speaker has an extended bandwidth that is linear from 27 to 1000 Hz, so to use it as a subwoofer you need to use a mid-cut filter. This design allows you to use a smaller 12" subwoofer box than the standard for 30cm speakers.
Which speaker to choose
To make a subwoofer from a regular speaker, you need to take a number of parameters into account, since they affect the size of the future speaker box. Often, inexperienced drivers make a mistake and choose a device based on power. However, these values only indicate the load capacity that the speaker can handle for an hour or a few seconds. Therefore, a powerful device does not guarantee good and clear sound.
When choosing a product, you first need to evaluate the properties of the diffuser. To get less distortion at peak volume, it is better to use large designs with a small amplitude of vibration.
Since the diffuser is subject to increased air resistance, the material from which it is made must be strong and reliable. Paper products are only suitable for “sound-in” speakers. Models based on polypropylene are sensitive to temperature changes and have minimal rigidity, which is why they are used in budget car acoustics. The best solution is considered to be carbon fiber and Kevlar.
As for metal acoustic systems, they provide precise sound production with intense resonance. However, these features only appeal to some users.
When choosing a speaker, its sensitivity is also taken into account. The characteristics can be assessed by the dimensions and power of the magnetic element.
You should also pay attention to the resonance frequency.
Box for subwoofer 12 inches drawing
The design of the box for a 12 subwoofer depends on the design of the sound system. When using speakers of a smaller diameter, it is not always possible to implement a bass reflex design, while a 12-inch speaker is suitable for this. How to calculate a box for a 12-inch subwoofer with a bass reflex.
The bass reflex can be slotted, as shown in the drawing, or in the form of a pipe. The first design is practically not adjustable, so after the subwoofer is manufactured it will be difficult to change its acoustic characteristics. In household acoustic speakers, the flow and efficiency of the air flow can be adjusted by placing pieces of foam rubber in the acoustic box. This is more difficult to do with subwoofers. The dimensions of a 12-inch subwoofer in centimeters are indicated in the drawing and are determined by the characteristics of the loudspeaker used, therefore most bass reflex box circuits are designed for a specific speaker model. The main element of the bass reflex in a subwoofer is the port. This is the part of the structure in which the phase of the audio signal is rotated. The quality of the entire sound system depends on the accurate calculation of the port.
What to make from
To make a subwoofer with your own hands, it is important to take care of the materials for its creation. First of all, you should prepare the following:
- Speakers. When choosing a speaker, you should evaluate its technical parameters: they must correspond to the capabilities of the car radio. If a new part is purchased, then all the characteristics will be indicated on the packaging or in the package insert.
- MDF sheets. Enclosures for subwoofers are also made from plywood, chipboard and fiberboard. The type of material is selected taking into account the dimensions of the future structure.
- Acoustic cable.
- Sealing compound or PVA glue.
- Fastening elements. They use self-tapping screws, since nails are prohibited for such work.
- Epoxy resin.
- Paint and varnish product.
Calculation of housing for a 12-inch subwoofer
First of all, you need to choose the type of enclosure. What volume is needed for a 12 subwoofer. For a 30 cm loudspeaker, the volume of a closed box should be about 32 liters, but not more than 40. For a bass reflex design, twice the volume will be required. A small box for subwoofer 12 can be made from MDF. The material must be chosen unpainted and without plastic coating. The minimum volume of a closed box for a subwoofer is 22 liters. If wooden elements are cut out by hand, then during assembly the seams must be coated with any “liquid nails”. When cutting the material by hand, the seams are uneven, and the filler will seal the joints. When cutting on a machine, this is not necessary. The correct box for a 12-inch subwoofer will only be obtained if all dimensions are strictly observed.
How to calculate a box for a subwoofer 12. To calculate the volume, there is a simple “school” formula, where the volume is equal to the product of the length, width and height of a rectangular box or V=L*X*Y, where L, X and Y height are width and depth. Since the subwoofer is most often installed in the trunk, knowing the maximum allowable height and the required volume for a particular speaker, it is easy to calculate the width of the front wall and the depth of the front wall for a 12-inch subwoofer. You can make a case for a 12-inch subwoofer with an inclined front wall, but its calculation will be more complex. To perform all calculations related to the design of a subwoofer, there are online programs. A convenient calculator is Subbox.pro. The program offers several subwoofer design options, including closed box, slot or tubular bass reflex. Unlike the online program, BlauBox and PerfectBox 4.5 need to be downloaded. These products are universal and accurate, but do not have a Russian-language interface, and it will be difficult for an untrained amateur to understand them.
Possible malfunctions and repairs
Do-it-yourself subwoofer repair may be required if its elements are mechanically damaged. If the coil encounters an audio frequency that exceeds the permissible limit, it may fail. A similar problem occurs when listening to music at maximum gain, which causes the cone to rupture. Repairing the unit is quite simple, because it can be replaced with a new one.
Restoring the functionality of a diffuser or coil is a difficult task that will require a lot of time and effort, and every specialist who has repaired such a unit will recommend replacing it.
Overheating of the internal parts of the subwoofer often leads to breakdown. The problem is related to the contamination of the internal space with dust and technical debris. First, you need to evaluate the voltage in the power supply using a tester - if it is missing, you will have to replace the power supply.
When inspecting the interior, you may find swollen capacitors or blackened windings. Damaged elements need to be desoldered with a soldering iron and replaced with new, serviceable ones.
Speaker repair begins with disassembling and dismantling the subwoofer head. All actions must be performed without haste, since sudden movements can damage the reel sleeve.
Subwoofer box 12 inches fi
After the box for the 12-inch subwoofer is made with your own hands, you can begin the final finishing of the case. A slotted bass reflex is a rectangular volume, limited by planes. In the inner corners of the structure, turbulence of air flows will occur, which negatively affects the inversion of the phase of the sound signal and the quality of playback. To avoid this, you need to smooth out all the internal corners of the structure by adding a vertical wooden strip to each corner. The planks do not bear any mechanical load, so it is not necessary to install them with self-tapping screws, but it is better to use Moment glue.
An important thing when setting up a 12-inch subwoofer is its location in the luggage compartment. The bass reflex port should not be close to the obstacle, but it should not be located too far either. A distance of 20-25 cm can be considered optimal.
How to install a subwoofer
Installing a subwoofer box in a car with your own hands is not a difficult task. However, for successful installation you need to have some skills and tools. In addition to placing the subwoofer and amplifier, you should take care of the following related devices:
- Circuit breakers.
- Wiring.
- Capacitors.
- Plastic clamps.
- Spanners.
- Electrical tape and wire cutters.
After choosing the optimal location for installing the subwoofer, you need to make sure that it can cope with resonances from the device. It is not allowed to place the box on fragile machine structures.
The wires are connected according to the following diagram:
- First you need to connect the cable to the amplifier.
- Next, the amplification unit is connected to the car radio.
- A cable with a positive value is wrapped in corrugation to protect it from deformation.
- The fuse is fixed on the same wire, maintaining a minimum distance between the batteries.
Before starting a homemade sub, it is important to check whether the battery is disconnected. This rule will allow you to protect yourself from electric shock and avoid damage to the radio.
Drawing of a box for 2 12 subwoofers
The box for two 12 subwoofers can be made in different versions. The simplest option is two independent volumes, not interconnected, where each speaker has its own bass reflex. A more complex design would be a box with two speakers and a common air space. Such a case should also have two bass reflexes, and they should be configured differently. It is better to equip a box for 2 12-inch subwoofers with two tubular bass reflexes. In this case, the adjustment comes down to changing the length of the pipe. To do this, the tubular bass reflex has an internal segment that can be moved inside the main cylinder, changing its length.
