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.
Soundproofing surface
Soundproofing the box from the inside will increase the efficiency indicators. You can use various materials, both liquid and sheet.
Liquid soundproofing solutions are applied to the entire internal surface with a thickness of 1-2 mm, including the bass-reflex air duct.
Sheet noise insulation can be attached using PVA glue, also along the entire inner surface of the case.
After treating the box with soundproofing materials, you can insert the subwoofer head, screwing it tightly and fastening all the walls of the box.
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.
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.
Cutting parts
So, you have decided on the shape for the sub box and you have a drawing.
Mark the sheet according to the parts and cut according to the marked dimensions. Use a disk with a large number of teeth; the smaller the tooth size of a circular saw blade, the fewer chips you will get, and their size will be insignificant.
If you use a manual circular saw and your hand is not full, it is better to use a guide so as not to accidentally “fill up” the cut.
It is better to do this work together, since it is quite inconvenient for one person to turn large sheets and hold them while working.
Below is a good video from Rockford Fosgate, albeit in English, but everything is clear here without translation - choosing the shape of the body, lining up the parts, cutting.
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.
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.
What's the result?
As you can see, the decision to make a housing for a subwoofer in a car with your own hands will require certain skills and tools. However, if you do everything correctly and use good quality materials, you can get a fairly powerful sub with good sound.
Finally, we note that after connecting the subwoofer, you also need to configure it. Only after proper adjustment and tuning of the subwoofer will the sound “reveal” to its fullest, which will allow you to fully customize the car’s acoustic system in the future.
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An HF box or quarter-wave resonator is a hollow box made of any furniture material. The design is used for a subwoofer and allows for deeper sound with a harmonious spectrum. Such branded devices are quite expensive, but the box can be assembled independently from scrap materials. This is exactly what we will discuss in our review.
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.
