Creating an audio system for the home with your own hands is an exciting project that allows you not only to save your budget, but also to get a unique sound. Many motorists are faced with a situation where after replacing the standard sound remain quality. car-speakersThrowing away that just doesn't lift your hand. Using these components to assemble stationary acoustics is a great way to give them a second life.
The main difference between automotive acoustics and home acoustics lies in the design of speakers and requirements for reinforcement. Coaxial Component systems designed for the interior of cars often have low resistance and high sensitivity, which requires a special approach to the assembly of crossovers and the choice of amplifier. However, with a competent calculation of the volume of the case, the sound can surpass many budget store solutions.
In this article, we will discuss all the stages of turning car heads into a full-fledged home Hi-Fi system. You will learn about the nuances of acoustic design, connectivity features and customization methods that will unlock the potential of your speakers in a living room.
Features of car speakers at home
The first step to success is understanding the physics of the process. Car speakers are designed to work in specific conditions: small cabin volume, high humidity and vibrations. Theirs. goodness (Qts) are often lower than those of specialized home speakers, which dictates certain design requirements. If you just connect such a speaker to an amplifier without a body, you will hardly hear bass.
An important parameter is impedance. Standard home speakers usually have a resistance of 4, 6 or 8 Ohms, whereas automotive speakers are often produced with a resistance of 4, 6 or 8 Ohms. 2 ohm Or even 1 ohm per channel. This is done to get maximum power from the onboard 12 volts network. When connected to a home amplifier with a calculation of 4-8 Ohms, such a load can cause overheating and protection operation or the device fails.
⚠️ Attention: Before assembly, be sure to measure the resistance of the speaker coil with a multimeter. Connecting 2-ohm speakers to an amplifier designed for a minimum of 4 ohms will lead to the combustion of the output cascade.
Also, it is worth considering the lack of built-in crossovers in many models. In a car, frequency separation often takes over the head unit, so for high-quality home acoustics you will need to assemble or buy an external one. frequency-fiber. Without this, high frequencies can overload the low-frequency speaker, and mid-frequency speakers will wheez from bass.
Car speakers have low resistance and require careful selection of an amplifier capable of working with a load of 2-4 Ohms without overheating.
Required tools and materials for assembly
To implement the project, you will need not only the speakers themselves, but also a number of materials for creating a housing and switching. The build quality directly affects the final sound, so you should not save on the materials of the body. The basis will be a sheet material with high density, not resonating at low frequencies.
Here is a list of basic equipment that needs to be prepared before work begins:
- 🛠️ MDF sheets or plywoods of 16 mm thick for the shell walls.
- 🔌 Copper acoustic cable with a cross section of at least 2.5 mm2 for internal wiring.
- 🔨 Glue gun or carpenter glue PVA for sealing joints.
- 📏 Roulette, coal and pencil for accurate marking of details.
Pay special attention to terminals (plumes) for connecting the wire. Car speakers often have non-standard seats, so transition rings may be required to securely fix them in the front of the body. They can also be made from MDF residues or plywood.
☑️ Checking assembly readiness
Calculation and design of acoustic design
The most critical step is the calculation of the volume of the body. Automotive speakers often require a closed box (CJ) or phase inverter (PI) of a strictly defined cast. Parameters Thila-Smola T/S parameters are the speaker’s passport data, which indicate how much air it needs to work properly. You can find them in the technical documentation of the model or on the manufacturer's website.
For beginners, it is easiest to start with a closed design. It is less demanding on the accuracy of calculations and forgives errors in volume. The phase inverter gives a deeper bass, but requires fine tuning of the length and diameter of the pipe. An error in the FI calculations will lead to a “buzzing” bass without legibility.
Below is a table of approximate volumes of housings for speakers of different diameters, but remember that this is an averaged data:
| Dynamics diameter | Type of design | Recommended volume (litres) | Frequency setting (Hz) |
|---|---|---|---|
| 10 cm (4 inches) | Closed drawer | 2 - 4 l | 60 - 80 |
| 13 cm (5.25 in) | Closed drawer | 5 - 8 l | 50 - 70 |
| 16 cm (6.5 in) | Phasoinverter | 12 - 18 l | 40 - 50 |
| 20 cm (8 in) | Phasoinverter | 25 - 35 l | 35 - 45 |
When designing, take into account the internal space, which will be occupied by the speaker, crossover and mounting elements. The usable volume should be clean, so always subtract the wall thickness and internal volume of components from the overall dimensions.
Formula for calculating the phase inverter
For the precise calculation of the length of the pipe of the phase inverter, the formula L = (2350) is used. D^2) / (Fb^2 V) - 0.732 * D, where D is the diameter of the pipe, Fb is the frequency of adjustment, V is the volume of the shell. It is better to use online calculators, as manually counting is long and you can make a mistake.
Shell manufacturing and acoustic processing
The manufacturing process begins with cutting the material. Use a circular saw or jigsaw with a saw for clean cutting. All the internal surfaces of the future body must be thoroughly smeared with glue, and after assembly, all joints and slits should be filled with thermal glue or sealant. Tightness A key requirement for a closed drawer; any fistula of air will spoil the bass.
To reduce the resonances of the walls, the inside of the body is pasted with vibration insulation material or felt. This absorbs the standing waves inside the box, making the sound cleaner. If you make a phase inverter, install the pipe so that its output is not blocked by internal elements.
Appearance also matters. The body can be covered with carpet (car fabric), pasted with a self-adhesive film under a tree or painted. Karpet hides small build flaws and is easily glued to PVA, making it an ideal choice for DIY projects.
When gluing the body, use rods to tightly press the parts until the glue is completely dry. This will ensure maximum rigidity of the structure.
Connection scheme and assembly of the crossover
Connecting car speakers to a home system requires an understanding of electrical circuits. If you have component acoustics (a separate RF speaker and tweeter), you definitely need a crossover. A simple serial connection will cause high frequencies to go to the bass, and low frequencies can damage the squeaker.
The connection circuit looks like this: the signal from the amplifier goes to the input of the crossover, which divides the frequencies. The RF channel goes to midbass, the RF channel goes to Twitter. For coaxial acoustics (where the squeaker is built into the center of the speaker), the crossover is already built in, but it is often primitive (just a capacitor). For high-quality sound, it is better to replace it with an external one.
When soldering, use high-quality solder and flux. Screws in acoustics are unacceptable - they oxidize and create interference. Observe polarity: “plus” the amplifier to “plus” the speaker. Confused polarity leads to phase distortions, when the speakers begin to work “in antiphase”, extinguishing the bass.
⚠️ Attention: The power of resistors and capacitors in the crossover should be calculated with reserve. Use components with a power of at least 10-20 watts so that they do not burn up when playing loudly.
Selection of amplifier and coordination
The final stage is the choice of the amplifier. As mentioned earlier, car speakers often have low resistance. You need an amplifier that runs at 2 or 4 ohms. Old Soviet or modern Chinese Class D amplifiers (e.g., chip-based) TPA3116 or TDA7498) will do an excellent job of doing so.
The power of the amplifier shall be comparable to the rated power of the speakers. It is better to have a stock of 20-30% than to work at the limit of possibilities. The work of the amplifier in the clipping (overload) mode is guaranteed to burn the speaker coil. The power supply of the amplifier must be powerful enough to give the required current without voltage drawdowns.
To test the system, collect all the components, but do not fix them dead. Turn on the music at medium volume and listen. If the bass is buzzing, reduce the volume of the body or seal the phase inverter. If you hear a ringing, add internal vibration isolation.
Correct coordination of resistance of speakers and capabilities of the amplifier is the key to the durability of your homemade acoustic system.
Can I use a car subwoofer without an amplifier?
No, you can't. Subwoofer heads have very low resistance and require powerful amplification of low frequencies. Connecting directly to the signal source (phone, PC) will not give sound, and to the output of active acoustics can lead to overload.
Which glue is best used for MDF?
The best option is carpentry PVA glue (D3 or D4) in combination with screws. For rapid fixation and sealing of the cracks, thermal glue or acrylic sealant is excellent.
Why do speakers hoarse at high volume?
The main reasons: insufficient volume of the body (the speaker rests on the speed limit), overload of the amplifier (clipping) or mechanical restriction of the diffuser (emphasis on the magnetic system).