To properly connect a subwoofer in a car, you need to solve several problems. First, the choice of low-frequency channel power is determined. If the car owner expects a comfortable sound picture in the cabin, then the output power of the system should not exceed 80-100 watts. In this case, the speaker can be placed on the shelf behind the back of the rear seat. With a higher output power, to obtain maximum sound pressure, the low-frequency speaker is placed in the luggage compartment of the car. Connecting an active subwoofer to a car includes supplying power to the built-in low-frequency amplifier and connecting the input terminals to the radio.
Connecting an active subwoofer to a car
Connecting a subwoofer to a car begins with preparing the connecting cables to supply power voltage and sound signal. The low-frequency system with a built-in amplifier is a design completely ready for installation. On the back or side wall of the case there are terminals for connecting the supply voltage and the output of the music center. Special cables are used to connect the subwoofer to the car. The power wire must be copper and stranded, and its cross-section is determined based on the output power of the amplifier. To determine the material, just look at the cable cut. Aluminum and copper wires differ in the color of the metal. If the ends of the cable are pressed into lugs, then you can determine a good copper wire by weight. A wire made of copper-plated aluminum is much lighter. You can connect the battery to the ULF using the power cables that are included in the set of wires for car audio, or you can purchase a piece of wire of the required length. To supply power to the amplifier, a high-quality welding cable of the KG-25 type is often used.
Bass is out!
When choosing a subwoofer, you should also consider what connections your system's amplifier has. If it does not have a preamplifier output, then you must definitely look for a model equipped with high-level inputs - not everyone has them. But almost every sub has linear inputs.
The LFE input is useful for connecting to an AV receiver or cinema processor. It is supplied with a low-frequency signal specially recorded in the soundtrack, which these devices separate into a separate channel during decoding.
If your speakers are in a minimalist system with a single electronic component, such as a network or stereo receiver, then it may well be that it has a subwoofer output.
How to connect a subwoofer to a car
What you need to connect a subwoofer in a car. In addition to tools, you will need the following products:
- Power cable
- Interblock shielded wire with RCA connectors (Tulip)
- Bulb with fuse
- Nut lugs for power cable
- Plastic bushings and ties
The connection diagram for an active subwoofer is not difficult. The red wire supplies “+” power from the car battery to the corresponding terminal of the low-frequency amplifier. To prevent overheating of the cable from causing the insulation to burn, a fuse is provided in this circuit. It protects the cable, not the amplifier. The ULF power supply circuit has its own fuse. According to the installation rules, the bulb with the fuse should be no further than 15-20 cm from the battery. To connect the power cable to the battery, a tip under the nut is soldered onto its end and plastic heat shrink is put on. The negative power terminal of the amplifier is connected to vehicle ground. To do this, you can use any bolt with a washer. If the power of the low-frequency channel exceeds 800 watts, it is recommended not to connect the negative of the amplifier to the vehicle ground, but to lay a separate cable from the battery. Thus, the connection between the subwoofer in the car and the battery will go through two wires.
Where to install
For some motorists, installing acoustic equipment can be a big problem. The matter concerns both the size of the device itself and the car model.
Hatchback and minivan. In cars with this type of body, you can easily find space even to accommodate a large system. This is explained by the good trunk capacity.
Sedans. The trunk in sedans has a smaller volume, so there is not always room there to install a subwoofer. The problem can be solved by installing speakers in the armrests or on the rear shelf.
Cabriolet. In such a body, it is most difficult to connect a subwoofer to the car, since space is at a premium here. In this case, it is better to choose bandpass type acoustics or FC cabinets equipped with a bass reflex.
How to properly connect a subwoofer in a car
When laying all wires, from the engine compartment with the battery to the installation site of the low-frequency speaker, you must follow the installation rules. Cables are passed through existing technological holes. If this is difficult or inconvenient, you can drill the holes yourself. Protective rubber bushings must be installed at the intersection points between cables and metal surfaces. The most reliable way is to lay the wires in a corrugated plastic sleeve. The wiring must be firmly fixed, so plastic ties are used to secure it. When installing a subwoofer in a car, in addition to the signal wire and power supply cable, a single unshielded control line wire is laid between the car radio and the active speaker.
When you turn on the power to the radio, the potential from this wire turns on the power supply to the active system. Often this wire is not connected, and a separate toggle switch is used to supply voltage to the amplifier. Connecting an active subwoofer in a car without a fuse is not allowed, since about 70% of all fires in a car occurs due to a short circuit in the unprotected power wires of the speaker systems. The fuse must be installed in the engine compartment next to the battery. With a cable cross-section of up to 10 mm2, it is permissible to install a fuse for a current of no more than 60 A. With a cross-section of 20 mm2, a 100 A fuse is required. A fuse for a lower current can be installed, but a fuse for a higher current cannot be installed, as this can lead to a fire.
Required tools and materials
Before connecting a passive subwoofer (without an amplifier) to your tape recorder, you need to make some preparations. They consist of finding or purchasing the tools you will need while working. In addition, it is worth buying quality materials.
Items you will need to connect:
- Plastic bumpers (necessary to hold the subwoofer frame in the luggage compartment of the car);
- speaker cables for wiring;
- plugs of different sizes (needed to connect the speaker system to the car stereo);
- flexible cable ties to protect cable connections from accidental contact with parts of the device;
- corrugated pipe to protect laid wires;
- PVC insulating tape (PVC);
- plastic screwdriver for easy removal of car trim;
- a side cutter that will help you cut the wires to the desired length.
Installing a subwoofer in a car
The subwoofer in the car is connected to the sound source using an interconnect cable. Here a lot depends on the type of car radio. Some models are equipped with a separate connector for connecting a low-frequency channel. This connector is marked “SUB”, “Sub. Out" or similar combinations of characters. In this case, a shielded cable with “Tulip” connectors at the ends is used to connect the active low-frequency system. Another connection option involves using connectors to connect rear speakers. Connecting an active subwoofer to a car is done using a bridge circuit. Typically, standard car radios or stereos are equipped with standard connectors with blade contacts. The block consists of three parts. To connect sound speakers, connectors “B” and “C” are used.
The pinout of the contacts of block “B” on the speakers is as follows:
- B1 – rear right “+”
- AT 2 -" - " - " - " - " - "-"
- B3 – front right “+”
- AT 4 - " - " - " - " - " - "-"
- B5 – front left “+”
- AT 6 - " - " - " - " - " - "-"
- B7 – rear left “+”
- AT 8 - " - " - " - " - " - "-"
Signals from the linear output of the radio amplifier are output to the contacts of block “C”.
- C1, C2 – left and right rear speakers
- C4, C5 – left and right front speakers
- C3 – body (ground)
- C6 – remote power up of the amplifier
There are two ways to connect an active subwoofer to a car. In one case, the contacts of connector “B” are used, intended for rear speakers placed in the car interior. You can connect an active subwoofer to a car from block “C” using a special adapter with RCA connectors. If the sub in the car is installed in the luggage compartment, you will need to extend the wires.
Does size matter?
Subwoofers are equipped with drivers of various diameters, usually 8, 10 and 12 inches; The dimensions of the cases also depend on this. The larger the driver, the deeper bass it promises to create, but it's wise to take into account the size of the room where it will be working. In a small one, a large one will take up a lot of space, and this is perhaps the only contraindication for purchasing it, apart from the price. A large speaker will work with less load, and therefore with less distortion, creating a sound loud enough for such a room.
It is impossible to listen to a subwoofer in a hi-fi salon - in isolation from your stereo system and room, so you should rely on reviews in specialized publications, customer reviews or advice from experienced sellers.
How to properly connect a subwoofer to a car
An active subwoofer connection in a car may require a channel combiner that mixes the right and left signals while limiting the level to safely feed the signal to the amplifier input. The device can be purchased at a specialized store or made independently. The diagram for connecting an active subwoofer to a car contains a minimum number of parts and does not require configuration or adjustment.
The circuit uses three constant resistors, which are soldered directly to the connector. To avoid interference and impulse noise, the connection between the subwoofer and the car radio is made with an insulated shielded wire.
In addition to the active low-frequency system, you can install a passive subwoofer in the car. It is a box (box) in which a powerful electrodynamic head is installed. The passive system box can be assembled using a closed circuit or with an acoustic bass reflex. If the speaker is designed for a power of 15-25 watts, it can be connected directly to the output of the car radio. To obtain high output power, such a speaker is usually used in conjunction with a low-frequency amplifier. The car ULF unit is installed next to the low-frequency speaker. The usual location is the luggage compartment. Power to the amplifier is organized according to the same rules as to the active device.
Significant frequencies
Experiments have shown that sound waves accessible to the human auditory system have frequencies from 20 Hz to 20 kHz. These figures are approximate, since all people are different, and the physiology of the same person changes with age.
This range is usually divided into three main parts: low, medium and high frequencies. The most important in terms of information transfer are the second and lower sections of the third; Therefore, telephony uses a band from 300 Hz to 3400 Hz. “Pure sine” at 3 kHz is a squeak, but such frequencies are very important for hearing, since they ensure speech intelligibility.
The fundamental tones of voices and many instruments lie in the range from 80 Hz to approximately 500 Hz, so bookshelf speakers, which are generally capable of producing sound from 60-80 Hz and up to 20 kHz, are very good devices for playing music and singing, capable convey most of the details and nuances.
So what does this very small piece of the audio spectrum from 20 to 60 Hz provide? The answer is simple: realism and authenticity of the musical scene, and it also provides full reproduction of the sound of some particularly bass instruments, for example, a piano, whose lower note has a fundamental frequency of 27 Hz; for the double bass and kick drum, by the way, it is 40 Hz.
Modern recordings also store information about the acoustics of the hall in which they were performed, thanks to the sound recorded in them and the attenuation of standing waves in it. And if this is a studio album rich in electronic effects, then so are all the low-frequency ideas of the sound engineers.
Correct connection of an active subwoofer in a car
Often, during the operation of a powerful active system, at high volume levels, a short-term decrease in the sound level occurs, up to complete loss. This is due to the fact that at the peak power of the amplifier, the current consumption increases greatly, and the car battery cannot provide adequate power. To avoid this effect, the subwoofer in the car is connected in parallel with a large capacitor. With this method of organizing power supply to the device, the capacitor plays the role of an additional power source. It stores electrical energy and, at the moment of excessive consumption, supplies it to the amplifier’s power circuit. The capacity of such a capacitor is usually 1-2 farads.
In addition to connecting an active subwoofer in a car, the same principle is used to supply power to a low-frequency amplifier for a passive speaker system. All electrical connections are made with multi-core copper cable that can withstand high current with minimal losses. To avoid voltage drop in the wire, the distance between the positive contact of the capacitor and the “+” power supply of the amplifier should not exceed 15-25 cm. The capacitor itself is mounted as close as possible to the low-frequency amplifier. In order to limit the entry of the high-frequency part of the audio range, a crossover filter with a certain cutoff frequency is turned on at the input of the speaker system. A passive LC filter “cuts” frequencies above 180-250 Hz.
Useful tips
To properly connect a passive subwoofer to a car, you must take into account the recommendations of car service professionals. They will help to avoid various difficulties and maximize the quality of work for a novice user.
- When connecting a capacitor, always pay attention to the polarity. Otherwise, the device may not perform its functions properly or may be damaged.
- After connecting two devices, check the quality of the contact. To do this, a visual inspection is carried out and possible defects are identified. If kinks or damage to the protective layer are detected, the problem area should be insulated.
- The fuse used must match all parameters of the connected device.
- Car owners often face the problem of mismatch between various characteristics of the car radio and subwoofer (for example, frequency response). In this case, it is recommended to make adjustments not on the car stereo system, but on the subwoofer control panel.
- All work may only be carried out with the engine turned off. Also turn off all electrical devices.
- When installing a speaker system, it is recommended to use only high-quality cables. Failure to follow this recommendation leads to rapid failure and, as a consequence, to various problems with the operation of the device.
Connecting a subwoofer to a stereo system without an amplifier is considered a difficult task. To perform it, you must carefully follow the correct procedure and avoid the slightest inaccuracies. Only then will the device work well and delight the vehicle owner.
In the discussion: amplifier for Ural As-d12.3, just a couple of questions.
Good afternoon Yesterday I bought myself a ural as-d12.3 subwoofer, and now the choice is up to the amplifier. Tell me which one to take? So far I've settled on Mystery 1.300, but it seems to be too weak for this subwoofer. Or not? I also looked at Kicx kap 27, but it was very expensive. Help me make the right choice.
