How to connect a two-channel amplifier to a subwoofer

For self-installation, it will be enough to purchase the necessary components and familiarize yourself with possible connection diagrams, and you can save on visiting a car service center. If a passive design is used, each of the system devices can be selected according to the specified characteristics. If it is necessary for the subwoofer and the radio to be turned on simultaneously, then use the corresponding positive wire. How to connect two subwoofers of 2 and 4 ohms. If your amplifier or active subwoofer does not have such an input, what should you do in this case? How to connect a subwoofer (series and parallel connection of speakers) The LPF knob is a low-pass filter. Now you just need to see at what resistance your amplifier produces how many watts, and connect.

Then we pass the wires together with the power cable through the interior. If you have two similar speakers, you can simply connect them in series or parallel and get the desired impedance.

When connected in parallel, the resistance will be 1.3 Ohms, and when connected in series - 6 Ohms. Connecting two 2 Ohm subwoofers. Acoustic equipment in a car must be mounted conveniently and securely. On domestic cars it may be missing, as well as the hole itself.

Naturally, the resistance of the coils must correspond to the operating load of the amplifier in a bridge connection and the GAIN controls must be at the same level. Parallel and serial subwoofer connection

Scheme development

The connection diagram depends on the number of amplifier inputs, the location and power of the speakers, and the presence or absence of a subwoofer.

Power amplifiers are:

• two-channel, designed to connect only a pair of speakers;
• four-, used to connect two speakers and a subwoofer or four (there is also a daisy chain connection scheme for four speakers and a subwoofer);
• six-, used for a standard connection of four pieces and a subwoofer.

It is also important to consider the rated power (W, W) and the resistance of all connected equipment (Ohm). They can be found either on device labels or in technical documents. The total connection resistance should not exceed the maximum permissible standard.

There are three ways to connect speakers to an amplifier.

1. Sequentially—speakers of the same type are alternately connected to each other and then to the device.
2. Parallel - performed by a polar connection directly to the outputs of the device, while their resistance and power may differ.
3. Series-parallel - used in cases where it is necessary to connect two columns with the same resistance and additional ones with other parameters.

How to set up a subwoofer in a car

Setting up the subwoofer should be done while designing the speaker box. The main role here is played by the parameters of the speaker, which determine the boundaries of its functioning in the acoustic design. If you have a dilemma about how to set up a sub in a bass reflex enclosure, it is recommended to install the port both higher and lower, depending on your favorite type of music. And for a device in a factory frame, connecting a subwoofer with a bridge is limited, but with a well-chosen circuit it is more than possible to achieve good sound.

As a backup option, use special applications for your phone (Subwoofer Bass).

Setting up the LPF lowpassfilter filter

Nowadays, a classic LPF filter is almost always present on a subwoofer. This type of filter allows you to select the threshold at which high frequencies begin to be blocked, which allows you to simply mix the signal with other speakers. To properly configure the filter, you need to know in advance how this is done.

First, you need to make sure that the initial parameter was not too high, and that the woofers on the subwoofer do not overlap: this risks leading to unnecessary emphasis on one frequency level (about 120 Hz) and unclear sounding of the acoustics. But if connected too low, there may be a large gap between the car signal and the speakers.

At the start, it is recommended to set the LPF filter at a frequency of 80 Hz, and then conduct a sound test and change it as desired until it sounds as the owner requires. It’s better to deactivate the filter on the radio. When there is a chance to apply LPF on the main device, you need to activate it only there. You should not run the filter at the same time as the amplifier.

Setting up a subsonic

Subsonic is an infrasonic format filter that can block ultra-low frequencies that always appear in some compositions. These frequencies cannot be heard at a typical threshold because they operate below the threshold of human hearing. But when they are not initially trimmed, the device will consume additional energy through startup relative to the all-in-one.

You can set up an active subwoofer in your car, automatically blocking infra-low frequencies - the device will be able to effectively reproduce only those that are present within the established limits. Thus, unpredictable failure of a two-coil subwoofer after accelerated movement of the diffuser is eliminated.

The speaker will try to repeat frequencies that lie outside the perceptible range (20-25 Hz and below). Then the diffuser will speed up, which risks causing the two-coil device to exit near the gap and result in damage. Subsequently, the quality of reproduction of the required bass range increases in quality, in addition, the volume increases.

To tune the subsonic, you should set it at least 5 Hz below the level of the bass reflex port. To do this, turn on the switch and move it to the desired data. When the subwoofer is configured correctly, passengers in the car will not hear it, since it should not provoke interference with the central signal.

Setting the input sensitivity GAIN

Sometimes car owners do not know how to correctly adjust the input sensitivity. This value demonstrates how it is possible to apply a signal to the input in order to result in rated power. It should be adjusted for the incoming flow voltage. It is worth adjusting the input sensitivity correctly to prevent accidental signal changes, distorted sound, or other problems with the speakers.

To change the GAIN values, you will need:

• digital voltmeter, which can measure AC voltage values;
• test CD or file where a sine wave is saved with an initial level of 0 decibels (it is important not to use a weak test signal);
• instructions for the subwoofer for the car, which mentions the permissible output voltage.

You must disconnect the speaker wires from the unit and ensure that the bass, equalizers, and other settings on the head unit are turned off to get clear sound. The level of input sensitivity should be minimal, so it is better to switch to bridge mode. You can use an oscilloscope to collect more accurate data.

Step-by-step instructions for serial connection

In this embodiment, the resistance is summed up and calculated using the formula:

R1 - first speaker,

R2 - second speaker.

In this case, R1 must be equal to R2, otherwise the speaker system will quickly wear out and the expected sound effects will not live up to expectations. Using this scheme, you can connect as many speakers as you like, but their R value should not exceed the maximum permissible R of the amplifier. It is also worth considering that the more speakers are connected in series, the less sound power will be output.

1. Negative 1 is connected to the positive channel of column 2.
2. Positive 1 is connected to the negative terminal of the device.
3. Negative 2 is connected to the positive output.

The serial connection of three or more speakers is carried out according to the same scheme, where each subsequent one is polarly connected to the previous one, and their outermost contacts are polarly connected to the terminal of the device.

DIY setup without a subwoofer

In this case, the speaker system consists of four speakers. In this option, the settings will be the simplest. With this design, the amplifier filters are disabled. All parameters are set to zero, and the crossover selector is set to the “Flat” position. With these settings, the speaker, amplifier and all other components will produce high-quality sound without distortion.

All that remains is to expose the head unit. This can be done by selecting from ready-made equalizer settings. The volume is turned up to 90 percent and the track starts. During the sound process, the gain is adjusted until the sound is loud and clear, without distortion. This is how you can set up a simple amplifier for the average music lover.

Parallel connection diagram

When connected in parallel, the load resistance drops and the output power increases in proportion to the number of speakers. Here you should pay attention to the maximum permissible load on the amplifier and the number of channels.

Most models are designed for a load of 2 ohms, less often 1 ohm, but for high-quality sound and longevity of the equipment, it is advisable to create an optimal load for the device. So, for example, when connecting two speakers with R = 4 Ohms and two speakers with R = 8 Ohms to an amplifier with R = 8 Ohms, we get the permissible resistance of all speakers (4+4+8+8=24 - total; 24: 4=6 - total resistance per device).

1. The negative channel of speaker 1 and speaker 2 is connected to the positive terminal of the device.
2. Positive - to the negative contact of the same channel.
3. All others are connected according to the same principle.

Bridge connection of amplifier channels (Bridge ON-OFF)

With a bridge connection, the amplifier combines the positive wire of the speaker output of one amplification channel and the negative wire of the speaker output of the second amplification channel. By combining the left and right channels in this way, we get one much more powerful mono channel for connecting a subwoofer to it. Its power is four times greater than the power of one channel before the bridge connection mode, since power is the square of the voltage divided by the resistance, which remains unchanged. Let's say the output voltage on one channel is 15 Volts, therefore its power will be equal to:

15(15/4Ohm) = 56.25 W.

With a bridge connection, the voltage of the combined channel will become equal to 30 Volts, and the power will become equal to:

However, it should be remembered that an increase in power does not lead to a proportional increase in the volume (dB) of the sound. Doubling the power results in an increase in sound pressure level of only 3 dB. In our case, with a fourfold increase in power, the sound pressure will increase by 6 dB.

In order to properly configure the amplifier, you must perform the following steps:

1. Turn the gain control on the amplifier to minimum (minimum gain).

2. Raise the volume on the head unit to the maximum level at which distortion has not yet begun.

3. On the amplifier, slowly raise the gain control to the level before distortion (maximum “clean” gain).

4. Turn down the volume on the head unit to the desired level.

As a result of these actions, we will obtain the maximum sound pressure level (SPL) that the sound system can produce.

Capacitors are devices that can store and release electrical charge. The capacitance of capacitors is measured in Farads. A capacitor with a capacity of 1 F accumulates an electrical charge equivalent to a current of 1 A lasting 1 second. A charged capacitor discharges very quickly, making it very useful for maintaining power to powerful car audio systems.

The amplifier may briefly consume up to three times its average power consumption during operation. During these short periods of time, the car's battery is not able to supply the amplifier with the required current strength, and as a result, a voltage drop occurs in the car's power system, which leads to sound distortion (dull bass). Installing a capacitor successfully solves this problem. The capacitor, quickly discharging, smoothes out the voltage drop in these short periods of time and provides the amplifier with smooth power.

Capacitors for such purposes are available with capacities from 250,000 mF to 2,000,000 mF. Capacitors are selected according to the rule that for every 100 W of amplifier output power, 100,000 mF of capacitor capacitance is installed.

Parallel-serial connection diagram

This is the most popular connection method, as it allows you to regulate the power supplied to the device and avoid overloading it. This results in high-quality sound. This connection scheme combines both methods.

Step-by-step instructions for connecting four speakers to two channels of the device.

1. The negative terminal of speaker 1 is connected to the positive terminal of speaker 2.
2. Negative contact 3 is connected to positive
3. Positive contact 1 is output to a common positive channel with positive contact 3.
4. Negative contacts 2 and 4 are connected to a common negative contact.
5. The derived common channels are connected to the amplifier, taking into account the polarity of the contacts.

In the same way, subwoofers can be connected to this system if two-channel equipment is used. With four channels, the subwoofers are connected separately by a bridge.

Watch the connection video

Adviсe

Let's give some advice.

1. In addition to calculating the load on the equipment in a specific connection, it is important to correctly select the wires that match the resistance in the circuit. Preference can be given to acoustic wires, which give the purest sound at the output, or to ordinary wires with R not lower than 4 ohms.
2. To avoid damage and short circuit, the polarity of the contacts + to - should be strictly observed.
3. When you turn on the radio for the first time to check, the volume should be minimal. If the sound is distorted, the equipment should be turned off immediately. This effect occurs when the polarity of the connections is not observed, which will have to be corrected.

Connecting a two-channel amplifier to speakers

When connecting the power to the amplifier, it is better to choose wires with as large a cross-section as possible, here the expression “you can’t spoil the porridge with oil” will be true, the main thing is that there are no problems with laying the wire through the car. The fuse rating should be equal to or slightly greater than the total amount of fuses, for example: the radio has 10A, and the amplifier has 30A, therefore, the fuse rating next to the battery should be 40-45A. To turn on the amplifier remotely, a wire of normal cross-section, like that of a radio, is suitable. The wire for turning on the amplifier is usually blue on the radio, in very rare cases it is a different color.

To connect an amplifier, you can buy ready-made sets of wires; pay attention to which amplifier the set is for, for a 2-channel or 4-channel amplifier. If you decide to take a set of wires, immediately buy an additional ground wire (-) 5 meters long, since it is 1 meter long in the kit. Manufacturers of the kits believe that attaching the ground wire to the car body is no worse than connecting the wire to the negative terminal of the battery, so 1 meter of wire is included in the kit. But in reality this is not so and it is still better to take the mass from the battery.

The signal wire (RCA) from the radio to the amplifier looks like a tulip, which is quite familiar to everyone. Connector for the signal wire in the “Input” amplifier.

There may be more options in the radio (Output, Front, Real, SUBWOOFER)

The blue wire in the diagram (remote turn-on wire) is connected to the “REM” terminal on the amplifier.

Red wire +12V, amplifier power supply

Question about connecting a 2-reel sub to a 4-channel

One of the advantages of an active filter is the ability to fine-tune frequency cuts. It is connected to the radio and various speaker systems or a subwoofer can be connected to it as a load, but first things first.

Simple homemade products for a car, tips for car enthusiasts and do-it-yourself diagrams

If your amplifier or active subwoofer does not have such an input, what should you do in this case? Such filters can be built into the acoustics or form a separate unit. Therefore, to power the amplifier or active subwoofer, separate wires are routed from the battery. Connecting a passive Let's consider a sequential algorithm for installing a device.

As in the previous situation, you need to look at the resistance of the amplifier and then think about how to connect it. Next, insert the wire into the ferrule sleeve and crimp it carefully. The program showed a length of exactly 50 cm, but they couldn’t hold it for that long, so they tilted it.

But in this case, appearance does not play any role. Subwoofer connection diagram 2x2 Ohm, 4x4 Ohm, 1x1 Ohm. How to properly connect an amplifier! Connection diagrams!

What you need to connect

First, the ability of the car amplifier to operate in bridge mode is checked. If this device is not designed for it, it will quickly fail due to overheating and overload. It is also worth considering that the operating resistance will change. With a bridged connection, audio will only be output from one channel.

To connect the amplifier you will need:

• speaker cables;
• power wires;
• speakers and subwoofer;
• fasteners.

How to choose a wire cross-section

Since the power consumed by the bridge car amplifier from the on-board network will increase several times, the cross-section of the wires used to connect the power supply must be at least 3 mm. This will help avoid sudden muting and distortion of the sound at high volumes.

The thickness of the speaker cables should also not be thin to ensure effective sound transmission through the bridge system.

Fuse selection

The fuse rating is selected based on operational reliability. If the burnout of an already installed fuse-link occurs frequently, then the rated current does not correspond to the increased energy consumption of the device.

A fuse with a higher value should be installed. You can also include an additional 30 A fuse in the positive wire gap to increase the protection of a two-channel amplifier connected via a bridge circuit from overload and short circuit.

Preparation

At the preliminary preparation stage, the car owner develops a connection diagram for the amplifier, taking into account the location of standard equipment. If additional loudspeakers (for example, a subwoofer or tweeters) are installed in the vehicle structure, it is necessary to consider the method of installing the devices. Based on the data obtained, the car owner purchases power cables, interconnect cords with tulips, additional decorative elements and other parts necessary when installing amplification equipment.

Wires

To connect the amplifier to the vehicle's on-board network, you need a special cable designed for the current consumed by the additional equipment. The cord is selected based on the power of the installed components, taking into account additional heat losses (up to 30%). For example, when switching a 2-channel amplifier with a nominal power of 200 W, the thermal load must be taken into account, which is approximately 60 W. The resulting power value requires the use of a cable rated at 21.6 A (it is recommended to make a safety margin of another 10-15%).

To calculate the wire cross-section, there are special tables that display the dependence of the cable diameter on the transmitted current. For installation, use a cord with a copper core that does not collapse under vibration loads

When purchasing a cable, you should pay attention to the thickness and characteristics of the insulation, since low-quality materials spontaneously crack when the temperature drops to -15°C

Fuse

It is necessary to install a fuse in the power supply circuit of the amplifier in the car to prevent the product from igniting in the event of a short circuit (for example, due to destruction of the insulation of the power cables). The design of the equipment includes standard protection elements; an additional insert is located near the battery terminal. To properly connect a car amplifier, you must use fuses with a rating of no more than 50 A.

Interconnect cable

The mounted amplifier must be connected to the head unit using a special interconnect cable equipped with metal mesh protection. The screen reduces the likelihood of interference occurring during the operation of the ignition system and electronic components of the vehicle. It is not recommended to lay patch cords near standard control units and electric motors installed in the vehicle's air conditioning system.

Wiring

The wires are laid in such a way as to avoid damage and kinks. To do this, the wiring is placed in a flexible plastic tube of suitable diameter and laid under the floor covering.

To protect and shield speaker cables, they can be routed inside a split metal tube that can be grounded.

Amplifier power

It is taken directly from the car battery terminals. Other power connection options are undesirable, as they will lead to unstable operation of the bridge amplifier and other devices powered from the same circuit.

If the generator and battery cannot handle the high power demand, then power shortages will occur. The lights will blink when listening to music at high volume. A larger battery and a more powerful generator should be installed to ensure proper power levels.

Grounding

This point is of great importance for the reliable operation of an amplifier connected in bridge mode. The ground connection can be made directly at the installation site of the device. To do this, take a short piece of thick insulated wire. A common bare braided cable will do.

One end of the wire is connected to the negative terminal of the car amplifier, and the other is inserted between the bracket or bar securing the device and the floor of the body.

After this, the connection point is treated with WD-40 to increase reliability and protect against corrosion, and the nut or bolt is tightened.

To avoid interference in the speakers, the body of the device should not be allowed to come into contact with the body of the car. Otherwise, ground loops will form, which will lead to unpleasant interference. To isolate the housing from the car body, you can place a strip of rubber under the mounting bracket.

Where and how to install

Before you begin, you should select a suitable installation location. Some car models have niches for placing speakers. This fact makes the task easier. If the location for the speakers is not prepared by the manufacturer, then you need to choose it yourself.

It is recommended to install the front pair of speakers in the car on the outermost sections of the dashboard. Another suitable option is the front door housing. In this case, not only high sound quality is achieved, but also the most reliable fixation of the device. To install speakers in doors, measure the diameter of the speaker and cut a hole for it in the door trim.

The rear pair of speakers is most often placed on the floor in the luggage compartment. However, it will require some work to achieve good sound. The standard trunk shelf is removed, and an acoustic podium with speakers is installed in its place.

How to connect

Connecting a two-channel amplifier using a bridge circuit is carried out in different ways depending on the radio, speakers and subwoofer used.

The connection method is also influenced by the number and characteristics of the components.

Radio tape recorder

The choice of the required method is determined by the connection diagram printed on the device label. Connecting the radio to a two-channel amplifier in bridging mode is carried out in the same way as to a standard one. There are 2 ways to transmit sound from the head unit.

In the first case, the connection is made using linear outputs. In the second case, the radio terminals intended for speakers are directly connected to the amplifier. If 2 amplifiers are used, then the linear output of the left channel is connected to the first, and the output of the right channel is connected to the second. The blue wire with a white stripe from the radio is connected to the input of the amplifier(s) power control relay.

Subwoofer

Before connecting a subwoofer to a two-channel amplifier, you should check its resistance. If the operating resistance of the amplifier is 4 ohms, then the subwoofer connected in bridging mode must have a resistance of 2 ohms. If these recommendations are not followed, the car audio system may become unstable.

To connect an amplifier to a subwoofer, connect its positive lead to the positive terminal of the left channel. The negative wire of the subwoofer is connected to the negative output of the right channel. As a result of this operation, the power of the sound reproduced by the subwoofer becomes higher. If you have a low-pass filter control, set the value from 100 to 250 Hz.

Before connecting 2 subwoofers connected in series, phasing is carried out.

It is necessary to ensure that the speaker cones move in one direction. This provides the necessary sound quality at low frequencies. To carry out phasing, the subwoofers are connected in series.

After this, a AA battery is momentarily connected to the free wires. If the cones move in different directions, then the leads of one of the low-frequency loudspeakers change places. If it is necessary to connect both full-range speakers and a subwoofer, then a crossover is used for this.

Columns

Each bridged two-channel amplifier can only connect one speaker. It is worth considering that the sound of a car audio system in bridged mode will be monophonic due to channel combining. To get stereo sound in a car using the bridge method, there are several ways to connect 2 or more speakers to an amplifier.

One of them is to use another amplifier. Another is to connect the desired number of speakers in series to the bridged output. Full-range speakers are connected in the same way as a subwoofer. The high and low pass filter settings do not change. Thus, connecting a 2-channel amplifier via a bridge circuit will not cause any particular difficulties if the work is carried out correctly.

Setup Instructions

The amplifier is configured in accordance with the recommendations set out in the operating instructions. To adjust the parameters, buttons and rotary switches are used, covered with a protective panel. Rotating correctors are recessed into the body, which reduces the likelihood of accidental position changes. To rotate the element, it is recommended to use a flat blade screwdriver.

A control diode of the power supply is installed on the equipment case; further adjustment of the device is allowed only when the green lamp is turned on. When using standard factory settings of the equipment, the sound picture is blurry. Adjusting the parameters allows you to highlight low and high frequencies, as well as reduce sound distortion.

Amplifier setup for four speakers without subwoofer

After completing the connection of the four-channel amplifier and checking the operation of the electrical circuits, you need to configure the acoustics according to the following method:

1. Turn the knob labeled Gain or Level to its minimum position.
2. When using standard door speakers, you need to turn the HP filter control to the maximum position (indicated on the body as Full). If the car has small-sized acoustics with a diameter of up to 100 mm (in the instrument panel or front pillars), then it is necessary to set the corrector to the position corresponding to 120 Hz.
3. Turn off the bass boost function and turn off the graphic equalizer.
4. If you connected a 4-channel amplifier with channel separation, then you need to activate the HP and LP filters (for high-frequency speakers and mid-range speakers, respectively). The controls are set to the position corresponding to 4 kHz.
5. The design of the amplifier unit has a HiLow Level switch, the position of which depends on the type of connection of the equipment to the head unit. When a signal is fed through speaker cords, the Hi position is set. If you connect the equipment to the linear outputs of the radio, the switch is moved to the Low position.
6. Turn on the head unit, which contains a laser disc with musical compositions; you can install a removable drive with recordings in MP3 format (with a high bitrate). Check the position of the loudness selector (should be off), and then smoothly turn the volume control until wheezing appears in the sound picture. Carefully turn the corrector back, determining the boundary of the appearance of interference.
7. Then the user adjusts the position of the Gain or Level control, the adjustment is made in the same way as adjusting the sound volume.
8. Determine the broadcast volume for the rear channels, comparing the settings with the parameters of the front speakers. If the car owner has difficulty adjusting the acoustic equipment, it is recommended to contact a specialized service center.

Setting up an amplifier for a subwoofer and speakers

The adjustment is made by analogy with the adjustment of a system with standard acoustics. To ensure an improved sound picture, it is recommended to relieve the speakers from broadcasting low frequencies. This action allows the diffuser stroke to be reduced and improves the reproduction of mid frequencies. The HPF corrector is used for adjustment; the position of the potentiometer is determined by the user by ear. Some car owners do not turn on the HPF adjustment due to distortion of the sound picture.

The use of bass boost for a subwoofer is not recommended since it affects the band above 40 Hz. When using a subwoofer with a bass reflex, the subsonic filter is turned on, which is adjusted to a frequency 2-5 Hz below the bass reflex value (indicated on the equipment).

A bridge connection of a 4-channel amplifier will allow you to get high sound power with a subwoofer at no extra cost. Using this method, you can make an audio system of 4 or even 8 speakers and a subwoofer, so you can enjoy high-quality sound when listening to music or watching movies.