Make a car amplifier. A homemade subwoofer amplifier is an economical way to get a useful device

Make your own amplifier from a car radio

For some reasons, many car enthusiasts are in no hurry to get rid of old car radios that have served their purpose. They are not at all embarrassed by the outdated design of this antediluvian device, nor by the fact that its cassette receiver has not been used for its intended purpose for a long time and the equalizer settings are so primitive that the purity of the sound is regulated only by the volume knob of the car radio itself.
In this case, there are only three reasons for the car owner’s enduring love for his “gramophone”:

• Sentimentality;
• Deafness;
• The price of a new and good car radio is a significant part of the cost of the car itself.

Since purely medical workers are competent in the first two reasons, I propose to consider the third option, which contains real instructions on how to make a sound amplifier with your own hands from a car radio that you were about to throw away.

Car radio resuscitation - Method one

So, in order to make an amplifier out of a car radio, we need to ask ourselves the last two control questions:

• Am I satisfied (if I have a conscience and want to ask my passengers) with the output power and “cavity” of the radio?
• Is the sensitivity of the FM tuner sufficient?

If in both cases you put “pluses”, then you can be congratulated, you have just appreciated the internal contents of this music box, namely:

• Digital tuner;
• Sound control unit;
• Stereo - Quad amplifier.

Well, now let's get to the fun part - how to make an amplifier from a car radio?
In solving this dilemma, thanks to modern technologies and the technical characteristics of the old, but necessary, head unit, we will significantly facilitate our task by connecting a digital sound source to the old radio. Well, here we have several options to choose from.

If your radio is really old, then this means that it does not have such necessary this moment outputs such as AUX-IN and USB port. For this we can use the Car Cassette Tape Adapter Transmitter for MP3.

As you can see in the photo, this adapter is made technically and visually as an analogue of a regular cassette - 100.5 * 63.8-12.0 millimeters. I agree, when you saw this device for the first time, at least you had a slight feeling of surprise and a smile, but wait to judge, you will now understand all the charm and genius of this device.
The principle of turning on this adapter is that you insert it like a regular cassette into the “deck” of a car radio, its head is in contact with the head of the player and by connecting a sound source (player, TV - smartphone, laptop, etc.) via a mini-jack, we We get pretty good sound from the speakers, at least better than some FM transmitters.
In general, everyone is happy - we saved a decent amount on purchasing a car radio (see), the tape recorder thinks it is playing a real cassette)))

Advantages

This:

• The idea itself;
• Price;
• Not bad sound;
• It does not pretend to be a cigarette lighter socket, which, you see, is very important!

Flaws

• Unreliable layout (if you do not use a hammer and screwdriver and do not pull the cable, it will last long enough);
• Another protruding cable!!!
• When playing, you can hear the sound of a running tape mechanism (this can be eliminated either by turning up the volume or turning off the mechanism itself).

Method two

If the cassette tray in your car radio is faulty or missing (do such things really exist?), the FM transmitter mentioned above may well become an alternative sound source.

For its full operation, you will need to insert a flash drive with music files through the USB port or connect another sound source via AUX-IN, then make room for it in the cigarette lighter and tune your car radio to the same frequency as the FM transmitter.

Advantages

• Easy to connect and use;
• Extensive possibilities for connecting various sources with music files.

Flaws

• Constantly occupied standard port for powering the cigarette lighter;
• If the performance is poor, there is extraneous noise and periodic “glitches”.

Method three

IN this method I would also like to talk about one option, how to make an amplifier from a car radio for more modern devices, such as smartphones, tablets, laptops and the like that have Bluetooth adapters.

In this case, the WirelessBluetoothMusicReceiver adapter will help us out, as long as your head unit has an AUX-IN port. Otherwise, you can always use other adapters, adapters and FM modulators capable of simulating additional stereo audio inputs of an audio power amplifier.
Well, if you consider yourself to be one of the normal guys who are not afraid of difficulties and always take a detour, then I can offer you an option not for the lazy in the following method.

Method four

If you are reading this option about how to make an amplifier from a car radio, then by default I assume that you are at least capable of:

• Hold on to the soldering iron;
• Look at the circuit diagram;
• See familiar letters in the documentation accompanying the car radio.

Attention!
At a minimum, you need to realize that all actions occur at your own peril and risk, and also that you should have an idea of ​​at least the basics of electronics theory. Any “tuning” of the insides of a car radio must be done by you in a sober mind and in good memory)))

• We remove the “old lady” from its standard location and disconnect all connectors and wires:

Advice! All subsequent actions are not for “fussing around on your knees”; you need to settle down in normal conditions.

• By dismantling the top cover, we can observe the cassette unit. We are making the very first modernization - we remove interference and noise of electromagnetic origin created by the electric motor of the tape drive, for which we unsolder the positive wire and insulate it.
  It’s not worth tearing it out, what if someone wants to return everything back?

We determine the place where we will solder the AUX-IN output:

• Firstly. We inspect the wires coming from the pickup head; as a rule, they are soldered to the pre-amplifier circuit; you should not solder here;
• Secondly. We find out where the amplified signal comes from pre-amplification, and it goes to the camparator (the microcircuit responsible for switching between the cassette unit and the FM tuner);
• Third. Either by turning on the logic or using the Datasheet (technical documentation) of the preamplifier chip, we find the output of the audio tracks from it. In the case in the photo, these turned out to be heels numbered FPM 1558 and FPM.

Having traced these tracks that connect the output of the pre-amplifier with the comparator signal, we find out where the left and right audio channels are located - by touching the heels of one of the channels with a screwdriver, while an empty audio cassette is turned on, a characteristic crackling sound will be heard in the speakers. Solder the audio cable outputs from AUX-IN to the left (InLeft) and right (InRight) channels. The third pin (InGND) is soldered to the ground (body) of the car radio.

Unfortunately, this instruction cannot contain all the options for soldering the AUX-IN output to the circuits of all kinds of car radios, but I hope you still understand the principle. Moreover, the Internet is full of various videos on this topic.
I propose to stop here, since this topic can go on and on. As they say, there is no limit to perfection, there is only the limit of the imagination of an individual.

Hello! I would like to present to your attention a diagram, photographs and printed circuit boards of a car amplifier. These schemes are easy to find on the Internet. So, let's start in order. The idea has long been to assemble an amplifier for a car; the requirements for the amplifier were as follows:

1. Good sound quality throughout the entire power range.

2. Low harmonic distortion.

3. Well, the power is not inferior to the average price range for factory car amplifiers.

The first thing I started assembling was a voltage converter from 12 to + - 40 volts. I decided to make the printed circuit board from a single sheet of PCB. I used LUT technology. I made the printed circuit board according to my dimensions. PWM assembled on a separate board. In this circuit I added only an additional winding to power the 24 volt AC protection. 8 turns with 0.8 mm wire.

Voltage converter from 12 to + - 40 volts - diagram

Next is the diode bridge for rectification, it was made using 4 diodes HER-307, then a filter from a 1000 uF 50 volt capacitor. I cut out only part of it from this diagram. That is, a stabilizer of +-15 volts. The rest remains as in the diagram.

About winding a transformer

For the transformer I used ferrite rings, Russian, 40x25x11 2000NN glued together. The sharp edges of the ferrite were rounded off with a diamond file. Then I wrapped it with masking tape. The primary winding of the transformer was wound with 0.8 wire. 10 cores folded together, 5 turns evenly distributed throughout the ring. Next it is divided in half. The secondary winds similarly to the primary. The same wire 0.8 and 8 cores folded together. The number of turns is 15 and then divided in half. The output voltage turned out to be +-40 volts, under load the voltage dropped to 2 volts in both arms.

Now I started assembling the audio power amplifier. The choice fell on Likes booster version 6 . I didn't change anything in the diagram. But I ran into some difficulties. In this amplifier, you need to carefully select elements to ensure the symmetry of both shoulders. That is, transistors, capacitors, resistors. Quiescent current 150 mA.

Laikov scheme 6

After soldering all the elements, do this:

1. Set R6 and R24 to the middle position.

2. Short the amplifier input to ground.

3. Unsolder the output transistors.

4. Turn on the power to the circuit.

5. Set R 6 at the amplifier output voltage to 0 V.

6. Measure the supply voltage and +/- 15 V.

8. Turn off the power, connect the output transistors, connecting a 1 A ammeter into the open circuit of the VT10 collector.

9. Turn on the power and R24 set the quiescent current of the VT10 collector within 100 - 150 mA.

10. Measure the quiescent current of VT11; it should not differ from the current of VT10 by more than 5%.

11. The quiescent current of the output transistors can be set in the range from 40 to 200 mA, depending on the desired sound quality, operating mode, thermal conditions, and radiator sizes. The quiescent current must be set at a temperature of the output transistors of 35-40 degrees.

12. Check the operation of thermal compensation by measuring the quiescent currents at maximum temperature heatsinks for output transistors.
The setup is complete. The layout of the Laikov amplifier version 6 is shown below.

I assembled the AC protection according to this scheme

There is no need for configuration if everything is assembled correctly. Printed circuit boards will be in the archive. When testing the amplifier, I removed 98 watts from one channel, then it went into clipping. As the author stated - pure 100 watts. I used radiators from the computer, from the socket AM 3+. Without coolers it gets damn hot because the radiators are too small. I decided to leave the cooler running - now everything is warm. The cooler was powered using a PWM regulator circuit on a timer NE555.

Next, I started assembling the second converter for the subwoofer channel. The scheme remains the same. There are minor changes to the winding of the transformer. I used the same rings, two glued together. The primary remains the same. But the secondary is different, the number of cores is the same, but there are no longer 15, but 21 turns. The output of the converter turned out to be +-70 volts. For the low-pass filter, I wound a separate winding with 0.8 8 turns wire. The stabilization circuit remains as in the circuit. There is also another winding to power the AC protection, everything is the same as in the first converter for Laikov.

I decided to assemble the amplifier itself according to the Holton circuit

Holton circuit diagram

The assembly begins with the installation of resistors, then powerful resistors, diodes, capacitors and small-signal transistors are installed. Care should be taken when installing polar elements. An incorrect connection may result in the device not working or one or more elements failing when the circuit is turned on.

Having completed the installation of all elements, carefully inspect the module to see if all components are soldered in and if they are installed correctly. Only when you are sure that everything is done correctly and all the parts are in place, you can connect the power.

Using crocodiles, attach the probes of the device to the terminals of one of the powerful 0.22 Ohm resistors. Slowly rotating the slider of resistor P1, set the 0.22 Ohm resistor to 18 mV, this will set the current to 100 mA per transistor. Now check the voltage on all other resistors, select the one with the highest voltage. Set the voltage on it to 18mV using resistor P1. Now connect the signal generator to the input and the oscilloscope to the output. Make sure the waveform is free of distortion. If you do not have these devices, connect the load and hear good quality. The sound should be clear and dynamic. AC protection is similar to the first. 24 volt power supply from a separate transformer winding.

The low-pass filter is assembled according to this scheme:

Low-pass filter circuit in a car amplifier

I used 20 by 20 mm aluminum corners and 10 mm plywood. The body is sanded and covered with black leatherette. The coolers are mounted on the rear wall of the case.

The low-pass filter will be fixed on the front panel, and the power terminals for powering this unit will also be located there. And input and output terminals.

The top cover will be made of tinted 4 mm glass. The amplifier has been tested for listening to music. On speakers with 90 and a JBL GT5 subwoofer 1200 watts.

The bass is deep and assertive. Laikov did not reveal its full potential, since the C90 is not suitable for this unit. Overall I am very pleased with the sound of this amplifier. I especially like the very strong and pleasant bottom. I was with you Ivan Aleksandrov.

Discuss the article CAR AMPLIFIER

This power amplifier is based on the PA100, described in detail in the application from National Semiconductor's AN1192

When I assembled my powerful homemade 4-ohm speakers, the amplifier could not “drive” such a load, so it was decided to assemble more powerful amplifier. I have designed a power amplifier circuit that uses two LM3886s per channel in a parallel circuit. At an 8-ohm load, the output power of the amplifier is about 50 Watts, at a 4-ohm load it is 100 Watts. This amplifier uses four LM3886 ULF chips.

By the way, Jeff Rowland uses LM3886 in some of his Hi-Fi designs and has good feedback. So an inexpensive amplifier can also be of high quality!

The LM3886 chip is connected as a non-inverting amplifier. The input impedance of the ULF depends on resistor R1 (47 kOhm). Resistor R20 (680 Ohms) and capacitor C20 (470 pF) form a high-pass filter on the RCA input connectors. Capacitors C4 and C8 (220 pF) are used to filter RF at the inputs of the LM3886 chip.

When assembling the amplifier, in some places I used high-quality capacitors: C1 (1 µF) "Auricap" for DC filtering, C2 and C6 (100 µF) "Blackgate" and C12, C16 (1000 µF) "Blackgate".

The circuit diagram of the amplifier is shown below.

The development of the printed circuit board was carried out taking into account that the power ground (supply) and signal ground were separated. The signal ground is in the middle and is surrounded by the force ground. Near C5 they are connected by a thin path. The design of the printed circuit board was carried out in the PADS PowerPCB 5.0 program.

I didn’t make the printed circuit board myself, but gave it to a company. When I picked it up, I discovered that some of the holes were smaller in diameter than needed. I drilled it out myself by hand. The photo below is a photo of the board.

Resistors 1kOhm and 20kOhm were manually selected with an accuracy of 0.1%. As output resistors, I used six resistors with a nominal value of 1 Ohm 0.5 Watt 1%, because a 3 Watt 1% resistor is difficult to find.

I used an isolated version of the chip - LM3886 TF, so I directly connected it to the case and heatsink through thermal paste.

Isolation capacitor "Auricap" 1uF 450V. A high quality capacitor was purchased because it is involved in the main signal circuit.

Capacitors in the high-pass filter: "Silver Mica" 47pF and 220pF.

The power filter used a "Blackgate" 1000uF 50V capacitor

Condensers C2 and C6 are also from Blackgate with a nominal value of 100 µF 50 V. For best results, it is better to use bipolar capacitors, but I used electrolytes because... bipolar ones would not fit on the board.

The filter chain R20 (680 Ohm) + C20 (470 pF) is placed directly on the RCA connector. This helps filter out RF noise before it reaches the amplifier board.

A 0.1uF power supply decoupling capacitor is soldered to reverse side amplifier boards directly onto the LM3886 leg, this allows for better filtering of RF noise.

The LM3886 chip is mounted on an aluminum radiator, and then to the amplifier body. Outside the case I attached 3 more radiators from PC processor fans. Thermal paste was used throughout for better heat transfer.

With all these heatsinks, the amplifier heats up quite a bit at medium volume.

In the power supply I used an LT1083 adjustable voltage regulator IC. In front of it I placed capacitors with a capacity of 10,000 μF and after - 100 μF. The advantage of using an adjustable voltage stabilizer is that there is virtually no ripple voltage. Without it, a small 50/100 Hz noise is heard.

Powerful MUR860 diodes were used in the diode bridges.

The LT1083 voltage stabilizer can provide current up to 8A.

The transformer was used with a power of 500VA 2x25V. After the stabilizer, the voltage is 30 Volts.

In the future I plan to replace the stabilizer with a more powerful one (see diagram below). The TIP2955 transistor is capable of withstanding currents up to 15A.

After assembling the amplifier, I measured the DC voltage and found an offset of about 7 mV at the speaker terminals. The voltage difference between the two outputs of the microcircuits is less than 1 mV.

The sound of the amplifier is somewhat similar to the sound of the amplifier I previously assembled on the LM3875 - very clean. There is no noise, no hissing, no buzzing. Compared to the LM3875 amp, this amp delivers about twice the power through my 4 ohm speakers and delivers deep, punchy bass and good dynamics.

List of radioelements

Designation	Type	Denomination	Quantity	Note	Shop	My notepad
	ULF
U1, U2	Audio amplifier	LM3886	2			To notepad
C1	Capacitor	1 µF	1			To notepad
C2, C6		100 µF	2			To notepad
C3, C7	Capacitor	4.7 pF	2			To notepad
C4, C8	Capacitor	220 pF	2			To notepad
C5, C9	Electrolytic capacitor	10 µF	2			To notepad
C10, C11, C13	Capacitor	0.1 µF	3			To notepad
C12, C14	Electrolytic capacitor	1000 µF	2			To notepad
C20	Capacitor	470 pF	1			To notepad
R1	Resistor	47 kOhm	1			To notepad
R2, R3, R7, R8	Resistor	1 kOhm	4			To notepad
R4, R9	Resistor	22 kOhm	2			To notepad
R5, R10	Resistor	10 kOhm	1			To notepad
R6, R11, R13-R16	Resistor	0.5Ohm 1W 1%	6			To notepad
R12	Resistor	2 ohm	1			To notepad
R20	Resistor	680 Ohm	1			To notepad
	power unit
U1, U2	Linear regulator	LT1083	2			To notepad
D1-D8	Rectifier diode	MUR860	8			To notepad
C1, C4	Electrolytic capacitor	10000 µF	2			To notepad
C2, C5	Capacitor	1 µF	2			To notepad
C3, C6	Electrolytic capacitor	100 µF	2			To notepad
R1, R2	Resistor	100 Ohm	2			To notepad
R3, R4	Trimmer resistor	2.5 kOhm	2			To notepad
TX1, TX2	Transformer	220/25V	2			To notepad
	Powerful stabilizer
N1, N2	Linear regulator	LM317	2			To notepad
V1, V2	Bipolar transistor	TIP2955	2			To notepad
V3-V12	Rectifier diode	MUR1560	10			To notepad
V13, V14	Rectifier diode	1N4007	2

Every car owner knows that good audio systems are quite expensive. The price of just one of the main elements that allows you to produce high-quality sound - an amplifier - can be more than a hundred dollars. Therefore, many connoisseurs of high-quality sound are thinking about how to make a music amplifier for a subwoofer with their own hands. We will talk about this below.

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Tools and materials

If you decide to equip your car with a high-quality 12-volt radio, you will need a subwoofer and an amplifier to ensure good sound.

The output transistors must be provided with cooling; to do this, the elements can be bent towards the board, with their contacts facing up. After this, thermal paste must be applied to the contact surfaces and a dielectric film must be placed, and only then radiators are mounted on top. Thanks to this, you can slightly reduce the dimensions of the latter and generally save space in the case.

Since installing a subwoofer involves using an amplifier for a car, it will be necessary to isolate the low frequency range from the incoming pulse. The circuit itself is single-channel, so it is necessary to install a channel adder at the input to the pulse processing device. This will convert a two-channel pulse into a single-channel one.

As for the rectification and switching device, this device consists of several components:

1. A switching device necessary to notify the driver that the amplifier is ready or not ready for operation. Notification is carried out thanks to two diodes - red and green.
2. Rectifier device. This device is necessary to stabilize the pulses that are transmitted to the main control unit.

Before you make an amplifier for a 12-volt subwoofer, you need to prepare one of the main components of the device - the housing. Of course, this element is needed, otherwise where to install the circuit? Alternatively, you can build the case yourself from plywood or purchase a ready-made one, it all depends on your capabilities and preferences. For example, the amplifier can be connected to the housing of a DVD player. Such a device is small in size, usually has a stylish design, and its connectors, if necessary, can be converted to connect to car subwoofers.

A more optimal option would be to use aluminum and, most importantly, a whole case, which can also serve as a radiator. As you know, circuits heat up during operation, as a result of which, when using a wooden case during manufacturing, you will have to think through a cooling system. Moreover, this system must be of the highest quality. Moreover, in some cases it is even necessary to do active cooling. Therefore, using an aluminum case is the most optimal option (video author - AKA KASYAN).

Manufacturing instructions

The amplifier can be assembled after preparing all the main elements. A 12-volt device can be assembled without any problems by connecting all the components and placing them in the case. Thanks to the voltage of the conversion device (transformer), a small fan can be installed on the device body. Thanks to it, air flow will circulate in the system, which will cool the circuits and protect them from overheating, and therefore premature failure.

When connecting with a block, it is necessary to use wires in cambrics. If the wires come into contact with each other, this can lead not only to the formation of a short circuit, but also to burnout of the constituent elements in principle. The units must be installed in the housing in such a way that air can circulate freely between these components. The circuit must be fixed as firmly as possible, otherwise the 12-volt amplifier made will rattle while driving and when the subwoofer is operating.

Conclusion

During work, be careful - if you make mistakes, the blocks may fail. Only take on this venture if you have basic electronics skills. If you have never performed such tasks before, then it is better to entrust this task to specialists.

Sorry, there are no surveys available at this time.

Video “Making an amplifier at home”

The process of making an amplifier at home is presented in the video below (the author of the video is Ivan Aponasenko).

To ensure high-quality sound of music in a car, a consumer can purchase an expensive car radio and subwoofer. But, in addition, the installation of an amplification device is necessary. In order not to spend money on buying it, you can build an amplifier for the car with your own hands.

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Why do you need a car audio amplifier?

When the sound is activated at full power, car radios begin to produce noises and wheezing that are unpleasant for human hearing. This is due to the fact that the standard amplifier for a car audio system is too weak and cannot cope with the load that is placed on it. Especially if the audio system is supplemented with a subwoofer. Amplifiers can be used to eliminate extraneous and unpleasant noise.

The amplification device should not change the sound; its purpose is to maintain sound quality at the appropriate level.

The Treicer100 channel clearly answered the question of the purpose for which amplification devices are installed in cars.

Main characteristics of audio amplifiers for cars

When choosing a device to amplify the volume, you need to pay attention not only to the manufacturer, but also to the main characteristics.

These include:

• device class;
• number of channels;
• rated output power value;
• maximum and minimum reproduced frequency parameter;
• device sensitivity;
• the amount of harmonic distortion, as well as the noise-to-signal ratio.

Device class

On sale you can find devices of the following classes:

The last two options are more popular, so you should focus on them:

1. Class AB devices are characterized by high quality output pulses, but a reduced efficiency. As a result, the output power will be low, out of 100 W at the output no more than 50 W. The dimensions of such devices are larger, since about half of the power is released in the form of heat flow, which must be dissipated using radiator devices.
2. Type D devices do not use powerful transistor mechanisms. But the output power will be higher, and the size of the amplification device will be smaller. The efficiency parameter in D-amplifiers will be up to 95%, but the cost of such equipment is much higher. Using a Class D amplification device will allow the consumer to connect a powerful subwoofer to the car radio.

The Ensemb channel showed practical examples and spoke in detail about the classifications of car amplification devices.

Number of channels

Amplifier devices can have a different number of channels:

1. Monoblocks or single-channel equipment are used to connect a subwoofer to a car radio installed in the car. Monoblocks may not have a high-pass filter device, but it is important that they be equipped with low-pass filters. The range of playable frequencies in such devices, as a rule, shifts downward, and the maximum power parameter is usually no more than 250 Hz. If you plan to connect a powerful subwoofer, the amplification device should be equipped with an ultra-low frequency filter element, this will cut off harmful and unpleasant sounds. If the standard audio system does not have a bass level control, then the monoblock must be equipped with this function.
2. Dual-channel equipment is a more versatile type of device. Such amplifiers are used to connect two speakers or one powerful subwoofer using a bridge circuit. The amplification procedure in two-channel equipment is performed in the range audible to the human ear - from 20 to 20 thousand Hz. Such amplifiers are equipped with low- as well as high-frequency filtering devices.
3. Three-channel devices are used to connect two speakers and a subwoofer. Depending on the manufacturer, such equipment is usually equipped with additional functions for working with subwoofers. As a rule, these are filter elements and bass regulators.
4. A universal option - equipment designed for 4 channels is usually used to create a complete audio system. This device is made of two amplifiers with 2 channels each, which are installed in one housing. Each device is equipped with its own crossover, which makes it possible to use the equipment to connect with 4 speakers or two speakers and one subwoofer. Sometimes two channels are used to play high frequencies, and the other two are used to play low frequencies.
5. Devices designed for five channels. Such equipment is used to connect to a subwoofer and four speakers.

Output power value

This parameter is one of the main ones that must be taken into account when purchasing. The output power value represents the value at which the equipment can operate for a long period of at least 60 minutes. To mislead consumers, device manufacturers may include peak power numbers on packaging. This value represents the power that the equipment produces for a short time. But long-term operation at this setting can lead to equipment damage.

The output power parameter is a value inversely proportional to the value of the internal resistance of the installed speakers. If their resistance doubles, then the power decreases by 50%. When connecting two speakers to the same amplifier channel, the impedance value will change. If it is necessary to use a pair of channels, you must make sure that the equipment allows such a connection.

Playback frequency

The playback frequency parameter covers the entire playable range of 20-20000 Hz. It is possible that these values ​​may be exceeded, but in fact this does not matter. In single-channel equipment used to work with subwoofers, the highest frequency can be up to 300 Hz. This is enough for high-quality work of the subwoofer; there is no point in losing a higher frequency.

Sergey Lebedev spoke in detail about adjusting the frequency parameter when operating a car amplifier.

Distortion parameter and noise-to-signal ratio

If a consumer values ​​high sound quality, it is important to pay attention to these characteristics. The amount of distortion represents the noise that is introduced into the reproduced pulses. Increased distortion may result in a loss of sound clarity. In this case, the sound itself will be duller, hissing will appear, in particular, with increasing volume.

The harmonic distortion parameter is the ratio of the value of the introduced harmonic to the amplitude of the useful pulses. Providing high-quality sound is possible with 1% harmonic distortion at any frequency. Human hearing will not be able to distinguish harmonic distortion of less than 0.5%, so there is no point in buying expensive amplifiers with a lower parameter.

In addition to harmonic noise, amplification equipment also reproduces random noise; the source can be:

The magnitude of this noise is characterized by the ratio of sound to impulse. This value determines what the noise will be if the pulse at the equipment input is zero. For high-quality sound, this value should be at least 75 decibels. If the car has an elite premium radio, then this parameter must be at least 95 decibels.

Sensitivity

The parameter represents the value of the input pulse at which the equipment allows rated power signals to be reproduced. Machine amplification devices are equipped with control devices, which allows them to be installed on any multimedia systems. If the consumer plans to connect an amplification device to the output of the preamplifier of a radio or other equipment or crossover, one point must be taken into account. The selected device must have the function of adjusting the sensitivity parameter. And the output pulse of the device installed in the chain before the amplifier must be within the sensitivity range of the equipment.

To choose a quality device, you need to make sure that there are protections added to the equipment by the manufacturer. It is desirable that the amplification device be protected from overload and short circuit in the electrical circuit. When purchasing, you need to take into account the size of the equipment. The powerful device is characterized by large dimensions, so before installation you need to think about where to place it. The installation location must be protected from moisture and dust, but have free access of air to cool the radiator.

The Vinokurov Audio channel spoke in detail about setting sensitivity parameters in car audio systems.

The process of making amplifiers with your own hands

It is allowed to connect not only a branded amplifier to the car, but also a device made independently. The assembly procedure is recommended for consumers with knowledge of electronics.

How to make a high-quality amplifier case?

You need to assemble a homemade amplifier after the housing is ready. It must fit all components and equipment assemblies. You can purchase a finished product, but you can build it yourself from plywood. To connect the equipment, it is possible to use a housing from a car radio. The device has the required dimensions and design, and for connection it is possible to convert the connectors for a subwoofer.

The best option is to use a ready-made housing made of aluminum; this material will cool the equipment. When the device operates, all components of the circuit heat up, therefore, if the product is made of wood, the consumer needs to think about high-quality cooling. Active cooling systems are allowed, so installing the amplifier in an aluminum case is the best option.

Radioblogful channel. The soldering video blog described in detail the creation of a housing for an amplification device made of aluminum.

Sound amplifier for subwoofer

Making a subwoofer for a car radio consists of four stages:

1. Selection or independent development electrical diagram devices.
2. Performing a task to process an audio signal.
3. Assembly of the stabilization block of the power electrical circuit.
4. Assembly of all components into a single device.

Features of the amplifier assembly:

1. A board is selected that must have built-in overheating protection; all branded devices are equipped with such an element. The microcircuit must be protected from short circuiting. It is possible to add an error detection system to the board; for this, a diode light source is installed. It will blink in case of overheating or short circuit.
2. Then the consumer draws a printed circuit board; for this, the use of LUT technology is recommended. If you don't have such a printer, you can use a marker with a stroke.
3. Holes are drilled on the board to install the component elements, after which they are mounted. Before installation, the board is tinned and the elements are fixed on it. It is recommended to cover the tracks that will be used to power the device with solder or solder a piece of wire on them. The solder should be thick.
4. An electrical capacitor device with a large capacity and the required voltage level is installed in the power supply circuit. The example uses a 16V 4700 µF capacitor.
5. The microcircuit is installed on the radiator device. It is recommended to use larger radiators than indicated in the photo, or you need to make an active cooling system. This will require the use of a cooler; fans from personal computers can be used.
6. When the assembly of the amplification device is completed, it is necessary to build a filter element for power supply. It will be needed to connect the equipment to the machine's electrical network.
7. The inductor is wound with a cable with a cross-section of no more than 1.5 mm2, the procedure is performed on a ferrite ring. The diameter of the latter should be 20 mm, and the number of turns will be 5. It is allowed to use a ring from a PC power supply or a 12-volt transformer device. The size of the element may vary; if it is missing, purchasing a new device is allowed.

Audio signal processing

An adder is used to process audio signals. The device is designed to sum and also increase the power parameter of the audio channel. If one subwoofer is installed in the car, then the unit is equipped with three regulatory elements. One of them regulates the cutoff of audio frequencies, the other controls the volume, and the third is a phase rotator. This allows the speakers and subwoofer to function in harmony with each other.

Features of the adder assembly:

1. The circuit is based on film capacitor devices. This option is optimal for providing high power and circuits used in machine subs.
2. It is possible to use capacitor options designed for 100 pf. It is better to use ceramic parts.
3. A printed circuit board is used to create an adder chip. This option does not require preliminary adjustment and configuration. Printed circuit boards are the most compact.
4. When completing the assembly, the consumer will have in his hands a block consisting of a filter device and an adder. An amplifier of any power can be connected to such a device.

Adder circuit for amplifier

Assembling the power circuit stabilization unit

When driving at idle speed, the booster device requires no more than 1.5 amperes of current generated by the battery. To prevent battery discharge, a relay with a 12-volt voltage is installed in the car. The current parameter should be 20 amperes. A separate terminal is made to install the relay.

The terminal is connected to a separate contact on the audio system, the output should have a 12-volt voltage. This will allow you to activate the subwoofer with the multimedia complex. Additionally, two diode lighting sources are mounted on the board; they are used to control activation and shutdown. To obtain a bipolar power supply, transistor elements and zener diodes are mounted on the board. To reduce the voltage and stabilize the parameter to 15 volts, integral stabilizer elements are used.

Assembling the stabilization unit on the board

Putting all the parts together

There are two options to assemble all the parts of the device into one device:

1. Mount all components on one board. After this, they are installed in a plastic case.
2. Assemble all circuits and boards separately. The elements are connected through electrical circuits. The second option is preferable for novice users. When implementing it, you will still need a housing; it is used to protect equipment from external influences.

To protect electrical circuits from rapid heating, radiator devices are used, otherwise the amplifier may burn out.

Speaker amplifier

To complete the task of assembling an amplification device for car speakers you will need:

• computer or laptop;
• soldering iron with rosin and tin;
• jigsaw;
• a piece of plywood from which the body will be made;
• adhesive sealant;
• ruler;
• pencil or marker;
• set of terminals and plugs;
• woofer;
• processing unit;
• wire for connecting to the car radio and speakers;
• an electronic component that you can make yourself or buy a ready-made version.

Amplifier assembly diagram and step-by-step description of the process

The procedure for assembling an amplifier into a car with your own hands:

1. At the first stage, preparatory actions are performed. It is necessary to prepare all the elements for assembling the device and think over a plan for carrying out the work.
2. A ready-made circuit for an amplifier device is being created or searched for. The development of the board is done with similar components as described in the previous section. You can purchase a ready-made board or order an element from a specialist. The microcircuit is selected with protection against overheating and short circuit; holes are drilled on it for mounting the component elements.
3. In accordance with the diagram, the electronic component is assembled. Capacitor devices, stabilizers and other electrical components are installed.
4. After assembling the board, the housing for the amplifier is manufactured. On a piece of plywood, the walls, bottom and upper part of the body are drawn using a pencil and a ruler. Pieces of wood are cut out with a jigsaw and fixed together using sealant or self-tapping screws.
5. A woofer, electronic part, and switching devices are fixed on the device body. All electrical circuits of the speaker system must be tightly fixed in the housing and ensure their tightness in order to prevent the negative impact of external factors.
6. The amplifier device is being tested. If required, additional adjustments of the car radio parameters are made. At the final stage, the amplifier is installed in the designated place, then the operation of the acoustics is checked.

Circuit diagram of a low-power amplifier device for speakers

Rating of the best amplifiers for cars 2018

Not every consumer is able to assemble an amplification device in a garage. By purchasing a branded amplifier, the car owner receives a guarantee that the equipment will work efficiently, which cannot be said about self-made devices.

Pioneer GM-D8601

The Pioneer GM-D8601 model is made in a small case, which will ensure ease of installation of the device in a car. The single-channel device belongs to category D and is characterized by high stability to low output impedance. This allows for approximately 300 watts of power at 3 ohms. If the resistance value drops to 2 Ohms, then the rated power value will be 500 W. The price of the amplifier is 7590 rubles.

In reviews, consumers complain about an increased harmonic distortion parameter, which amounts to up to 0.5%. In fact, this does not particularly affect the sound quality, since amplification devices are used to work with subwoofers.

Advantages of GM-D8601 models:

• high power, which is confirmed by consumer reviews;
• the optimal range of reproduced frequencies is from 10 to 240 Hz;
• the device is equipped with a high-quality filter element for low frequencies;
• small body dimensions;
• using the model provides the ability to connect up to four subs;
• large outputs for connecting the power supply circuit;
• low resistance of 1 ohm.

The main disadvantages include the lack of heat sinks, which will cause the amplifier to overheat, as well as the lack of customization options.

You can learn more about this model from the video of the Autosound Factory channel.

Pioneer GM-D9601

The single-channel model allows you to connect up to four subwoofers, which allows you to squeeze maximum power out of the latter. With a resistance value of 2 ohms, the device can produce up to 1600 W of maximum power. If the operating parameter is doubled, then the peak power will decrease to 1000 W. In the case of the nominal indicator, the operating value will be 800 W at 2 Ohms of resistance.

The Pioneer model GM-D9601 is equipped with a low-pass filtering device that operates at 40-240 Hz. The main feature of a D-category amplifier, whose distortion is no more than 0.5%, is the presence of a remote bass control. This model is optimal for lovers of low frequencies.

Advantages of the model:

• availability of short circuit protection;
• the power parameter is increased to maximum values;
• high-quality low-frequency filtering device;
• working with several subs is allowed;
• small dimensions of the case, allowing installation of the amplifier anywhere in the cabin;
• presence of a regulator for changing the bass volume;
• The device consumes a minimum of electricity during operation, which prevents rapid battery drain.

The main disadvantages include the inflated cost, which amounts to 11,499 rubles.

Mystery MR-2.75

The Mystery MP-2.75 model has a low cost, but the power of this amplifier is low. The device is designed to work with a two-channel speaker system. Its use will provide deep low frequencies. Small sizes allow you to install the device almost anywhere in the cabin. The equipment belongs to the AB category, so it is characterized by increased energy consumption when the radio is activated at full power.

Advantages of the model:

• a high-quality two-channel sound system is implemented;
• availability of protection against voltage surges and short circuits;
• if the connection of the device to the subwoofer or speakers is bridged, then the power parameter can be up to 225 W;
• it is possible to adjust low frequencies;
• the presence of filter elements for bass and high frequencies;
• the harmonic distortion coefficient parameter is 0.03%;
• high range of playable frequencies, ranging from 20 to 20 thousand Hz;
• an affordable price for many car owners of about 3,599 rubles.

Cons of Mystery MP-2.75:

• the rated power value with a resistance of 2 Ohms will be no more than 120 W for one channel;
• connectors and plugs that are inconvenient to connect;
• high electricity consumption;
• minimum settings.

More details about the technical features and functionality of the Mystery MP-2.75 model can be found in the video filmed by the TAZavod 42 channel.

Pioneer GM-A5702

The cost of this device model is quite high - 7910 rubles, but the Pioneer GM-A5702 fully justifies the price. The rated power at a resistance of 4 Ohms is 150 W for each channel. When connecting equipment via a bridge circuit with a similar resistance value, the power value will increase to 1000 W. If this Pioneer model is installed in a car equipped with high-quality acoustics, it will be able to produce deep low frequencies and clear sound in general.

The model works with harmonic distortion, but this parameter is no more than 0.05%. It is possible to independently adjust the bass. As a result of the fact that the device belongs to the AB category, when operating at full power, the load on the battery will be high.

Advantages:

• the presence of a low-pass filter operating in the range from 40 to 500 Hz;
• the possibility of maximum sound reproduction at a frequency of 70 thousand hertz, sound quality depends on the installed audio system;
• the maximum power value at a resistance of 4 ohms will be 300 W per channel;
• good value of rated power, ensuring high-quality playback;
• the presence of a two-channel system, its implementation at the highest level;
• minimum amount of harmonic distortion;
• presence of a low-frequency regulator;
• compact dimensions of the device.

The disadvantages of the model include the absence of a high-frequency filter device.

Kicx RTS 4,100

This model costs 7,790 rubles. allows you to “squeeze” the maximum out of car speakers and subwoofer. It is possible to bridge the device, as a result of which the number of channels is reduced to 2, but the power value of each will be 190 W. The nominal power parameter at a resistance of 4 Ohms is 100 W for each channel. If the resistance is 2 Ohms, then the operating parameter will increase to 200 W.

Generally specifications no different from other models. This device reproduces sound at a frequency in the range of 20-20000 Hz. The consumer has the opportunity to activate the Bass Boost option, which allows you to increase the low-frequency parameter. There is a built-in crossover, and the low-pass filter device is complemented by a filter element for higher frequencies. There is protection against power surges, overheating and short circuits; safety devices rated at 35 amperes are used for protection.

Advantages of the Kicx RTS 4.100 model:

• high power value for multi-channel equipment;
• small dimensions allowing for simplified installation;
• various options for protecting the device from failure;
• possibility of amplification of low frequencies;
• presence of a crossover;
• reduced harmonic distortion parameter.

This model has no disadvantages, but some consumers note a lack of equipment power.

Team Sound Quality Rtishevo channel led detailed review characteristics and features of the Kicx RTS 4.100 car amplifier.

Sony XM-S400D

Consumers trust the Sony brand because this company made a name for itself in the production of audio equipment. The Sony XM-S400D model is characterized by increased reliability and compact dimensions. Users do not like the design of the device, which is made in the form of a regular black box with several outlets on the sides. But this drawback is insignificant, since no one will look at the device during operation.

Installing an amplifier in a car will provide deep and accurate sound, which is due to the presence of filtering devices for all types of frequencies. The rated power parameter is 45 W for each channel, provided that the resistance value is 4 Ohms. If the connection type is bridged, then the power will increase to 100 W for each channel, while the number of channels will not decrease. Features of the device include reduced harmonic distortion of 0.08%. Due to the fact that the model belongs to category D, the amplifier consumes a minimum of electricity during operation.

Advantages of the model:

• high rated power;
• obtaining deep and clear sound when connecting an amplifier;
• the ability to reproduce frequencies over a wide range;
• the presence of filtering components that provide high-quality sound;
• reliable protection of equipment from failure; various systems are used for this.

Cons of Sony XM-S400D:

• lack of ability to adjust low frequencies;
• consumers note the difficulties that may be encountered when installing equipment;
• high price - 9990 rub.

Complete set of amplifier model Sony XM-S400D

Genesis Profile Four Ultra

This model costs 18,990 rubles. cannot boast of an original design, but it looks quite elegant, which is achieved thanks to the narrow radiator devices installed inside. The maximum power setting can be up to 400 W, which is quite enough to set up a loud audio system. The presence of a fan will provide effective protection of equipment from overheating, and thanks to the crossover, unnecessary frequencies can be removed. The Genesis Profile Four Ultra model is considered the best option for installation in a car where front speakers play.

Advantages of the Genesis Profile Four Ultra amplifier:

• increased equipment power;
• possibility of functioning with a regulatory device;
• using a bass equalizer that allows you to adjust parameters;
• the presence of a fan inside the structure;
• small body dimensions.

Disadvantages include the sensitivity range. Some consumers note that it is not as extensive as it could be.

Audison SR 4

This model costs 21,700 rubles. It is considered universal and, judging by reviews, has a long service life. When developing the device, the manufacturer implemented a configuration configured for the most commonly used circuit, which will eliminate installation problems. The device is enclosed in an aluminum housing, which prevents physical damage to the equipment. The developer used a competent design in manufacturing, which ensures high-quality cooling of the device. The functionality that this model has indicates the need to install an amplifier on a front speaker system with a subwoofer.

Advantages of the Audison SR 4 model:

• Durable aluminum housing ensures long-term operation of the device;
• the ability to flexibly customize the device to suit specific needs;
• ease of equipment management;
• effective cooling system that prevents the device from overheating.

Flaws:

• the model cannot boast of small dimensions, difficulties arise when installing the device;
• no bandpass filter device.

The Avtozvuk channel in the video gave detailed advice on adjusting the basic parameters and tuning the car amplifier after installation.