Modernization of a car's standard audio system often begins with replacing the head unit with a modern Android radio radio format 2 Din. However, even the most advanced device will not be able to unlock the potential of high-quality acoustics without external amplification. The built-in amplifiers of radio tape recorders, as a rule, produce about 18-25 watts per channel, which is not enough to create deep bass and clear high frequencies at high volumes.
The process of integrating an external amplifier requires an understanding of the electrical circuit of the car and the correct selection of switching. Errors at the connection stage can lead not only to poor sound, but also to the failure of expensive equipment or a wiring fire. In this article, we will analyze in detail the connection steps, the choice of wires and the subtleties of setting up the system to achieve ideal sound.
Selection of equipment and preparation of tools
Before starting installation work, you need to make sure that the selected amplifier is compatible with your audio system. Modern Android radios equipped with standard linear outputs RCAwhich are ideal for transmitting a signal to a power amplifier. It is important to check the number of channels: for full sound in a car, you usually need a four-channel amplifier or a combination of a two-channel and a monoblock for a subwoofer.
Sound quality directly depends on the quality of the wires used. Cheap kits often have oversized markings and low conductivity, which leads to voltage drop and heating. For systems with a power of up to 500 Watt, it is recommended to use copper wire with a cross-section of at least 4 GA (about 21 mm²) for power and 8-10 GA for interconnect cables.
You will need the following set of tools and materials:
- 🔧 A set of screwdrivers and keys for dismantling the panel and battery terminals.
- ✂️ Special wire cutters for stripping wires and crimping pliers.
- 📏 Multimeter for checking voltage and finding ground.
- 🔌 Set of installation wires (Power Kit) of the appropriate cross-section.
⚠️ Attention: Before starting any work with electrical wiring, be sure to disconnect the negative terminal of the battery. A short circuit of the positive wire to the body can cause sparking and damage to the car's electronics.
Amplifier power connection diagram
The most critical step is laying the power cable from the battery to the amplifier installation location. The current consumed by a powerful amplifier can reach tens of amperes, so the connection must be reliable. The power cable is laid along the standard wiring of the car, usually under plastic thresholds or through holes in the engine panel.
A fuse must be installed at the gap in the positive wire, at a distance of no more than 30 cm from the battery terminal. This is a critical safety feature: if the cable is damaged by the metal edge of the body, the fuse will blow, preventing a fire. The fuse rating is selected based on the maximum power of the amplifier using the formula: Current = Power / Voltage.
☑️ Checking the power line
The negative wire (Ground) should be as short as possible and connected directly to the car body at a point with good paint contact. The mounting location must be cleaned down to metal and treated with contact lubricant to prevent oxidation. A bad ground is the most common cause of hum and hum in an audio system.
Organization of interconnection
The transmission of the audio signal from the head unit to the amplifier is carried out through shielded interconnect cables RCA. It is extremely important to route these cables on the opposite side of the cabin from the power supply wire. Parallel routing of power and signal wires can cause interference, which will manifest itself in the form of an unpleasant hum or whistle when the engine is running.
On the rear panel Android 2 Din radios find the connectors labeled Audio Out, Pre-Out or RCA Out. Typically they are coded: white and gray for the front channels, green and purple for the rear, and an orange or separate connector for the subwoofer. Connect the cables according to the color coding or diagram in the instructions.
Use interconnect cables with double shielding and gold-plated connectors - this will significantly reduce the level of external interference and improve sound detail.
If your radio has only one output on subwoofer and amplifier requires a stereo signal for this channel, use a Y-adapter. For four-channel amplifiers operating in bridge mode, it is important to observe the polarity of connecting the speakers, which will be discussed below.
Connecting the Remote control wire
To automatically turn the amplifier on and off together with the radio, a thin control wire is used, marked as Remote or REM. When you turn on the ignition or radio, +12V voltage appears on this wire, which activates the amplifier's power circuit. Without this connection, the amplifier will work constantly, draining the battery.
In standard wire sets, this cable is usually blue or blue-white. It must be connected to the corresponding connector on the amplifier. If the length of the standard wire is not enough, it can be extended with any multi-core wire of small cross-section, since the current in this circuit is minimal.
| Wire color | Purpose | Where to connect |
|---|---|---|
| Red / Yellow | Constant plus (+12V) | Battery (via fuse) |
| Black | Ground (GND) | Car body (bolt) |
| Blue / White | Control (Remote) | REM connector on the amplifier |
| Transparent / Color | Acoustic output | Speaker terminals amplifier |
Some users mistakenly connect the wire Remote to the antenna power wire. Although this often works, it is more correct to use a dedicated output from the radio to avoid conflicts in the electrical operation, especially if the antenna has active amplification.
Switching speaker wires and bridging
Connecting speakers to the amplifier requires attention to polarity. Compliance with phasing (Plus k Plus, Minus k Minus) is critical for the correct formation of the sound wave. If the polarity is violated, the bass becomes sluggish and the sound stage “falls apart.”
To increase power, a bridge connection is often used (Bridged Mode). In this mode, one amplifier channel operates on the positive half-wave of the signal, and the second on the negative half-wave. This allows you to get significantly more power per speaker, for example, for a subwoofer. However, in this mode, the load impedance (resistance) doubles.
Danger of bridge mode
When bridged, make sure your amplifier can handle a 2 Ohm load in the bridge. Connecting a 1-Ohm load to the bridge can lead to overheating and tripping of the protection or damage to the output transistors.
Use special acoustic terminals or twist the wires securely, insulating the connections with heat shrink. Avoid hanging twists, which can oxidize due to vibration. The wires must be laid so that they do not rub against moving parts or sharp metal edges.
⚠️ Attention: Never connect the negative wires of different speakers to each other or to the body if the amplifier is not operating in bridge mode. This will lead to a short circuit in the output stages of the amplifier.
Initial setup and elimination of interference
After physically connecting all the wires and checking the reliability of the contacts, you can begin setup. Turn on the radio and make sure that the amplifier's power indicator lights up. First of all, set the knob Gain (input level) on the amplifier to the minimum position.
On Android radio tape recorder go to the sound settings (Settings → Car Settings → Sound). Disable all built-in effects, equalizers and bass boosters by setting them to "Flat" or "0". This is necessary in order to supply a clean signal without distortion to the amplifier.
The process of setting the level Gain looks like this:
- 🎵 Turn on a track with loud but undistorted music on the radio tape recorder (volume 75-80% of the maximum).
- 🔊 Slowly rotate the Gain knob on the amplifier until the first signs of wheezing appear.
- 🔙 As soon as you hear distortion, slightly reduce the Gain back to a clean sound.
If after starting the system you hear a constant low-frequency hum, check the ground connection point. Often the problem is solved by moving the negative wire to another location on the body or using a thicker wire. Also make sure that the interconnect cables are not lying next to the power wires.
Software configuration of sound in Android
Modern radios based on Android provide ample opportunities for digital sound processing. After setting the Gain analoguely, you can use the built-in equalizer. For a high-quality system, it is recommended to use a parametric equalizer, if it is available in the firmware.
In the settings menu, find the section DSP or Sound Effect. Here you can set time delays (Time Alignment) so that the sound from all speakers reaches the listener at the same time, creating the effect of a stage in front of the windshield. This is especially true for driver-oriented systems.
Correctly setting the time delays is more important than just cranking up the bass. It creates surround sound and localization of instruments, which cannot be done only by adjusting the volume.
If the standard functionality is not enough, you can install third-party applications from Google Play, such as Viper4Android (Root access required) or specialized players with an advanced equalizer. However, remember that digital signal amplification can lead to clipping if the input level to the amplifier is already set to the limit.
Is it possible to connect the amplifier without a Remote wire?
Technically it is possible by connecting the control wire to the positive ignition terminal, but this is not recommended. The amplifier will only turn on when you turn the key, and not when you turn on the radio, which is inconvenient. In addition, this creates an extra load on the ignition circuit.
Why does the amplifier go into protection when turned on?
Most often this happens due to a short circuit in the speaker wires, poor grounding or resistance overload (impedance of the connected speakers is too low). Also, the reason may be a voltage drop in the on-board network.
Is a capacitor needed when connecting an amplifier?
A capacitor (1 Farad or more) is useful if the car's headlights noticeably dim when the bass hits. It smooths out peak voltage sags. For medium power systems and a working battery, its installation is not necessary.
Does the quality of the Android radio affect the sound?
Yes, it does. The quality of the built-in DAC (digital-to-analog converter) and preamplifier in the head unit determines the noise level and signal detail. Budget models may have a high level of self-noise, which the amplifier only scales.