Automotive topics, like no other, are especially close to most of the male population of our vast Motherland. Many of us spend a lot of time and money, bringing our "iron friend" to the maximum possible perfection. This is especially true when it comes to car music and acoustics. In addition, we always want to try to save some money by doing at least part of the work with our own hands. Moreover, everyone ever does something for the first time. But once again we remind that it’s better to measure it seven times before undertaking anything. This approach will save you a lot of time and money.
Today we’ll talk about how to connect an amplifier in a car. We believe that this topic will be of interest to you.
Suppose that you have already managed not only to choose a suitable model, but also to clear a place for installation in your car. Now we have to make good wiring to power the amplifier, then connect it to the acoustics, and also throw the cable to the radio itself. However, let's talk about everything in more detail.
We power up the amplifier
Newcomers who first encounter car sound are amazed to the core by the thickness of wires, which is rarely seen in everyday life (well, unless you are used to using welding machines or something like that in this case, then this parameter will not surprise you).
Contrary to common misconceptions, amplifiers consume decent currents from the on-board network. So, a four-channel device with 50 watts per channel will consume almost 17 A. Not bad, is it? Of course, that for the power supply will have to use wires with a really large cross section. So before you connect the amplifier in the car, visit specialized stores.
Classic version
Let's analyze the classic connection diagram. In this case, the wiring directly clings to the car battery. It's no secret that in most cases the battery is located under the hood, while the amplifier is located inside the car. Accordingly, the positive cable goes through almost the entire interior of the car. And therefore it is extremely important to protect the wiring with a high-quality fuse, and it should be located no further than 30 cm from the battery.
So before you connect the amplifier in the car, visit the electronics store and buy a normal fuse.
A bit about isolation
In addition, do not forget to additionally insulate the cable, since from 17 A jokes are bad. Particularly carefully, protect the space between the engine compartment and the passenger compartment, as the cable is often frayed there. As a rule, there is a rubber gasket, but there are exceptions. If so, it does not hurt to use plastic sleeves made of durable and thick enough plastic. Responsibly approach this issue, since it is clearly not worth it to allow exposed frayed cable to hit the body metal!
The wire through the cabin must also be pulled, preventing it from falling under its moving parts. There were times when people threw a cable under the seat rails. What consequences this can lead to, you can come up with yourself. So how to connect the amplifier in the car?
Choose a cable
Do not forget about the golden rule: the fewer connections, the higher the security! The abundance of wires with different cross sections is fraught with high energy losses, and from the point of view of fire safety this does not look the best way.
In addition, the cross section of the negative wire should be equal to that of the positive cable. The current in the network is one, its value is constant. If the wires have a different cross-section, they will overheat, which again is fraught with a fire in the car.
Once again, thin cords are high resistance. In no case do not save on cables that go from the battery to the amplifiers, as we have already talked about the strength of the current that passes through them.
A bit of physics and mathematics
First, check what is the maximum current consumption of the amplifier you use. To do this, look at the fuse (or fuses). Suppose your amplifier can theoretically withstand 100 A. immediately. It is better to place it in the trunk. For a typical car, it is preferable to take at least five meters.
I = 100 A; L = 5 m.
Even under the condition of maximum current use, the voltage drop at the positive end of the wire should not exceed 0.5 V. We recall the simplest school formula for calculating resistance, after which we carry out a simple calculation:
R total = U / I = 0, 5 V / 100 A = 0, 005 Ohms.
Thus, the cable resistance should not exceed 0, 005 Ohms. Since we plan to use five meters at once, it is necessary to calculate the resistance on a segment in meter:
R meter = R Total / L = 0, 005/5 = 0, 001 Ohms.
As you can see, we need a wire with running resistance not higher than 0, 001 Ohm / m. And now you can take a catalog of any manufacturer, and then choose something suitable.
Cable connection
After you lay the wire in the cabin, you can connect it to the positive terminal of the amplifier. The negative cable is connected directly to the body, and for this you need to use an instance with the same cross section as the plus. In no case do not resort to the help of self-tapping screws! You can fasten only with bolts, and the connection point must be cleaned as high as possible from traces of paint and other contaminants.
The battery positive lead should be connected to the + 12V terminal, and the negative lead to GND (ground - ground, ground). Before connecting the amplifier to the radio, find the remote contact, because it is designed to hook the wire that just comes from it. It is in it that the very 12Vs appear, and therefore the radio tape recorder can control the functions of the amplifier. Most often, this cable is blue (or blue with a white stripe). It would be nice to install a capacitor in the system as well.
Pull the cable from the radio
We continue to analyze the question: "How to connect the amplifier to the radio?" Now we need to lay a cable through which the signal will go from the player to the amplifier. Typically, it comes from a Line Out, indicated by “bells” on the rear panel.
We draw your attention to the fact that the radio tape recorders of different models and from different manufacturers can have a different number of line outputs. Most often there are three pairs, but in professional players there are more. These are the following outputs: Front, Rear and Sub, designed to connect front, rear sound systems, as well as a subwoofer. Which one you need depends on which amplifier you purchased in the car.
All this is connected by an interconnect cable, which is distinguished by reinforced shielding. In fact, the choice of such a wire is quite pulling on the topic of a separate article, so we will limit ourselves to one piece of advice. In no case do not save on it; purchase products only from well-known and reliable suppliers.
Before connecting the amplifier to the car radio, it will not be superfluous to also read the instruction manual. This will help you avoid many problems.
Connect the cable to control the amplifier
We already said that it is necessary to lay wires to control the amplifier itself. By the way, it is advisable to do this by laying interconnect wire. Moreover, in many models there is a special cable for this purpose. At one end it is attached to the amplifier (once again we remind that it is painted in blue or blue-white), and the other to the radio. Tip: when buying an amplifier in a car, be sure to purchase all the wires with it, as it is better to immediately consult the seller about them.
It is not necessary to buy a cable with a large cross-section, since very small currents will pass through it.
Very important notes
Extremely important note: in no case do not lay the interconnect wire near power cables! For example, if the power wiring is on the right through the cabin, then the control wires should pass on the left, as long as possible from the power !!!
In addition, you can stretch them under the floor mats, as in this case there is a maximum probability of not “catching” the interference. If you decide on world stupidity, laying all the wires back to back, then when the engine is running, you will listen to crackles, howls and other noises in the speakers. There will be no other way but to completely redo all the work. Since connecting an amplifier to a car is a long and tedious job, you should not rush.
In especially severe cases, the wires still have to be pulled under the ceiling, masking them under the upholstery. This is especially true for ultramodern cars that are literally "stuffed" with various kinds of electronics. In this case, there is so much interference that sometimes you have to use special shielding.
Differences in connecting different types of amplifiers
If you put a two-channel amplifier, then you need a similar interconnect cable. If four-channel - a pair of double wires, or a special four-channel.
And how to connect the amplifier to the radio, if it has only a couple of linear outputs, and the amplifier itself is four-channel? In this case, special Y-adapters (splitters) can help you. Cunning Chinese have created a device that provides a pair of outputs for each input. Thus, from one stereo pair we get two at once. Convenient, you will not say anything. Of course, doing this with acoustics of the highest price category is not worth it, since the sound quality is noticeably reduced.
There is another way. All normal models of modern amplifiers (Audison, for example) are equipped with an internal parallel distribution of inputs. In a word, in this case you will not need any splitters.
If your radio does not have linear outputs at all, then it can be connected directly to the speakers (high-level signal). Almost all normal devices currently have corresponding terminals (Hi level input). For connection, the most ordinary acoustic wires are used, and it would be better not to mix up the poles.
We connect a single - channel amplifier (aka a monoblock)
Single-channel amplifiers have only one function - connecting to a subwoofer. They have a very decent power, and also have the ability to work under low resistance load. What is it, by the way? In ordinary car speakers, the impedance is only 4 ohms, and all other equipment has much lower characteristics (3 ohms, 2 ohms, 1 ohms). This is called a low-impedance load. All these amplifiers belong to the D-class.
Today they all have a built-in LPF filter that cuts all frequencies above those that you set as maximum for the subwoofer. The scheme for connecting it to disgrace is simple. Subwoofers are connected in parallel or in series, or only one speaker is mounted. At the same time, you can connect even more than two low-frequency speakers at once, but it is important to consider that not all subwoofer models can cope with significantly increased resistance.
Here is the simplest and most common installation diagram. The linear signal from the radio goes to the amplifier, is summed and amplified. The wiring diagram for the control and transmission wires should be found in the instructions from your manufacturer.
How to connect a two-channel amplifier?
And now we will learn how to connect the amplifier to the radio, if it is a two-channel model. Devices of this type are for many a launching pad in the world of car audio. This is explained not only by low cost, but also by simplicity. These amplifiers are often used to connect to a front speaker system or subwoofer. Let's talk about each of these options.
Connecting front speakers
If you plan to use the amplifier to “swing” the front or rear speakers, it is connected in stereo mode. So how to connect a two-channel amplifier?
The signal is low or high. It is advisable to connect a low-pass filter (HPF), which is especially important in this installation scheme. In this case, the load on each amplifier can reach up to 2 ohms. Thus, on each channel you can hang one speaker system at 4 ohms.
Subwoofer connection
Very often there is a device connected by the so-called "bridge" option. Before connecting the subwoofer to the amplifier, make sure the device is “fresh”: almost all new models make excellent use of this mode. Accordingly, their instructions contain detailed diagrams that clearly demonstrate where and how to connect the plus and minus wires. In this case, the power is summed up, and the sound is more rich and rich.
In addition, there are icons on the rear panel indicating the connectors for the power cable, grounding, as well as a compartment for wires to the speakers. It’s easy to figure it out. Here's how to connect a sub to an amplifier. Not too problematic, is it?
Other models have a special switch with which you can put the equipment in mono mode. It is very important: when using the bridge mode, remember that in this case almost all the “amplifiers”, with rare exceptions, will not work under a load of less than 4 ohms! Before connecting the subwoofer to the amplifier, the latter must include the LPF filter. Otherwise, all frequencies above 50-100 Hz will go to the subwoofer, and this will hopelessly ruin the sound. This is surely not even like people who are not all right with a musical ear.
Four channels!
How to connect a 4-channel amplifier? In general, in this case, there is absolutely nothing complicated. We pull the positive cable from the battery, following the above instructions (we take the wire thicker and as high as possible).
Line outputs on the radio (RCA - tulips) should be four pieces. If there are 2 of them, we buy a splitter, which we already mentioned above. Line-ups are connected to the player and amplifier. When you are going to connect the amplifier to the head unit, do not forget to disconnect the battery, as you can burn fuses.
Then the control cable (remote) is drawn between the audio recorder and the amplifier. As we have already said, it is very thin and extremely in need of high-quality shielding. Then the acoustics are connected, its adjustment is carried out.
How to connect a single-channel amplifier?
This kind of technique is the actual connection in one case of single and dual channel models. Accordingly, you can connect several subwoofers to it, and “hang” the front and rear speakers to the remaining outputs (marked with the corresponding icons).
How to mount multiple amplifiers?
How to connect two amplifiers? If you plan to install several blocks of this nature in a machine at once, there are two ways to do this. The first is just to pull one thick cable from the battery, and then through the splitter to put current into the amplifiers. Note! If the wires are longer than 40 centimeters and also have a smaller (compared to the main cable) diameter, it is extremely important to protect them with fuses.
Option number two. Pull as many wires from the battery as you have amplifiers installed. Despite the apparent technological complexity of such a solution, in practice it is not so scary. The fact is that a couple of relatively thin wires are much easier to throw than one thick one. And most importantly: in this situation, you only need to think about how to connect 2 amplifiers. And you don’t have to worry about fuses at all.
Pull the wires to the speaker system
Let's talk about the features of connecting amplifiers and speakers. As we have repeatedly mentioned, for this it is necessary to use special wires. They can be pulled without fear of interference from other electronics in the car. But on the crossovers, acoustic “pick-ups” are quite realistic to catch, so the cable should be located as far as possible from sources of probable interference.
There is only one difficulty. It's about pulling the cable in the door. So how to connect the amplifier to the speakers?In most cases, manufacturers do not forget about consumers, leaving special connectors for laying cable channels or embedding rubber couplings under them. But often this kind of gifts from the car industry can not wait, and therefore have to drill additional holes.
Do not forget to remove the terminals from the battery before starting work!
Other tips
If you carefully read the article, then you must have repeatedly seen references to fuses. Which models are best used to protect the system?
The head unit can be protected from combustion by a conventional flag fuse. Since it is located directly under the hood, you need to buy a holder in the most moisture-resistant design. For medium power systems, fuses of the AGU type are perfectly suited, having a characteristic appearance resembling large round cones.
But powerful speakers are much more appropriate to protect with ANL elements (they are flat, in the form of tablets). As an alternative to such devices, you can take circuit breakers, which immediately turn off the system in the event of a short circuit or a sharp increase in voltage. By following these tips, you will keep your equipment in top condition!
So we looked at how to connect the amplifier to the speakers. Read the instructions carefully and choose the right wires! Good luck!