Serial and parallel connection of speakers. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Serial and parallel connection of speakers. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Speakers

Comments on the article

It is good if the installer has the opportunity to apply a channel-by-channel amplification scheme. However, in most cases this is considered an unaffordable luxury, and in the process of installing an audio system, in nine cases out of ten, there is a need to load, for example, a two-channel device with four speakers or a four-channel device with eight.

Series and parallel connection of speakers

Actually, there is nothing terrible in this. It is only important to keep in mind a few basic ways to connect speakers. Not even a few, but only two: serial and parallel. The third - series-parallel - is the derivative of the two listed. In other words, if you have more than one speaker per channel of amplification and you know what loads the device can handle, then choosing one, the most acceptable scheme from three possible ones, is not so difficult.

Series connection of speakers

It is clear that when the drivers are connected in series, the load resistance increases. It is also clear that with an increase in the number of links, it grows. Usually the need to increase the resistance arises to reduce the output performance of acoustics. In particular, when installing a rear sub-sound or a center channel speaker, which mainly perform an auxiliary role, they do not require significant power from the amplifier. In principle, you can connect as many speakers as you like in series, but their total resistance should not exceed 16 ohms: there are few amplifiers that work with higher loads.

Figure 1 shows how two dynamic heads are connected in a daisy chain. The positive output connector of the amplifier channel is connected to the positive terminal of speaker A, and the "minus" of the same driver is connected to the "plus" of speaker B. After that, the negative terminal of speaker B is connected to the negative output of the same amplification channel. The second channel is built according to the same scheme.

These are two speakers. If you want to connect in series, say, four loudspeakers, then the method is similar. The “minus” of speaker B, instead of being connected to the output of the amplifier, is connected to the “plus” C. Further from the negative terminal C, a wire is thrown to the “plus” D, and already from the “minus” D, it is connected to the negative output connector of the amplifier.

Calculating the equivalent load resistance of an amplification channel loaded with a string of series-connected speakers is done by simple addition using the following formula: Zt = Za + Zb, where Zt is the equivalent load resistance, and Za and Zb are the resistances of speakers A and B, respectively. Ohm and less) loads. In this case, connecting the woofers in series is the only possible option. Each amplification channel serves a pair of heads with a total resistance of 12 ohms, which easily fits into the above 4 ohm frames. Whereas the parallel connection of the speakers (about it later) will lead to an unacceptable (less than 2 ohms) decrease in the load resistance of both channels and, as a result, the failure of the amplifier.

When more than one speaker is connected in series to the same amplification channel, output power is inevitably affected. Let's return to the example with two 12-inch drivers connected in series and one 200-watt stereo amplifier, the minimum load impedance of which is 4 ohms. To find out how many watts the amplifier can give to the speakers under such conditions, you need to solve another simple equation: Po = Pr x (Zr / Zt), where Po is the input power, Pr is the measured power of the amplifier, Zr is the load resistance at which the real power of the amplifier was measured, Zt is the total resistance of the speakers loaded on this channel. In our case, it turns out: Po = 100 x (4/8). That is 50 watts. We have two speakers, so the "fifty kopeck" is divided into two. As a result, each head will receive 25 watts.

Parallel speaker connection

Here everything is exactly the opposite: with a parallel connection, the load resistance drops in proportion to the number of speakers. Accordingly, the output power increases. The number of loudspeakers is limited by the ability of the amplifier to operate at low loads and by the power limits of the loudspeakers themselves connected in parallel. In most cases, amplifiers can handle loads of 2 ohms, less often 1 ohm. There are devices that can handle even 0,5 ohms, but this is really a rarity. As for modern loudspeakers, there is a spread in power parameters from tens to hundreds of watts.

Figure 2 shows how to connect a pair of drivers in parallel. The wire from the positive output connector is connected to the positive terminals of speakers A and B (the easiest way is to first connect the amplifier output to the “plus” of speaker A, and then pull the wire from it to speaker B). In the same way, the negative output of the amplifier is connected to the "minuses" of both speakers.

Calculating the equivalent load resistance of an amplification channel when the speakers are connected in parallel is somewhat more complicated. The formula is: Zt = (Za x Zb) / (Za + Zb), where Zt is the equivalent load resistance and Za and Zb are the speaker impedance.

Now let's imagine that a 2-channel device (2 x 100 W for a load of 4 ohms) is again assigned to the low-frequency link in the system, but it works stably at 2 ohms. Connecting two 4 ohm subwoofer drivers in parallel will significantly increase the output power, since the load resistance of the amplifier channel will be halved. According to our formula, we get: Zt = (4 + 4) / (4 + 4). As a result, we have 2 ohms, which, provided that the amplifier has a good current margin, will give a 4-fold increase in power per channel: Po = 100 x (4/2). Or 200 watts per channel instead of the 50 you get when you connect speakers in series.

Series-parallel connection of speakers

Typically, this scheme is used to increase the number of speakers on board the vehicle in order to achieve an increase in the total power of the audio system while maintaining adequate load impedance. That is, as many speakers as you like can be used per channel of amplification, if their total resistance is within the limits already indicated by us from 2 to 16 ohms.

Connecting, for example, 4 speakers using this method is as follows. The cable from the positive output of the amplifier is connected to the positive terminals of speakers A and C. Then the negatives of A and C are connected to the positives of loudspeakers B and D, respectively. Finally, the cable from the negative output of the amplifier is connected to the negative terminals of speakers B and D.

To calculate the total load resistance of an amplification channel that works with four heads connected in a combinatorial way, the following formula is used: Zt = (Zab x Zcd) / (Zab x Zcd), where Zab is the total resistance of speakers A and B, and Zcd is the total resistance of speakers C and D (they are connected to each other in series, so the resistance is summed up).

Let's take the same example with a 2-channel amplifier running stable at 2 ohms. Only this time, two 4-ohm subwoofers connected in parallel do not suit us anymore, and we want to connect 4 woofers (also 4-ohm) to one amplification channel. To do this, we need to know whether the device can withstand such a load. With a serial connection, the total resistance will be 16 ohms, which does not suit anyone. With parallel - 1 Ohm, which no longer fits into the parameters of the amplifier. What remains is a series-parallel circuit. Simple calculations show that in our case one amplification channel will be loaded with standard 4 ohms, pumping four subwoofers at once. Since 4 ohms is a standard load for any car power amplifier, no losses and gains in power indicators will occur in this case. In our case, that's 100 watts per channel, evenly divided into four 4-ohm speakers.

Let's sum up. The main thing when building such schemes is not to overdo it. First of all, with regard to the minimum load of the amplifier. Most modern devices can handle 2-ohm loads quite well. However, this does not mean at all that they will work at 1 Ohm. In addition, at low loads, the amplifier's ability to control the movement of the speaker cone is reduced, which most often results in "blurred" bass.

All three examples above dealt exclusively with the low-frequency link of the audio complex. On the other hand, theoretically, on one two-channel device, you can build the entire speaker system in a car with mid-bass, mid-range and tweeters. That is, with speakers playing in different areas of the frequency spectrum. Therefore, passive crossovers will have to be used. It is important to remember here that their elements - capacitors and inductors - must be matched with the equivalent load resistance of a given amplification channel. In addition, the filters themselves introduce resistance. In this case, the farther the signal is from the passband of the filters, the greater the resistance.

Author: A. Krasner; Publication: 12voltsmagazine.com

See other articles Section Speakers.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

Efficient artificial photosynthesis 18.11.2022

A team of chemists has developed an artificial photosynthesis system many times more efficient than any current solution. It can produce ethanol, methane or other fuel. Through this process, we may soon be fueling cars.

In nature, photosynthesis is carried out by several complex complexes and systems that are difficult to direct to perform other tasks. They take in water and carbon dioxide, break down molecules, and redistribute atoms to make carbohydrates. Over the production of methane instead of them, chemists have been fighting for decades. A group of scientists from the University of Chicago decided to add to the reaction something that is not found in natural photosynthesis - amino acids.

It is based on metal-organic framework structures (MOFs), a class of materials made of metal ions bound by organic molecules. Then a layer was created from it, which became a surface for chemical reactions, and it was immersed in a solution with cobalt. Finally, amino acids were added.

The result showed that both halves of the reaction can be improved in this way: the process of splitting water and the process of combining electrons and protons with carbon dioxide. In both cases, the amino acids increased the efficiency of the reaction by one order of magnitude compared to similar methods.

Artificial photosynthesis has a long way to go before it can produce enough fuel to be relevant for widespread use. However, this is an important step in the right direction. In addition, the discovery can be applied to other chemical reactions, such as pharmaceuticals or the production of nylon.

Other interesting news:

▪ Smart ring for women Evie

▪ ASUS PA32Q Professional 4" 328K Monitor

▪ apple ipad

▪ Magnetic heads polished with green tea

▪ Eternal microgravure on diamond

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Tools and mechanisms for agriculture. Article selection

▪ article Rubakin Nikolai Alexandrovich. Famous aphorisms

▪ article Where could I visit the Church of St. James Bond? Detailed answer

▪ article Teacher-defectologist. Job description