The difference between an active subwoofer and a passive one: advantages and disadvantages. Subwoofer passive and active: what is the difference between them? Causes of Subwoofer Hearing and Not Bass

The difference between an active subwoofer and a passive one

The difference between an active subwoofer and a passive one is obvious, since both devices perform different functions. A subwoofer is a low-frequency speaker designed to reproduce a wide range of frequencies, working in conjunction with any kind of speaker system.
Knowing how an active subwoofer differs from a passive one, you can safely make your choice in favor of one or another speaker.

Types of subwoofers

For a subwoofer to work, three elements must interact. This is the body itself, the woofer and the amplifier.
Depending on this arrangement, subwoofers are divided into two types:

• Active subwoofer;

The main differences between subwoofers

A passive subwoofer is a low-frequency speaker enclosed in a special acoustic enclosure. It needs to be connected to an external amplifier for it to work.
It can also be connected using an electronic crossover filter. This arrangement allows you to achieve deeper bass and significantly expand the frequency spectrum.

Note: it should be borne in mind that linear sound distortions are significantly reduced at increased volume, so it is advisable to listen to compositions at an average sound volume.

A low-frequency subwoofer is usually complemented by a home theater system or a speaker system in a car. This allows you to achieve rich bass and split the sound.
An active subwoofer can significantly reduce the load on the receiver in a home theater system. When choosing a subwoofer, it is necessary to take into account the properties of the space where it will be installed.
The bass-reflex subwoofer has a deeper bass and is designed for a large cubic capacity of the room. In a confined space, such as in a car, this type of subwoofer may start to resonate.

Advantages and disadvantages

Each type of subwoofer has its own advantages and disadvantages due to its design features. A passive subwoofer has a deeper and richer bass than an active subwoofer.
This is due to many different factors:

• No overheating of the air inside the case;
• Possibility of connection of additional electronic filters (see);
• The external power amplifier has a large number of settings;
• Due to the absence of foreign components in the body, the power and depth of the bass becomes more saturated;
• Lower cost compared to an active subwoofer with similar specifications.

• Possibility of use as portable, if there are outputs for additional speakers;
• Various execution options.

When choosing between an active and passive subwoofer, it is worth deciding directly where it will be used and what sound characteristics are needed.

The influence of the cabinet on the sound of a subwoofer

The cabinet in the subwoofer is the main element of the speaker system. Thanks to him, you can create a directional, deaf, or diffused bass.
There are several main types of corpus:

• The closed case is a box in which the speaker is in an enclosed space. In this case, the oscillations of the speaker dampen the pressure that arises inside due to the oscillations of the cone.
  The subwoofer in the closed case gives a deep saturated bass. The body is lined on the inside with a special soundproofing material that absorbs heat and creates air pressure inside.
  The power of such a subwoofer directly depends on the internal volume of the case. But at the same time there is one drawback: the efficiency of this type of subwoofer is the smallest;
• Chassis with phase inverter. It has a special hole for air venting.
  This allows you to direct the sound wave and significantly increase the power of the subwoofer. Thanks to this, even at the lowest frequencies, the speaker works with little or no significant load.
  The sound low-frequency wave arises due to the injection of air. This type of cabinet gives a very sharp and powerful bass;
• Bandbass Corps. The speaker is located in the partition between the two chambers. This type of cabinet combines the previous two and significantly improves the quality and efficiency of sound.
  The main point is that you can simultaneously adjust the upper and lower bass levels. This allows you to make the bass richer and more natural. But this type of subwoofer is the most expensive, because it is very difficult to manufacture.

Each type of subwoofer is designed for a specific type of room. At the same time, due to the internal properties of the case and the size of the speakers, the sound directly depends.
Both subwoofers have their advantages and disadvantages, so it is better to consult with experts before choosing.
A passive subwoofer produces a larger frequency range than an active subwoofer. But there may be problems with its connection, since it is necessary to choose the right power amplifier and connect electronic sound filters.
An active subwoofer is enough to connect to a power source and give it a sound signal. You can even do it yourself, as the kit also offers instructions.
Going to the store for a purchase, you need to understand that the price of a quality device will be high. Of course, it is advisable to see photos and videos regarding the operation of different types of subwoofers in order to make your choice.

From time to time, subwoofers of the band-pass type fall into our field of view. Otherwise - bandpasses ...

Most often, it should be noted, in the form of finished products. Much less often - as an element of a system built on an individual project. The basics (quite the basics) of the theory and practice of this type of design were published with us a long time ago, years, not to lie, 15 years ago. There is an opinion (of the author) that it would be necessary to clarify something on this issue, otherwise, you see, and remind, not forgetting about “newly discovered circumstances ...”

1. Relatively narrow frequency range.

2. Increased complexity of manufacturing and customization.

We see more benefits.

1. The presence of an internal low-pass filter.

2. The ability to reproduce low bass.

3. Acoustic amplification.

4. The security of the speaker from external influences.

The first minus and the first plus are two sides of the same coin, which confirm the well-known wisdom that every thing is good in its place. That is, for the role of a broadband bass radiator (in three-way acoustics, say), the bandpass is of little use, while in the position of a subwoofer it will be very out of place. The second drawback was a factor that largely limited the spread of bandpass designs. Moreover, the problem is not even in manufacturing, after all, the difference between PP and FI lies only in the presence of an additional inner wall. The difficulty is that in the process of fine tuning one of the walls will probably have to be moved, changing the “front” volume. In a single production, this is really inconvenient, but when preparing a series (even a small one) - what's the problem?

Now about pluses. As you can imagine, the presence of a natural low-pass filter has led to a certain popularity of bandpass in the past, when passive filters were considered a natural way to separate frequency bands. A passive low-pass filter, tuned to a typical subwoofer frequency, involves the use of large and expensive coils. With the transition to dedicated bass amplifiers and active filters, this factor became irrelevant. However, given that most truly musical amplifiers in our industry are equipped with second-order filters, the presence of an additional (acoustic) low-pass filter will be very useful.

The ability to reproduce low bass is a good thing, but not for us. Let's say a subwoofer for a home theater in the WL can play bass from 50 Hz, in a design with FI - from 32, and in a PP design - from 25, and if you sacrifice the uniformity of the frequency response, you can reduce the frequency border to 20 Hz. However, in our industry, there seems to be no problem with low bass, the subwoofer in the WL plays (in theory) from 0 Hz. We have other problems with mid-bass flatness, as the transition from free field to compression occurs between 55 and 70 Hz (-3dB of boost). All subwoofers with FI give a rise starting from this frequency and downwards, a 3A tuned exactly to the transition frequency will give a straight-line response, but, of course, without any rise. With all other settings, the WL will either rise in the mid-bass region of 70 - 50 Hz, or, even worse, decline at the same frequencies.

So, a fourth-order bandpass (hereinafter, we will only talk about it, we will avoid unnecessary difficulties) can give rise exactly where it is needed, near the upper border of its working band, and maintain an attractive shape of the frequency response in cabin conditions. I think this alone is enough to take a closer look at it. Well, the last of the above pluses is also worth something.

So, let's start looking. We take some nameless speaker, we are not interested in its characteristics for the time being. So far, we are building characteristics in a free field, so it’s clearer. Let's see how the frequency response changes depending on the size of the "back" (that is, closed) volume.

Rice. 1. Change in characteristics depending on the size of the closed volume

Rice. 2. Change in characteristics depending on the size of the front volume

Rice. 3. Change in characteristics depending on the mass of air inside the port

Rice. 4. Change of characteristics depending on the bandwidth

As you can see, even with a volume change of more than three times (by 10 dB), the bandwidth changes insignificantly. However, as the volume decreases, the rise in the characteristic shifts to the lower limit of the passband. And we don't need it. Therefore, the benchmark will be simple, the first volume should correspond to the EP with the Butterworth quality factor or slightly lower, say, from 0.62 to 0.72 (green curve on the graph). To avoid bulky boxes, we must immediately focus on heads with a quality factor of at least 25% lower than this indicator, that is, no higher than 0.47 - 0.5.

Now notice that all curves pass through some point. This is the resonance frequency of the port and the front volume, we will call it the center frequency. In this case, it is 38 Hz, such a choice is typical for a home subwoofer, in our area the center frequency should be chosen much higher.

The upper frequency limit depends most of all on the value of the second (front) volume.

By reducing this volume, we extend the frequency range upwards while gaining a boost in response. The shape of the high-frequency part of the characteristic is due to the resonance of the phase inverter with a joint elasticity due to the stiffness of the suspension, the elasticity of the rear air and the elasticity of the air in the front volume. A 3 dB boost (orange curve) occurs when the top resonance frequency is an octave above the center frequency. The mass of air inside the port affects the lower frequency limit and at the same time the shape of the characteristic.

The characteristic in this area is due to the resonance of the combined air mass inside the port and diffuser with the joint elasticity of the suspension and rear volume. Luckily, we don't need a lot of mass, just move the bottom resonance 1/3 octave away from the center frequency (brown curve). To understand the nature of the bandbass, it will be useful to see how the shape of the characteristic will change if we keep the port setting, but at the same time change both the mass of air inside it and the volume of the front chamber.

The graphs are shown in an idealized form, which is obtained without taking into account leaks (as well as non-rigidity) of the case. If this is taken into account, the central part of the graphs will never reach the level of 0 dB. However, in the current theory, losses are not taken into account.

Now let's move on to practice. Let's choose two heads from test No. 2 for this year. Their parameters meet the Qts criterion<0,5. Как показало моделирование, чтобы избежать провала характеристики на суббасовых частотах, надо, чтобы частота резонанса головки в ЗЯ (заднем объёме) была не выше 50 Гц. Потому добавляем ещё один критерий: Fs <35 Гц. Вот что мы выбрали:

Head #1. Fs = 31.6 Hz; Vas = 29.3 L; Qts = 0.480.

Head #2. Fs = 33.4 Hz; Vas = 22.0 L; Qts = 0.454.

To calculate the PP of the fourth order, you can use many of the ready-made programs: not all of them give the expected results, but the old JBL Speakershop (aka Bass Box) in this case gives quite correct ones. If, as already mentioned, we discount the possible leaks of the hull. But for meaningful calculations, it is desirable to have some starting points. For example, for the first head, pre-calculate the volume of the IC in which the Butterworth (or slightly lower) quality factor is achieved. For Butterworth, we get 24.7 liters. If, after installing the head in such a box, we measure the impedance characteristic, then it will look something like in Fig. 5:

Rice. 5. Characteristic of the impedance of the head No. 1 in the IC

Now we need to determine the front volume. A good starting point would be 1/3 of the rear, in this case 8.2 liters. As a result of the simulation, the corrected value of the front volume is 8.06 liters, which is almost the same. During the calculation, we obtain a characteristic in the free field such as shown in Fig. 6. The graph shows the approximate position of the resonant frequency of the port.

Rice. 6. Subwoofer free field characteristic

However, we are much more interested in the performance of a subwoofer in a car interior. If the standard transfer function of AvtoZvuk is superimposed on the previous graph (it was published in its entirety in No. 8/2000), then we get the picture depicted in Fig. 7.

Rice. 7. Characteristics of the PP subwoofer in a typical cabin. Head No. 1, cutoff frequency 100 Hz

As you can see, the maximum amplitude spread over the entire operating range from infrasound to 95 Hz is less than 2 dB. A similar characteristic can be obtained with the help of the ZYA, but on the side of the bandpass there is also a constant acoustic gain of 3 dB, plus an effective slope of 18 dB / oct on top.

For completeness, see Fig. 8 impedance characteristic. The frequency of the port is 64.3 Hz, the lower resonance is tuned an octave lower, the upper resonance is about 2/3 octaves higher.

Rice. 8. Subwoofer PCB impedance characteristic. Head No. 1, cutoff frequency 100 Hz

What happens if we make a mistake with the volume of the front drawer during production? Say, 10% (Fig. 9)?

Rice. 9. Detuning the volume of the front drawer by ± 10%

Especially terrible - nothing. The upper frequency limit changes by 5%, but the shape of the frequency response does not change radically. But it is not recommended to make a big mistake in the realization of the air mass inside the port, the consequences are shown in Fig. 10.

Rice. 10. Port mass detuning by ±10%

A deviation of the air mass inside the port by 10% to each side (that is, a 5% change in the tuning frequency) results in a deviation in the frequency response of 1 dB in either direction.

With the head number 2, although not quite identical, but a similar set of characteristics is achieved. In this case, we set the first volume to a quality factor of 0.66, for this we need a box (part of the box) with a volume of 21 liters. The resonant frequency in such a ZA would be equal to 48.8 Hz. The front volume as a result of the simulation was chosen to be 7.3 liters. The calculated frequency response is shown in fig. eleven.

Rice. 11. Characteristics of the subwoofer software in a typical cabin. Head No. 2, cutoff frequency 100 Hz

The unevenness in the entire range is not more than 2 dB, the upper cut-off frequency is about 95 Hz. The steepness of the decline - the same 18 dB / oct. If we now turn to the impedance characteristic (Fig. 12a), it will not be difficult to see that the characteristic frequencies here are almost the same as in the case of head No. 1.

Rice. 12. Subwoofer PCB impedance characteristics. Head #2: a) cutoff frequency 100 Hz; b) cutoff frequency 80 Hz

If we need to work in a narrower bandwidth, then the settings will change in a predictable way (Fig. 12b). To get an upper frequency limit of 80 Hz instead of 100 Hz, we will need to lower the center frequency and the upper resonance frequency by about 10%. In this case, the frequency response takes the form as in Fig. thirteen.

Rice. 13. Characteristics of the subwoofer software in a typical cabin. Head No. 2, cutoff frequency 80 Hz

The unevenness has increased to 3 dB, although unlike FI, which tend to focus on the lower bass, the PP design has a decline around 30 Hz, where, in fact, the informative bass ends. True, in order to narrow the strip on top, the front volume had to be increased to almost 10 liters. Paradoxical as it may seem, but the bandpass design in our conditions works better in a wider band.

There is very little left to add. That the bandpass, for all its apparent "technocratic" nature, radiates like a closed box, and therefore its transient characteristics are more interesting than those of FI. For the same reason, his (correctly tuned) bass turns out to be more collected, which is important for SQ installations. Finally, in terms of full volume, the bandpass loses not so much to the phase, we can say that the amount of loss is equal to the amount of the front volume. This is the price for uniform acoustic amplification, in other words - for increased efficiency.

From the history of bandpass

In order not to give the impression that the bandpasses came up with “just now”, two illustrations with dates. The first is a US patent issued in the name of a man with a noble French surname d'Alton. He came up with the bandpass as a narrow-band emitter, counting from a multitude of such, tuned to different frequencies, to assemble broadband speaker systems of great efficiency in the manner of a church organ.

The idea is wild and, as history has shown, of little use, but the device, and, as far as one can judge from the lonely schedule, the nobleman understood the characteristics, in principle, correctly.

Twenty years later, when the speaker (that is, the direct-radiation electrodynamic loudspeaker) finally supplanted other means of sound emission, another patent appeared. It already explicitly states that this is a way to extend the bandwidth down with a separate, relatively narrow-band acoustic unit. That is exactly what we today call the word "subwoofer".

Moreover, Henry Lang's explanations already feature sound pressure curves very similar to those discussed in today's publication. “The process started” from that moment.

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The subwoofer is an integral part of any modern system, designed for watching films rich in special effects or listening to music of various directions. This acoustic element is designed exclusively to reproduce low frequencies, the abundance of which gives the music significance and the effect of high power. It is powerful basses that sometimes form the initial opinion about the quality and advancement of acoustics in general. This is understandable, because the bottom of the sound range is just the most demanding on the speakers, the materials and components used. In this material, we will not go into complex technical details, but will try to highlight only the main points that are important for the average buyer who went to the store for a subwoofer.

If you decide to purchase a subwoofer...

First of all, you should evaluate your financial capabilities and the topology of the proposed listening room. It is easy to guess that one of the decisive factors is the cost of a hypothetical acquisition. Any acoustic system works according to the laws of simple physics, which state that the size of the emitter must be comparable to the wavelength. And since for low frequencies it is measured in tens of meters, then the dimensions of the speaker should be measured at least in tens of centimeters. There are a huge number of different technical solutions and tricks, however, getting really high-quality bass from a speaker smaller than 5...6" is simply unrealistic, ideally it should be close to 10...12". Therefore, when purchasing a tiny multimedia subwoofer, it is worthwhile to understand that the resulting bass is unlikely to reach the results of an ordinary average speaker.

Based on this consideration, it is worth once again soberly assessing your budget and the level of available acoustics. If we are talking about "under $100" class computer systems, be it, for example, the classic 2.1 version, then their subwoofers are a pitiful imitation of full-size systems. After all, even the most basic options cost at least $70, and the dimensions of the cases are measured in tens of centimeters and can reach up to half a meter. Therefore, having gathered in the store, ask yourself three questions. Are you really willing to spend money on a quality bass subwoofer? For a cheap option can disappoint from the first minutes. Does your speaker system really need a subwoofer? After all, a subwoofer will not help a lot for budget speakers, but for expensive solutions, a subwoofer may not be required. And is there the necessary space and facilities for installation.

Active or passive?

So, suppose that the decision is made, it remains to decide on the main parameters. Like all acoustic systems, subwoofers are active and passive, i.e. with or without built-in amplifier. It is classically believed that real acoustics should be passive. This improves the parameters of the speakers themselves, and simply allows you to change amplifiers, finding the sound you like best. There are passive subwoofers, but there are still more active models. The fact is that the speakers, at least, are used in pairs when the subwoofers are monochannel. To put it simply, a subwoofer needs an amplifier with one channel, and with non-standard adjustments. Naturally, there are such, but the easiest way is to purchase just the active option. Passive subwoofers are popular only among motorists, which is associated with some subtleties of connection and huge power. Also, we do not take into account various audiophile habits when tube amplifiers or other extraordinary solutions are used for subwoofers. If we are talking about a computer system or a moderately priced home theater system, then we recommend active solutions.

Power

We have more than once that the power figures indicated by the manufacturer poorly characterize the real parameters of the system, because. there are many standards for measuring this parameter, which gives rise to numerous "additives". You can start from numbers, but you need to do this with a certain amendment. Roughly speaking, it is necessary to strive for the declared power of the subwoofer to be close to the power of the satellites used. This is how the necessary headroom and balance in sound pressures are achieved. For example, consider the simplest case. Let's say you have microlab SOLO-6 speakers with a total power of 100 W, and their bass, according to the user, is rather weak. In this case, a subwoofer with a power of at least 80 ... 100 W and a speaker 8 ... 10 in size can radically improve the situation. Buying a subwoofer for such speakers with a five-six-inch speaker is simply pointless.

Types of subwoofers, their main advantages and disadvantages

With a more specific search, any user will immediately realize that there are at least several different subwoofer designs. Of course, I want to know about the advantages and disadvantages. To begin with, let's look at the simplest constructive option - a closed box. With this design, the low-frequency head is simply placed in a case isolated from the external volume.

For all its simplicity, this acoustic design is quite nice, because the column is slightly influenced by the room, and the sound is confident and biting. However, there is one significant drawback - the efficiency of such AO is extremely low. In other words, to get high sound pressure, the manufacturer needs to initially use a high power speaker and an appropriate amplifier. For reasons of simple economy, this is extremely unprofitable, because. too many materials are required. If this is acceptable for real Hi-Fi, then for multimedia this option is obviously losing. The user simply does not want to pay money for a subwoofer / speakers that play well, but quietly. That is why there are very few closed boxes among computer systems, and in other areas they are not as popular as even the simplest phase inverters. It turns out that to increase the sound pressure with the same parameters of the head and amplifier, it is enough to equip the closed case with a pipe through which the internal volume will communicate with the external space. The phase inverter helps to change the phase of the oscillations from the rear wall of the diffuser and adds them to the oscillations from the front. As a result, the power increases. The disadvantages of this option is the likelihood of jet noise and peaks in the frequency response. The latter are possible due to errors in calculations or poor influence of the room. However, the power indicators greatly cover the appearance of possible shortcomings, so most of all subwoofers on the modern market are just phase inverters.

Often, an even more efficient design is practiced, called bandpasses (bandpass resonators). The speaker is placed inside the case and communicates with the external environment through one or more phase inverters. The advantage of this option can be considered that it allows you to "pull out" the bass even from the smallest speaker. Sometimes multimedia subs are built using 3 ... 5 "heads, and at the same time they at the very least bass. However, such an acoustic design is very sensitive not only to the setting and spread of the parameters of the heads themselves, but also to the room. Therefore, inexpensive bandpasses play powerfully, but there is no beauty in their sound, and a cheap bandpass is most likely not the best option in terms of quality.The situation is better with more expensive solutions.

Placement in the room and basic adjustments

It should be noted right away that there are no clear rules for installing subwoofers in rooms, however, like all acoustic systems, they are subject to the influence of the listening room. It is best to choose a place empirically. As a rule, the subwoofer is installed on the floor between the front satellites or near one of them. You can move the low-frequency unit closer to one of the speakers in the corner of the room. Such liberties are due to the fact that low-frequency sound is not localized by the human ear. Naturally, you should not install close to the walls, especially if the phase inverter port is placed on the rear or side panel. To achieve the best option, it is worth conducting several test listenings, choosing the most suitable place. It will be individual even for rooms of the same size, because. a lot depends on the decoration of the walls, the location of the furniture, etc.

More precise adjustment can be made with the help of several convenient adjustments, which are provided in the vast majority of cases. The first is the volume control. Everything here is very individual, because. someone likes a moderate bass, while the other, on the contrary, prefers the prevalence of low frequencies. In any case, the subwoofer-satellite volume balance is the most necessary adjustment, which is always present. In second place is the cutoff frequency, which, as a rule, regulates the upper limit. It helps to match the frequency response of the subwoofer and the main speakers. The boundaries must be chosen so that there is no significant overlap, but also no dip is formed. All this can be done based on subjective feelings. Finally, any more or less high-quality subwoofer has the ability to adjust the phase or, as they say, delays. This function is provided for position compensation so that the sound at the listening point from all speakers arrives at the same time.

Summing up

In conclusion, we can only describe the approximate actions of a user who decides to purchase a subwoofer, and give the briefest recommendations. To begin with, it is worth deciding on the price, because. ultra-cheap options tend to bring nothing but disappointment. Still, buying a separate subwoofer implies a desire to get high-quality bass, and you have to pay for it. Secondly, it is worth deciding on the type of acoustic design and power, paying attention to the dimensions of the case and the possibilities of the room. Finally, thirdly, it is worth conducting a test listening, choosing the optimal location, and adjusting the sub in conjunction with the speakers used.

When choosing, it is worth remembering only one unshakable rule, the sound is very individual, and each person has his own unique preferences. Reading reviews and studying technical characteristics will help weed out frankly unsuccessful options, but you will have to listen to the rest, because. only listening gives a guarantee that a hypothetical purchase will be liked in the future.

On this page, we will briefly go over the elements that make up any woofer and midrange speaker. This will help you better understand the subwoofer and more fully understand the sound reproduction process.

So what is a subwoofer or subwoofer. A subwoofer is a device that converts the frequency of the signal into air vibrations, which we perceive as sound.

The principle of operation is as follows - the signal from the amplifier is transmitted by wire to a coil, which, when interacting with a magnet, moves and moves the speaker cone, which creates sound waves (air vibrations).

Now enough definitions, let's take a look at the pictures.

Components

Below are the main elements that make up the subwoofer.

suspension— fastens the diffuser to the basket. Together with the length of the coil winding, it affects the amount of speaker travel, and elasticity and strength depend on the material.

mounting ring- acts as a sealant, in some models it can attach the suspension to the basket.

Lead out- a modern solution is to lead the wires from the coil along the centering washer, which eliminates the possibility of damage and extraneous sounds during operation.

Terminal- speaker wires from the amplifier are connected to the terminal block, in some models it may be absent, offering the owner a direct connection, or a connection through the housing terminal.

voice coil- located in the gap between core and top flange where the magnetic field is formed. coil is a cylinder sleeve), on which a thin copper wire is wound ( coil winding). Sleeve connected to diffuser, due to which it is set in motion.

Basket is the body of the speaker and the frame for all elements.

dust cap- prevents dust from entering the gap of the voice coil.

Diffuser- the area that creates vibrations in the air, which we hear as sound.

Centering washer- Centers and holds the coil in the gap.

Magnetic system. Magnet It is made from special alloys or magnetic ceramics - pressed and "sintered" powders in a special way. The power of the speaker depends on the mass and material of the magnet.

Magnet located around core and fixed between top and lower flanges. All this together makes up the subwoofer's magnetic system.

Ventilation holes and air outlet channel used to remove heat and protect the coil from overheating. Cooling is passive and active, both options are used in speakers. With passive cooling, heat is dissipated due to the heat transfer of materials, and with active cooling, hot air is removed due to the movement of the diffuser, respectively, when accelerating or increasing the range of motion, the cooling intensity also increases.

Conclusion

These were the main elements that make up the subwoofer device; low-frequency and most mid-range speakers have this principle. High-frequency ones are built somewhat differently.

The totality, materials and interactions of all these elements determine the characteristics of the subwoofer, and of course the character of the sound and the quality of the speaker.

Video about what a subwoofer consists of

I hope after this material you figured out what the subwoofer consists of and how it works.

Choosing the right subwoofer is quite important when creating a personal sound system for your car. Today, different manufacturers offer many models, but in this article we will talk about how an active and passive subwoofer differ, what are their disadvantages and advantages.

So, what is the difference between an active subwoofer and a passive one?

Unfortunately, not all car owners can give a clear answer to this question.

What is a passive subwoofer?

A passive subwoofer is one or more woofers that are housed in a wood, plywood, or MDF cabinet. In order for it to reproduce sounds, an external amplifier is needed, and a sound separation filter, which leaves only low frequencies from the signal.

What is an active subwoofer?

An active subwoofer is a speaker system that has a built-in amplifier, a crossover filter and, of course, one or more speakers. This system is somewhat easier to connect, and by popular belief sounds somewhat better than a passive subwoofer. But as practice shows, it all depends on the overall setting of the speaker system.

Active vs Passive Subwoofer: What's the Difference?

In order to understand which subwoofer is better, passive or active, let's compare the main indicators that, one way or another, all car owners pay attention to:

• Cost - active subwoofers are more expensive, which is not surprising because they have a lot more expensive electronics;
• Ease of Installation - Since passive subwoofers require an external amplifier, frequency filter, etc., they are somewhat more difficult to install. In addition, active systems already have a built-in amplifier, and this can save a lot of space;
• Sound quality - It would seem obvious that an active subwoofer should sound better, in fact, everything is somewhat more complicated. After all, in order for the speaker system to sound good, it must be properly configured. And as practice shows, a well-tuned passive subwoofer can sound better than an active one;
• Ease of setup - on the one hand, active subwoofers have more tuning options, but if you have a good external amplifier, this advantage comes to naught.

Advantages and disadvantages of passive subwoofers

As already mentioned, a passive subwoofer is, in fact, just a speaker equipped with a special speaker that emphasizes low frequencies. Accordingly, such an element of the acoustic system will cost relatively inexpensively.

But this is far from the only advantage of passive subwoofers. With their help, you can assemble a system in which all components will satisfy your ideas about the right sound as much as possible. After all, in order to get the optimal sound, you need to assemble a set of a suitable amplifier, the necessary frequency filters, and a set of speakers in suitable cases.

Also quite important point is that, unlike active, passive subwoofers use different types of cases, namely standard boxes, phase inverters, bandpass. In active systems, the ability to use different types of cases is hampered by the need to place additional electronics in them.

Advantages and disadvantages of active subwoofers

Of course, the main advantage of active type subwoofers is that a speaker, an amplifier and a filter are combined in one housing. This makes it as easy as possible to connect them to car radios, and provides a certain sound quality with a minimum of settings.

Unfortunately, this is their main drawback. Due to the need to fit both the speaker and the electronics in the same enclosure, there are some compromises to be made. In particular, this applies to underpowered amplifiers, which naturally affects the power, sound pressure and responsiveness of the system.

Of course, there are models in which all components allow you to get the highest quality sound. But, unfortunately, their cost is quite high.

In order to reduce the cost of active subwoofers, manufacturers quite often try to reduce the cost of components as much as possible, which makes the sound of most of them somewhat rough. It also affects their reliability.

Separately, it is worth mentioning the power of active type subwoofers. The fact is that in order to ensure sales, manufacturers often attract their potential buyers with a combination of small dimensions and high power. But in fact, really good sound with a powerful amplifier is impossible without a speaker of the appropriate size, namely 10, 12 and more inches.

What is the best choice for a car owner?

The differences between an active subwoofer and a passive one are quite obvious, and based on them, car owners make their choice in favor of one or another option.

People who want to improve their installed speaker system a bit tend to purchase inexpensive and compact models of active subwoofers. They are quite easy to install, but you should understand that in a compact case it will not be possible to place a really powerful high-end amplifier. Accordingly, such a subwoofer will slightly improve the sound, but will not give a really powerful and punchy bass.

If the car owner is disappointed in the sound of an active subwoofer, and the return period has expired, then the question naturally arises - “is it possible to make a passive subwoofer out of an active one?”. Of course, in practice this is possible, but it is worth understanding one simple point. In most active systems, the speaker is somewhat inferior compared to passive subwoofers.

Also, before choosing a subwoofer, it makes sense to check if your radio has a built-in amplifier. Today, many cars are initially equipped not only with a car radio, but also with amplifying equipment. In this case, there is not much point in purchasing an active subwoofer, unless you want to get a very powerful sound, at a power of 250 watts.

A rather important point is that active subwoofers have factory settings that are designed for the most popular styles, in particular, various dance music, etc. Therefore, if you consider yourself a gourmet of sound, then they may not be enough.

Let's summarize. In order to clearly understand which subwoofer to choose - active or passive, you need to clearly articulate your requirements for the car's speaker system. In particular, the following parameters must be defined:

• The presence in the radio of a built-in amplifier of the required power;
• Free space in the car to accommodate the subwoofer;
• Planned budget;
• Free time that you are willing to spend on setting up the speaker system;
• Requirements for the sound of the car's speaker system (want to add some bass, or plan to enter a car audio competition).

As you can see, choosing which type of subwoofer suits you best is not as easy as it seems. After all, in addition to the above factors that affect the choice of model, a lot depends on musical preferences, etc.