Difference between passive and active subwoofer. Distinctive features of an active and passive subwoofer

Speaker systems that are designed to reproduce audio frequencies ranging from 20 to 120 Hz are called subwoofers. Principle of operation this device is to convert electrical signals into acoustic. When potential consumers ask what a subwoofer is, the above explanation is sometimes not enough. For this reason, specialists have to describe in more detail specifications presented device.

Device types:

Active;
Passive.

In fact, it is not so difficult to explain what an active subwoofer is, because it is a model that includes a power amplifier in its design, as well as an active crossover. Such devices are capable of receiving and converting, as a consequence, signals related to the line level. Active subwoofers can easily be connected between the signal source itself, as well as full-range speakers. This type connection is called end-to-end by experts. Corresponding subwoofers quite often have additional features in order to adapt to specific conditions of use. In this situation, we can talk about the steepness of the cut, adjusting the frequency response, the position of the cut points of the crossover itself, etc.

Quite common autonomous active subwoofers are characterized by the fact that they combine in one design not only a subwoofer with a crossover filter, but also a power amplifier of very high quality in its design. This type of subwoofer is endowed with line inputs, which serve to connect to a very important preamplifier from a technical point of view. Line outputs are also included in the design. They emit a signal that goes to the power amplifier. For ease of use, stand-alone models also include a special regulator in their design, which is designed to control the subwoofer signal. The crossover frequency is also overwhelmingly adjustable on the device.

It is absolutely logical that motorists are wondering what a passive subwoofer is, which is also very popular among buyers. It should be understood that such models consist not only of the case, but also of the speaker. This allows them to connect to a power amplifier without any problems. To put it as simply as possible, a passive subwoofer is one or even several woofers that were placed in the case. These heads must be connected to an external amplifier.

There are several options at once, thanks to which a passive type of subwoofer is connected. One of the most well-known schemes involves the signal from the side of the stereo amplifier. In the future, those same signals are sent not only to the subwoofer, but also to the most basic speakers. In fairness, it should be noted that this connection option is far from the most desirable. The fact is that this circuit provides for the output signal from the power amplifier to the input of the subwoofer itself. This circumstance leads to the fact that the crossover filter is engaged in the removal of low frequencies from the signal. The main speakers subsequently receive an already filtered signal.

Types of acoustic design

by the most simple view acoustic design of the subwoofer is a traditional closed box, but this option is definitely not the only one. A fairly well-known type is the phase inverter. On one of the walls of the subwoofer in this case contains a tunnel with a well-defined diameter and length. An almost identical option is a passive radiator. However, this type of acoustic design contains an additional speaker instead of a tunnel. True, it is not equipped with a magnetic system and a voice coil. Another very interesting option is the labyrinth. The back wall of such a subwoofer is designed to work on a zigzag sound guide.

A closed box is a type of construction that does not provide for the presence of additional emitters. The box is completely sealed, and on one of its walls there is a subwoofer. Depending on its design, the quality of the final sound may vary.

Bandpass. This type of design is a bass-reflex box. In the middle of this design, a special wall is installed that separates the chambers, which differ in different volumes. As for the speaker, it is located directly on the partition between the cameras. It should immediately be noted that such a design is characterized by a fairly high efficiency of its work. As for the name Bandpass, its origin is easy to explain. The fact is that such a case without problems can significantly limit the frequency response that a subwoofer has.

Distinctive features of car subwoofers

Knowing thoroughly what an active and passive subwoofer is, it becomes clear that similar devices can be installed not only in vehicles, but also in the house. However, the difference lies in the installation process. Home models are very easy to install, but in the case of automotive counterparts, certain requirements must be met. It is no coincidence that drivers are actively interested in what a car subwoofer is and its main technical properties. These models are small in size, so they can be easily placed in the trunk.

Main problems

Before you learn about what an active car subwoofer is, you need to consider certain theoretical problems that may subsequently arise. First of all, it should be noted the need to use additional electronics. Initially, the bass sound quality may also be quite low. Of course, it is also important to know what a passive car subwoofer is, but the possible disadvantages should by no means be ignored. For example, not in all situations the sound of the presented device may coincide with the most basic speakers. These and other purely theoretical shortcomings are best known in advance and minimize the likelihood of occurrence during operation.

A fairly common problem is also the situation in which subwoofers are forced to reproduce quite deep bass in the course of their work. Due to high-quality controllability, this goal is still achieved, but the level of sensitivity of the device increases. This situation results in most subwoofers sounding somewhat slow or exaggerated. It is not uncommon to lose important details.

You should also not forget that subwoofers in certain situations are able to fill the vehicle with low-frequency energy. As a result, many resonant phenomena occur inside the machine. In order to avoid such consequences, it is necessary to pay special attention to the correct placement of the subwoofer inside the car. If you miss this fact, then there will be a high probability that the so-called "musical results" will be at a far from the highest level. If you install two subwoofers at the same time, you can somewhat mitigate the problem associated with excitation of frequencies in the car interior.

Causes of Subwoofer Hearing and Not Bass

The highest quality subwoofers are characterized by the absence of cabinet vibration. However, it is not uncommon for the case walls to emit sound as well. Vibration may also be encountered by other elements and panels. As a result, overtones become even more high-frequency. It happens that the problem arises trivially due to the fact that the filter settings of the amplifier were made with some errors.

Among other things, unwanted overtones may well be a logical consequence of air turbulence. Experts clearly know that at fairly low frequencies, the cone stroke is in most cases very significant. When exposed high temperatures it can even reach several centimeters. It is clear that in such a situation, the movement of air will be very significant, and this already leads to its turbulence.

The subwoofer manufacturer must have a positive reputation and good reviews. Otherwise, consumers run the risk of purchasing a subwoofer, the case of which is characterized by poor assembly. That is why before buying a subwoofer it is necessary to study it very carefully. Without exception, all panels of the device must be fitted in such a way that even the smallest gaps are completely absent. As you know, the smallest hole will automatically have a negative impact on the final sound.

A subwoofer is a speaker system that reproduces low-frequency sounds. Approximate range of frequencies converted by the device varies from 20 to 160 Hz. A person hardly perceives low frequencies, which is why he feels more outgoing vibration. However, sound waves can create the necessary atmosphere when listening to music or watching blockbusters, so the device is often included in the speaker system.

There are two types of subwoofers in relation to the power amplifier:

passive;
active.

Passive and active subwoofers

The separation is due to an amplifier, which is either built into the device or not, which requires its additional connection.

Passive subwoofers

The passive subwoofer is quite simple in design. It consists of a body and one or more low-frequency heads. They are later connected to an external amplifier. This type of device also differs in connection type. When transferring sound signal both the subwoofer and the other speakers experience severe sound distortion, so direct connection Not recommended. In order to achieve the purity of the transmitted sounds when listening to music, you should connect a passive subwoofer through a crossover filter, since it separates the bass from the higher frequencies.

Active subwoofers

An active subwoofer is a more advanced device, since an amplifier and a crossover filter are already built into it. This technique can be connected directly to the sound source, so it does not cause difficulties during the installation process. The active subwoofer has built-in functions for adjusting the level and frequency of the signal, the rear panel is equipped with line-type input and output connectors. A high-quality device allows you to clearly reproduce sounds from a wide range of low frequencies, which is important for good speaker system.

The difference between the two types of subwoofers

Depending on the purpose for which the device is purchased, it is better to give preference to one or another type. The standard active subwoofer settings are good for heavy or rhythmic music. The device transmits low frequencies better and allows you to adjust their severity. A passive subwoofer can also achieve a similar effect, but this requires expensive equipment connected to a powerful system.

Active subwoofers are already equipped with an amplifier, so there can be no problems with power differences. A passive subwoofer needs an external amplifier, since often the sound source and the speaker system have different capacities. If you connect them directly, the sound waves will be distorted, resulting in noise or the sound will be quiet even at maximum volume.

A passive subwoofer, when properly tuned, is capable of delivering cleaner sound that will outperform an active subwoofer. True, to achieve such a result, you will have to spend a lot of time and effort. In addition, not every layman understands these subtleties so deeply. Thus, for an ordinary listener, an active subwoofer will be much more preferable, and true connoisseurs of high-quality sound often acquire a passive one.

Why does a passive subwoofer sound cleaner?

As already mentioned, a passive subwoofer with correct settings capable of delivering a thicker and more voluminous sound. This is due to a number of parameters:

no overheating of the air inside the device;
the ability to connect additional filters;
external amplifiers have a large number of parameters for tuning;
the power and depth of the sound is enhanced by the fact that there are no unnecessary obstacles in the body.

In addition, when comparing active and passive subwoofers with similar parameters of converted sound waves, the latter will cost less, since they are not overloaded with additional devices. True, you will have to buy an additional amplifier, which will significantly increase the final costs.

How to connect an active subwoofer?

There are three ways to connect a powered subwoofer to a sound source. The diagram shows the most common input and output options for speaker system devices.

The subwoofer has two inputs. high level, so you will need a long and thick speaker cable to connect the device. When connecting, RCA cables or, in other words, "tulips" are used. One end is connected to the subwoofer, the other end is connected to the input on the back of the receiver labeled "Subwoofer". If the panel has two or four RCA connectors, then the white connector is used.

You can also use the outputs to connect speakers. In this case, both the subwoofer and the system will work in parallel in the low frequency range. It is allowed to connect active subwoofers to the amplifier, but this will only increase the load on the device, causing the sound quality to suffer.

How to connect a passive subwoofer?

If the subwoofer has two terminals, the device is connected through an amplifier to the Pre Out Subwoofer output. The connection diagram can be represented by the following chain: Passive subwoofer - Speaker cable - Amplifier - RCA cable - Receiver. In this case, it is necessary to set the settings on the receiver that limit the frequency of the reproduced frequencies.

Often, passive subwoofers are connected in parallel with the front speakers. For this:

three terminals on the back of the subwoofer are the pluses of the front speakers and a common minus;
the four terminals on the back of the subwoofer are the pros and cons of the front speakers.

To connect passive subwoofer it is recommended to use speaker cables with a thickness of 2.5 to 4 mm to the amplifier. During the connection process, the polarity of the plugs and channels must be observed. When using the device in home theater subwoofer outputs are connected to satellites.

Connecting a subwoofer in a car

Since car space is limited, most vehicle owners prefer active subwoofers. This is because the passive connection requires installation additional device- amplifier. To install the speaker system, you will need to perform a number of actions:

connect the linear outputs of the radio to the inputs of the subwoofer using the "tulip". If there are no such outputs, the connection is made to HI INPUT;
the subwoofer is powered by a positive cable from the battery to the twelve-volt subwoofer terminal and a negative cable to the GND terminal. The fuse must be installed 20 cm from the battery;
the subwoofer is connected to the radio via the REM control wire. It is carried out from the radio to the terminal on the subwoofer, it is better to take a thinner cable.

Which device to choose?

If you want to purchase a subwoofer, you need to decide which one is more suitable, taking into account the goals of the user. Some people need bass in the car, others need bass to listen to their favorite music, others prefer surround and multifaceted sound when watching movies. For regular user an active subwoofer is more suitable, as it does not require complex settings and parameter matching different devices when connected.

Few users prefer passive devices, as their configuration requires special knowledge. If you have the right amplifier and the ability to adjust the parameters to your needs, you can give preference to this type, which can give a more dense sound.

Which sub to choose

As you know, the debate about which subwoofer is better active or passive still does not fade away. Some dispute the benefits of an active subwoofer, while others vehemently defend this speaker, arguing that it is much easier to install and connect.
We learn from our article which is better active or passive subwoofer?

What is the difference between these speakers

Subwoofers tend to reproduce bass. But active and passive speakers are known. Do we know why they are called that?

passive sub

This:

The ultimate simplicity of design distinguishes a passive subwoofer.
Such speakers consist of a case and one or more low-frequency heads connected to an external amplifier (see).

Note. Passive subs can have two types of connections. The first method involves transmitting the stereo amplifier signal not only to the sub, but also to the rest of the speakers. The second method involves connecting with a crossover filter that qualitatively separates the bass and signal.

active sub

So:

The composition of the active subwoofer includes a crossover filter and a power amplifier. This is a very mobile combination of several devices that meet separately.

active sub has line inputs and outputs, as well as a special function for adjusting signal level and crossover frequency.
A high-quality active subwoofer can significantly expand dynamic range, which naturally will have a beneficial effect on the quality of music.

Comparison

So:

Active sub first better fit for dance and rhythmic music. This speaker with all its default settings has more flexible options and adjustments.
Secondly, active speakers, having their own amplifiers, are no match for passive ones. If they are of high quality, they are much better than passive ones, because they do not have their own amplifier.

Note. It is not uncommon to tune a passive subwoofer so that that speaker sounds even better than an active speaker, but this is considered to be a very delicate and painstaking process.

Thirdly, an active subwoofer is easier to install (see), because it is much faster and easier to set up.

Difference

To be more precise, the difference between these two speakers will look like this:

An active subwoofer is better than a passive one, because it has a built-in amplifier. And to connect a passive subwoofer, you will need to look for external sound amplifiers.
It is much easier and faster to set up speakers with an active subwoofer than with a passive one.

A speaker with a passive subwoofer, if tuned accurately and efficiently, sparing no time and effort, will give more surround sound than a system with an active subwoofer.

Note. It can also be said that the active subwoofer is chosen by beginners and those who are not so interested in the depth of sound. On the contrary, those who seek not only loud noise or ease of installation, passive subwoofers will be happy.

Important information

So:

It will be interesting to know that an active subwoofer is the same passive one, but it is equipped with an additional bass amplifier.
Today, active subwoofers are more popular than passive ones, and this determines their cost. It is the popularity of the active subwoofer that makes many people think that it is a priori better than the passive one.

If you have a separate amplifier, then there is nothing better than purchasing a passive subwoofer.
In no case should you go on about bright advertising. Today, every manufacturer can shamelessly lie, if only his products were purchased from him.
It is recommended not to believe the words, but to refer to the reputation of the company and judge, as they say by deeds. By following exactly this advice, you can find exactly the subwoofer that suits you.

How to choose the right subwoofer for your speaker system

So, the difference between an active and passive subwoofer is known. Now we will learn how to choose the right subwoofer for your speaker system.

Analysis of the existing acoustic system

First of all, you need to analyze what is available. If simple speakers and an amplifier are available, then it does not make sense to buy an expensive and powerful subwoofer, since it will not sound good anyway.

Note. According to professionals, before buying a subwoofer, you need to set up the speakers in such a way that it gives out bass of relatively good quality.
Such a bass, of course, is not the main one and is also called "acoustic". By installing a subwoofer, you can get high-quality lower bass, which, in addition to the sounds of the speakers, will give excellent sound.
Allegedly, what is expensive and good sub capable of giving both lower and upper bass, is not justified by practice.

Sub choice

The second stage involves deciding whether an active or passive sub will be selected. As mentioned above, the first option is easy to install in a car, because it will just need to be connected to the speakers. But, oddly enough, an active sub has its drawbacks.
Disadvantages of an active sub:

Such an active speaker gives a worse sound than a thoroughly tuned passive one.
Often, in the manufacture of active subs, cheap components are used that make the sound rough.
As a rule, an active subwoofer is cheaper than a passive one, precisely because of the low-quality materials used in its production.

Probably, any fan of quality music would like to enjoy their favorite compositions on good and powerful sound equipment. Well, for this, speaker systems with powerful subwoofers appeared. As a rule, the main dilemma when buying such a system is whether to choose a subwoofer - active or passive.

Definition of passive and active subwoofers

Passive subwoofer is extremely simple in design - it consists of a cabinet and one or more woofers, which are then connected to an external amplifier. There are also two types of passive subwoofer connections. The first type is the least preferred due to the presence of sound distortion and lower quality of its transmission - in this case, the stereo amplifier signal is fed not only to the subwoofer, but also to the rest of the speakers. Connecting with an electronic crossover filter is much more reasonable because it effectively separates the bass from the signal going to the other speakers.
Part active subwoofer includes both a crossover filter and a power amplifier. Thus, an active subwoofer is a mobile combination of several devices that can be found separately. The active subwoofer has line inputs and outputs, as well as a function to adjust the signal level and crossover frequency. As a rule, a good active subwoofer significantly expands the dynamic range of the speaker system, which, of course, will have a beneficial effect on the quality of the music.

Comparison of passive and active subwoofers

Firstly, an active subwoofer with its standard settings is on average better suited for heavy or dance and rhythmic music, since it transmits bass frequencies better and has more flexible settings and adjustments (except when using an expensive speaker system and a very high-quality passive subwoofer ). Secondly, active subwoofers have their own amplifiers, while passive subwoofers need external amplifiers. However, a system with a passive subwoofer can be set up to sound better system with an active subwoofer, but this is a very painstaking and delicate process. In this regard, an active subwoofer is much more convenient, because it is much faster and easier to set up, but many connoisseurs of good sound prefer to spare no time and effort to set up passive systems.

TheDifference.ru determined that the difference between a passive and an active subwoofer is as follows:

The active subwoofer has a built-in amplifier. A passive subwoofer needs to be connected to external audio amplifiers.
Setting up a speaker system with an active subwoofer is much faster and easier.
When tuned as accurately and as accurately as possible, a system with a passive subwoofer will usually produce a more spacious and dense sound than a system with an active subwoofer.

The basic acoustic system of the radio often does not suit the owner of the car with the sound, the presence of interference, and the fuzziness of the reproduced frequencies. Music lovers certainly want to equip their car with a subwoofer - a device that allows you to hear the full range of bass in any composition. Find and buy desired device today, it is not the slightest difficulty, since there are many options. Therefore, it is important to know how an active subwoofer differs from a passive one, taking into account not only its cost, but also the features of sound and operation.

The design of any subwoofer is one or more low-frequency speakers placed in a single housing. The difference between an active subwoofer and a passive one is as follows:

The passive option is actually a set of speakers in the case. In order for low-frequency sounds to be reproduced with the required clarity, additional equipment is needed - an amplifier and a filter that eliminates interference from the sound and highlights the bass;
Active. The design already provides for a built-in amplifier and filter in the subwoofer cabinet.

It is definitely impossible to say which subwoofer is better - active or passive. First you need to consider all the advantages and disadvantages of each system.

Pros and cons of active and passive subwoofer

To evaluate what is better active or passive subwoofer should be based on vital criteria. This:

Sound quality. It would seem that the active version has all the advantages - the built-in amplifier and filter should independently "lay out" the frequencies and produce a finished high-quality sounding product at the output. However, car music lovers, who have encountered a problem in practice, unanimously claim that a clear sound will depend on the system settings;
Dimensions. How to understand whether an active or passive subwoofer should be purchased for a particular car model? Indeed, the question is urgent, since the space of the trunk (the traditional place to install a subwoofer) or the cabin is often limited. It is worth remembering that the passive design requires additional equipment, respectively, they are more often placed in cars with large interiors and trunks, such as crossovers. If the car cannot boast of spaciousness, then the subwoofer is placed in the back of the cabin or in the armrests. In the latter case, preference is given to active options;
Price. It is higher for an active subwoofer due to the expensive electronics responsible for the operation of the total system - speakers, amplifier, filter. And, of course, compactness is also a priority. A passive subwoofer by itself costs less, but requires the purchase of an amplifier, frequency filters, etc. On the other hand, it makes up for it in sound quality;
Possibility of independent connection. Installing a subwoofer of any type is not difficult if you approach the work responsibly. With the passive option, you will have to spend a little more time. The complete set with the device always comes with a detailed diagram and. It is important to observe safety measures - use high-quality components, de-energize the car before work, etc.;
Possibility of customization. True music lovers prefer to manually complete the speaker system with devices that, in their opinion, give the best quality sound. Therefore, they are much more likely to choose passive subwoofers. Of course, if you do not want to waste your time, then an active subwoofer would be a better option.

So, active or passive subwoofer? Which to choose? The answer is that everything is individual. First of all, when choosing, you need to accurately determine your expectations from the modernization of the audio system, as well as the financial capabilities and features of your car. Based on this, it will be possible to choose the appropriate option. The main thing to understand is that both an active and a passive subwoofer cannot be of high quality, at a low cost. Therefore, you need to either buy the most expensive option, or make a reasonable compromise.

Of course, before buying it makes sense to familiarize yourself with the most popular models. This can be done thanks to our rating of active and passive subwoofers.

Manual setting of an active or passive subwoofer

The factory settings of active and passive subwoofers do not always allow you to get quality sound. To achieve the perfect sound, the user can try to adjust the device on their own. For instance:

Frequency tuning. It is made taking into account the main characteristics of the device. They are listed in the user manual. Naturally, a selection better sound happens by ear
Crossover adjustment. This device sets the required frequency for each speaker, which makes the sound of the system smooth and harmonious. The default crossover setting is 80 Hz. If the sound is booming, the value is lowered. For clarity of sound, increase accordingly;
Phase switch setting. This device is designed to compensate for the difference between the remaining satellites in the system. It is recommended to tune it by playing records with male voices - bass, tenor and alto. That is, with different range sounds;
Elimination of acoustic distortions. They may also have good models active or passive subwoofers. What can cause distortion? For example, cable dispersion is often the cause of acoustic hum. Adjusting the volume will help fix this problem. But most often, the reason is the poor quality of the wire. In this case, it would be best to change the connection cables to RCA wires with a shielding function.

If knowledge about the subwoofer is not enough, but you want to get high-quality sound from the radio, the best way out is to contact the appropriate car dealership or workshop. Professionals use special equipment for tuning, which allows to achieve optimal quality for specific model saba.

Is it possible to convert an active subwoofer into a passive one?

Home craftsmen often put their own knowledge into practice. For them, improving the sound of a car's sound system is often not just a task to be completed, but a kind of challenge and an interesting adventure. Moreover, if you clearly understand the design of an active and passive subwoofer, then this similar alteration is not something complicated. For this, you will need:

Active subwoofer enclosure. You can use an old, outdated and building system.
An amplifier with bass and treble characteristics of 50 and 50–250 Hz, respectively. Power - 4 ohms. Bass boost up to 12 dB.
Wires - power, tulips.
Glue Moment, sealant.
Knife, screwdrivers, chisel and mallet.

The purpose of the work: to turn an active subwoofer that does not please with its sound, or simply does not work, into a passive model with better sound quality.

Stages of work on converting an active subwoofer into a passive one

Often, car owners face the task of creating a subwoofer for a car with their own hands. Often, the simplest option is chosen for this - converting an active subwoofer into a passive one. Since the standard amplifier of the active subwoofer does not suit, or simply does not work, its use is impractical. It is better to use 2 of the four channels to bridge the subwoofer, which will increase the sound power and improve the quality. Getting Started:

Carefully disassemble the subwoofer. It is important not to damage the wooden box. To do this, use a chisel and a mallet to open the back cover. After exposing the space, you can see what the subwoofer is like inside - a box with numerous partitions;
Wooden partitions need to be knocked out. The space of the box must remain completely empty;
Now the cover is cut to the size of the wall of the former active subwoofer. The material is thick plywood. Previously, a hole is cut in the back cover for the output of the speaker connection wire;
The wall should be strengthened with self-tapping screws and glue Moment. The joints are carefully lubricated for better adhesion and to prevent debris and air from getting inside;
A speaker is inserted into the round hole. The wire is preliminarily brought out through the back wall through the hole, which is then carefully sealed. Contacts are fixed on the corresponding holder, glued or screwed on self-tapping screws, on the back cover of the future passive subwoofer;
Now connection. Tulips are inserted into the corresponding sockets of the car radio. The ends are bridged to the subwoofer. It is important to observe the polarity.

So, is it possible to turn an active subwoofer into a passive one? Can! Of course, its sound will also depend on other components of the system (amplifier, crossover), and in direct comparison, the sound quality may be inferior to branded systems. However, this option will cost significantly less than purchasing a new subwoofer, and the opportunity to demonstrate the presence of straight arms should not be underestimated either.