Things To Understand About Wireless Speaker Energy Efficiency


In this commentary, I will explain the term “total harmonic distortion”, often also titled “THD” which is frequently used to show the performance of cordless loudspeakers.

Cordless loudspeakers are available in all different shapes and sizes. Picking the correct type can frequently be difficult . I am going to shed some light on one commonly used term that is used in order to show the technical performance of the loudspeaker: “total harmonic distortion” or “THD”. A number of of these are probably pretty simple to comprehend for instance “output power” or “frequency response”. Yet, a term which is not as easily understood is the term relating to how much distortion the speaker has.

In short, “harmonic distortion” shows how much the music signal is being deteriorated because of the speaker or in other words how much the signal differs from the original signal. There are 2 widespread methods in order to express harmonic distortion, either in percent (%) or in decibel (dB). The percentage given as THD describes which amount of energy that is radiated by the speaker are higher harmonics versus the original signal. 10% would mean that one 10th is distortion. 1% would mean one hundredth etc. 10% equals -20 dB whilst 1% equals -40 dB.

Harmonic distortion in a cordless loudspeaker is in fact the result of numerous components, including the power amp that is built into the speaker in order to drive the speaker element. Amplifier distortion generally depends on the amp output power and is from time to time specified for a few power levels. Having amp distortion specifications for a few output power levels gives a better indication of the amp distortion performance.Generally distortion is measured with a 1 kHz test tone. However, amplifier distortion will usually increase with increasing frequency, especially in digital class-D types.

The second contributing factor is the loudspeaker element itself. The majority of speakers (go right here to study useful resources concerning stereo speakers) employ a diaphragm kind driver that is driven by a coil which is suspended in a magnetic field. The coil will follow the magnetic field which is controlled by the music signal to move the diaphragm. Yet, this movement is not completely linear. As such the result is distortion brought about by the loudspeaker element. The majority of suppliers will publish harmonic distortion depending on the audio level as normally the higher the loudspeaker is driven the higher the level of distortion.

The total distortion of the speaker thus is the total of the amplifier distortion in addition to the speaker element distortion. Furthermore, there are other contributing factors. The loudspeaker enclose will vibrate to some extent and therefore contribute to the distortion. Total distortion is best determined by measurement. A signal generator is utilized which offers a highly linear sine tone to the speaker. The sound is picked up by a measurement microphone. The microphone signal is then analyzed by an audio analyzer. The audio analyzer will calculate the level of higher harmonics or distortion. However, pure sine signals hardly give an accurate indication of the distortion of the wireless loudspeaker with real-world signals. A better distortion analysis is the so-called intermodulation distortion analysis in which a test tone which consists of a number of sine waves is used. Then the level of harmonics at other frequencies is calculated.

Cordless speakers are going to also have some amount of distortion during the audio transmission. The level of distortion will depend on the type of cordless transmission method as well as the quality of components. Generally 900 MHz FM transmitters have among the largest amount of distortion. Digital audio transmission on the other hand offers the least amount of audio distortion. The music is sampled inside the transmitter and not affected throughout the transmission itself. Digital wireless audio transmitters are available at 2.4 GHz and 5.8 GHz. On top of that, visit the following web page:


Methods To Make Sure That Your Network Speakers Will Last

If you recently purchased a home theater system or a pair of cordless speakers, you may require some suggestions on correctly setting it up if you don’t want to contract an installer. You may think you are technically savvy and that installing your new home theater system will be a snap. I am going to offer several recommendations that will help you steer clear of some usually made errors.

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After unpacking your new home theater system, you are going to generally find one central component and five or seven loudspeakers. The main component is going to deliver the signal for every one of your loudspeakers that you are going to install. This central component is also called surround sound receiver or amplifier. It is the central hub of your home theater system. Put this receiver in a place that minimizes the loudspeaker cord run to each loudspeaker. Just be sure it is in a dry and safe place. Moreover, be certain that you can easily reach the receiver from your television set or DVD/Blue-ray player because you will need to connect these. The receiver requires an audio signal in order to deliver surround sound. Normally it is going to accept an optical surround sound signal. You may connect this input to your television set by using a fiberoptical cable. This cable is usually included with your system. You can also get it a most electronics stores. After you have established the audio link to your television set, you may now proceed and attach your loudspeakers. This step requires a bit more work.

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If you have cordless rear speakers you will not need as much speaker cable and the install is going to be somewhat easier. First of all, measure how much speaker cord you are going to need. Make sure to add some extra cable in order to take into account those twists and corners. If you are planning to drive a lot of output power to your speakers then make sure you choose a cord which is thick enough to handle the current flow. Your woofer normally is going to be an active woofer. This means that it is going to accept a low-level music signal. You can attach your subwoofer via an RCA cable.

wireless speakers

Whilst attaching the speaker cord, be sure that you attach the cord with the accurate polarity. Each speaker offers a color-coded terminal, generally red and black. Choose a loudspeaker cable which is color coded to help ensure the correct polarity while attaching to the speaker terminal. In the same way, watch the correct polarity while connecting the speaker cord to your surround receiver to keep all of your loudspeakers in phase. If you are using wireless speakers, there will be a short audio delay incurred throughout the audio transmission to the speakers, also known as latency. Normally the latency ranges between one and twenty ms. For best result, it is best if all of the loudspeakers are in sync. If you have cordless rears then the audio will by to some extent out of sync with your remaining speakers. To keep all speakers in sync you are going to have to tweak the receiver to delay the signal going to your wired loudspeakers.

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Check the user manual in order to find out how to set a delay on specific channels. Home theater systems that were not intended for cordless rear speakers might not come with this capability. In this case you may want to look for a wireless speaker kit which has very low latency, ideally less than one ms. This will keep all of your loudspeakers in perfect sync.

A Peek At Various Important Loudspeaker Technical Specs

In this commentary, I am going to explain the spec “total harmonic distortion”, often also referred to as “THD” which is often used in order to show the quality of wireless speakers shown at this hyperlink.

Wireless loudspeakers are available in all different shapes and sizes. Selecting the right type may often be difficult . I will shed some light on a frequently used spec which is utilized to publish the technical quality of the speaker: “total harmonic distortion” or “THD”. THD is generally not as easily understood as a few other commonly utilized specs including “signal-to-noise ratio” or “frequency response”. Briefly, “harmonic distortion” shows how much the music signal is being degraded as a result of the speaker or in other words how much the signal differs from the original signal. There are two common methods in order to articulate harmonic distortion, either in percent (%) or in decibel (dB). A -20 dB or 10% distortion means that one 10th of the radiated audio is a consequence of distortion whilst -40 dB or 1% would mean that one percent of the energy are harmonic products of the original signal. Though, be careful because there are in fact several elements which cause harmonic distortion. Cordless loudspeakers along with any type of active loudspeaker or active subwoofer all have built-in power amplifiers in order to drive the loudspeaker element. The amp itself will have a specific level of distortion. Typically the distortion of the amplifier will be bigger the more output power it supplies to the loudspeaker. In general producers are going to publish amplifier distortion based on a specific level of output power, normally a lot less than the rated highest amp output power.

wireless speakers

Distortion ratings for various power levels are usually specified for a few output power levels or as a diagram listing distortion versus output power. Both of these methods allow to better evaluate the quality of the amplifier.Furthermore, please note that distortion generally is measured for a certain test tone frequency. Commonly a 1 kHz sine wave tone is utilized during the measurement. This allows comparing equipment from various vendors. However, distortion normally varies with different frequencies. Many digital amps are going to exhibit growing distortion amid higher frequency which can not easily be discovered through glancing at the specification sheet.

wireless speakers

One more component causing distortion is the speaker element that generally works with a diaphragm that carries a voicecoil that is suspended in a magnetic field. The voicecoil will track the magnetic field which is controlled by the audio signal in order to move the diaphragm. Yet, this movement is not completely linear. As such there will be speaker element distortion which additionally depends on the amount of power with which the speaker is driven.

The total distortion of the speaker thus is the sum of the amp distortion along with the speaker element distortion. Moreover, there are other contributing factors. The loudspeaker enclose will vibrate to some extent and thus add to the distortion.

wireless speakers

To figure out the overall distortion of a speaker, a signal generator is utilized which provides an ultra-linear signal to the loudspeaker and also a measurement microphone that is attached to an audio analyzer to calculate the amount of harmonics radiated by the loudspeaker. However, pure sine signals barely give an accurate picture of the distortion of the wireless speaker with real-world signals. A better distortion analysis is the so-called intermodulation distortion analysis where a test tone that includes several sine waves is used. Next the level of harmonics at different frequencies is measured.

wireless speakers

One more factor contributing to distortion is the signal transmission of wireless loudspeakers, particularly with products which broadcast an analog signal at 900 MHz. Digital audio transmission on the other hand has the least level of audio distortion. The signal is digitized in the transmitter and not affected throughout the transmission itself. Digital cordless audio transmitters are available at 2.4 GHz plus 5.8 GHz.

A Glance At How Today’s Wireless Speakers Work In Real-World Conditions

An ever expanding quantity of cordless gadgets which include wireless outdoor speakers available at is bringing about growing competition for the precious frequency space. I am going to check out a number of technologies which are utilized by the latest digital sound systems in order to see how well these solutions can work in a real-world situation. The popularity of cordless gizmos just like wireless speakers is mainly responsible for a quick rise of transmitters which transmit in the preferred frequency bands of 900 MHz, 2.4 Gigahertz and 5.8 GHz and thus cordless interference has turned into a serious issue.

The least expensive transmitters normally broadcast at 900 MHz. They work similar to FM radios. Since the FM signal uses a small bandwidth and thus only occupies a tiny part of the free frequency space, interference may be prevented by changing to a new channel. The 2.4 GHz and 5.8 Gigahertz frequency bands are used by digital transmitters and also are getting to be quite crowded lately because digital signals take up much more bandwidth as compared to analog transmitters.

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Just changing channels, on the other hand, is no dependable solution for avoiding certain transmitters which use frequency hopping. Frequency hoppers like Bluetooth gadgets as well as several cordless telephones are going to hop throughout the whole frequency spectrum. As a result transmission on channels is going to be disrupted for brief bursts of time. Audio can be viewed as a real-time protocol. Consequently it has strict requirements regarding dependability. In addition, small latency is critical in several applications. For that reason more sophisticated strategies are required to ensure reliability. One of these methods is called forward error correction or FEC for short. The transmitter is going to transmit extra data besides the audio data. The receiver uses an algorithm which utilizes the extra information. In the event the signal is damaged during the transmission as a result of interference, the receiver can easily remove the erroneous data and restore the original signal. This approach works if the amount of interference won’t go beyond a specific threshold. FEC is unidirectional. The receiver doesn’t send back any kind of information to the transmitter. As a result it is frequently employed for systems like radio receivers in which the number of receivers is large. Yet another method utilizes receivers that transmit data packets to the transmitter. The transmitters incorporates a checksum with every data packet. Every receiver can determine whether a specific packet has been received correctly or damaged because of interference. Subsequently, each cordless receiver sends an acknowledgement to the transmitter. Since lost packets must be resent, the transmitter and receivers have to store information packets in a buffer. Using buffers brings about a delay or latency in the transmission. The amount of the delay is proportional to the buffer size. A larger buffer size increases the stability of the transmission. A big latency can be a problem for several applications however. Particularly if video exists, the audio should be synchronized with the movie. Furthermore, in multichannel surround sound applications in which a number of loudspeakers are cordless, the wireless speakers should be synchronized with the corded speakers. One limitation is that systems in which the receiver communicates with the transmitter can usually just transmit to a few wireless receivers. Also, receivers have to incorporate a transmitter and generally consume additional current

Often a frequency channel may become occupied by a different transmitter. Preferably the transmitter is going to understand this fact and change to another channel. To do this, a number of wireless speakers continuously check which channels are available so that they can quickly switch to a clean channel. Since the transmitter has a list of clear channels, there is no delay in trying to find a clear channel. It’s simply picked from the list. This technique is frequently referred to as adaptive frequency hopping spread spectrum.

Just How Do Bluetooth Audio Receivers Can Rival Bluetooth Speakers?

Smartphones have changed quite a bit. A lot of handsets marketed presently usually are smart phones. Most of these smart phones provide many capabilities not available in outdated mobile phones including the means to keep and also play songs. Those earphones which are provided with mobile phones generally offer rather bad sound quality. A more suitable choice will be to play back the tracks via some stereo speakers. It is easy to attach the cell phone to a pair of loudspeakers with a headphone cable. However, you can also find some cordless alternatives on the market designed for streaming tracks to a pair of speakers. Attaching your stereo speakers to your cellphone by employing a cable is frequently not appealing. You can easily trip over the cable plus your cellular phone is connected to your stereo speakers. On this page I’ll take a look at a number of cordless alternatives designed for streaming your tracks to a pair of stereo speakers.

Loudspeakers tend to be a very good substitute to earphones that can come with a cellphone. They’ll have greater sound quality plus you are not connected to your phone. Linking your mobile phone to some stereo speakers can easily be achieved in a number of ways. You are able to connect the speakers to the smartphone through cable or wirelessly. Wireless is far more practical when compared with employing a cable. Bluetooth music receivers, for example, enable sending of tracks by way of Bluetooth. Bluetooth is recognized by virtually all of modern mobile phones. Bluetooth audio receivers can receive the tracks that is streamed from the cellular phone and turn the cordless signal back to sound. Many of modern receivers support the popular standards A2DP and also AptX. A2DP is the most frequently used standard to send tracks by using Bluetooth while AptX is only supported by the newest generation of mobile phones. One important deliberation over employing Bluetooth audio receivers is that these can only be connected to active loudspeakers. Alternatively you can easily utilize a power amp. There are furthermore some integrated receivers/amplifiers available on the market. These kinds of models usually do not need a separate power amplifier and are able to attach directly to any passive speakers. The cordless range of these receivers is typically only approximately 30 feet. So never consider using them for the purpose of transmitting tunes throughout your residence. The working range can easily change dependant upon your environment and the level of cordless interference. Bluetooth is actually supported by a lot of gadgets apart from cellular phones. If you desire to stream tunes from a Computer, for example, you can furthermore work with a Bluetooth adapter. Airplay may offer better sound quality in comparison with Bluetooth considering the fact that it can transmit uncompressed music. One of several more recent protocols employed inside Bluetooth is AptX. It will provide close to CD-quality audio sending – again assuming that you have got uncompressed audio available. This specific standard isn’t yet supported by a large number of cellular phones yet the latest Bluetooth receivers offer AptX as an choice. Yet another option for sending tracks from your mobile phone are Bluetooth cordless loudspeakers. Given that Bluetooth stereo speakers generally usually do not provide similar sound quality as some other loudspeakers, it is a wise idea to try them out just before your purchase. On top of that you need to be sure that any particular type of Bluetooth wireless loudspeakers is compatible with your smartphone just before your investment.

Purchasing A Couple Of Efficient Wireless Loudspeakers

I’ll take a look at the expression “power efficiency” that shows you how much wireless speakers waste so that you can select a pair of wireless speakers.

The less efficient your wireless speakers are, the more power will be squandered which results in a number of issues: A great deal of squandered power clearly implies larger operating cost which means that a more pricey set of wireless loudspeakers can in fact in the long run possibly be less costly than a less expensive model which has lower efficiency. Lower efficiency cordless speakers will dissipate a great deal of energy as heat. Cordless loudspeakers with small power efficiency routinely have a number of heat sinks to help dissipate the wasted power. Heat sinks and fans demand space and are expensive. The wireless speakers therefore is going to get fairly large and expensive. Additionally heat fans are going to create running noise. Low-efficiency wireless speakers further require a good amount of circulation around the wireless speakers. Thus they can not be placed in close spaces or within air-tight enclosures. Cordless loudspeakers that have low efficiency have to have a bigger power source in order to output the identical level of audio power as high-efficiency products. An increased amount of heat causes additional stress on components. The lifespan of the cordless loudspeakers may be decreased and dependability could be jeopardized. High-efficiency cordless loudspeakers in contrast do not suffer from these problems and can be built very small. The efficiency is shown as a percentage in the cordless speakers data sheet. Different amplifier topologies deliver different power efficiencies. Class-A amps are amongst the least efficient and Class-D the most efficient. Typical power efficiencies vary from 25% to 98%. The larger the efficiency figure, the less the level of power squandered as heat. A 100-Watt amplifier which has a 50% efficiency would have a power consumption of 200 W.

What is less known about efficiency is the fact that this value is not fixed. Actually it varies based on how much energy the amp delivers. As a result in some cases you can find efficiency values for different power levels in the data sheet. Every audio amplifier will consume a certain amount of energy irrespective of whether or not it supplies any kind of power to the speaker. That is why the lower the power the amplifier provides, the smaller the efficiency. As a result audio producers usually specify the efficiency for the highest audio power that the amplifier can deliver. To determine the power efficiency, the audio power that is consumed by a power resistor that is attached to the amp is divided by the total energy the amp uses while being fed a constant sine wave signal. Usually a complete power report is plotted to show the dependency of the efficiency on the output power. Due to this the output power is swept through different values. The efficiency at each value is measured plus a efficiency plot generated. When choosing a set of cordless loudspeakers you have got to weigh efficiency versus fidelity since wireless speakers which employ low-efficiency analog amplifiers often offer the largest audio fidelity whilst digital types will have bigger distortion. Having said that, digital amps have come a long way and are offering improved audio fidelity than ever before. Cordless speakers that employ Class-T amplifiers come close to the audio fidelity of types that have analog amps. Due to this fact picking a pair of cordless loudspeakers which use switching amplifier with great music fidelity is now possible.

A Quick Look At How Latest Wireless Speakers Work In Real-World Conditions

An ever growing quantity of cordless systems for example loudspeakers which are cordless is causing increasing competition for the precious frequency space. I’ll check out some systems which are used by current digital audio gadgets in order to see how well these solutions can operate in a real-world environment.

The popularity of cordless gizmos just like wireless speakers has caused a rapid rise of transmitters which broadcast in the most popular frequency bands of 900 MHz, 2.4 Gigahertz and 5.8 GHz and thus wireless interference has turned into a significant issue.

FM type audio transmitters are usually the least robust in regards to tolerating interference considering that the transmission does not have any method to deal with competing transmitters. However, those transmitters possess a rather constrained bandwidth and switching channels may steer clear of interference. The 2.4 GHz and 5.8 GHz frequency bands are utilized by digital transmitters and also are getting to be very crowded recently since digital signals take up a lot more bandwidth compared to analog transmitters.

Quite a few wireless products for instance Bluetooth devices and wireless telephones incorporate frequency hopping. Thus simply switching the channel isn’t going to prevent these kinds of frequency hoppers. Audio can be viewed as a real-time protocol. Therefore it has stringent requirements pertaining to stability. Additionally, low latency is essential in numerous applications. Therefore more innovative techniques are needed to assure dependability.

One of these approaches is known as forward error correction or FEC in short. The transmitter will transmit additional information besides the sound data. Making use of several advanced calculations, the receiver is able to restore the data which may partially be damaged by interfering transmitters. Consequently, these systems can broadcast 100% error-free even when there is interference. Transmitters utilizing FEC alone typically may transmit to any number of cordless receivers. This approach is usually employed for products in which the receiver cannot resend information to the transmitter or where the number of receivers is rather big, like digital stereos, satellite receivers and so on.

One more approach uses receivers that transmit information packets to the transmitter. The information packets include a checksum from which every receiver can determine whether a packet was received properly and acknowledge correct receipt to the transmitter. If a packet was corrupted, the receiver is going to inform the transmitter and ask for retransmission of the packet. Consequently, the transmitter must store a great amount of packets in a buffer. Equally, the receiver must have a data buffer. This buffer causes an audio delay that depends upon the buffer size with a larger buffer improving the robustness of the transmission. Video applications, however, need the sound to be in sync with the video. In this case a large latency is difficult. One constraint is that systems in which the receiver communicates with the transmitter usually can merely broadcast to a few cordless receivers. Furthermore, receivers need to add a transmitter and usually use up additional current

Often a frequency channel may become occupied by another transmitter. Preferably the transmitter is going to understand this fact and switch to another channel. To accomplish this, several wireless speakers continually check which channels are available to enable them to immediately change to a clean channel. This technique is also known as adaptive frequency hopping.

A Brief Comparison Of Stereo Amplifiers

Music amplifiers are at the very heart of every home theater system. As the quality and output power demands of modern loudspeakers increase, so do the demands of audio amps. With the ever growing amount of models and design topologies, such as “tube amplifiers”, “class-A”, “class-D” as well as “t amplifier” types, it is getting more and more demanding to pick the amp that is best for a particular application. This post will describe a few of the most common terms and spell out some of the technical jargon which amp producers regularly employ.

The basic operating principle of an audio amp is rather simple. An audio amp will take a low-level audio signal. This signal regularly originates from a source with a rather high impedance. It subsequently translates this signal into a large-level signal. This large-level signal may also drive speakers with small impedance. To do that, an amp uses one or several elements which are controlled by the low-power signal in order to create a large-power signal. Those elements range from tubes, bipolar transistors to FET transistors.

Tube amps used to be widespread several decades ago. A tube is able to control the current flow according to a control voltage that is connected to the tube. Tubes, however, are nonlinear in their behavior and are going to introduce a quite large amount of higher harmonics or distortion. Though, this characteristic of tube amplifiers still makes these popular. A lot of people describe tube amplifiers as having a warm sound as opposed to the cold sound of solid state amplifiers.

One disadvantage of tube amplifiers is their small power efficiency. In other words, most of the energy consumed by the amplifier is wasted as heat rather than being transformed into audio. For that reason tube amplifiers will run hot and require sufficient cooling. Moreover, tubes are quite costly to build. Therefore tube amplifiers have mostly been replaced by solid-state amps which I will look at next. Solid state amps replace the tube with semiconductor elements, usually bipolar transistors or FETs. The earliest type of solid-state amplifiers is called class-A amplifiers. In class-A amps a transistor controls the current flow according to a small-level signal. A number of amps use a feedback mechanism in order to minimize the harmonic distortion. Regarding harmonic distortion, class-A amplifiers rank highest among all kinds of audio amps. These amplifiers also regularly exhibit very low noise. As such class-A amplifiers are perfect for extremely demanding applications in which low distortion and low noise are crucial. Class-A amps, on the other hand, waste the majority of the energy as heat. For that reason they frequently have big heat sinks and are fairly bulky. By making use of a series of transistors, class-AB amps improve on the low power efficiency of class-A amplifiers. The operating area is divided into two distinct regions. These two areas are handled by separate transistors. Each of these transistors works more efficiently than the single transistor in a class-A amp. As such, class-AB amplifiers are generally smaller than class-A amplifiers. When the signal transitions between the 2 separate regions, however, some level of distortion is being created, thereby class-AB amplifiers will not achieve the same audio fidelity as class-A amps.

In order to further improve the audio efficiency, “class-D” amplifiers utilize a switching stage which is continually switched between 2 states: on or off. None of these 2 states dissipates energy inside the transistor. As a result, class-D amps frequently are able to achieve power efficiencies beyond 90%. The on-off switching times of the transistor are being controlled by a pulse-with modulator (PWM). Usual switching frequencies are in the range of 300 kHz and 1 MHz. This high-frequency switching signal needs to be removed from the amplified signal by a lowpass filter. Commonly a simple first-order lowpass is being used. Both the pulse-width modulator and the transistor have non-linearities that result in class-D amps having bigger audio distortion than other types of amplifiers. More recent mini stereo amps include some sort of mechanism in order to reduce distortion. One approach is to feed back the amplified audio signal to the input of the amplifier to compare with the original signal. The difference signal is subsequently used to correct the switching stage and compensate for the nonlinearity. “Class-T” amplifiers (also referred to as “t-amplifier”) use this type of feedback mechanism and for that reason can be manufactured very small whilst attaining low audio distortion.