Do Digital Wireless Surround Speakers Have A Reduced Sound Distortion As Compared With Analogue Loudspeakers?

In this essay, I will explain the specification “total harmonic distortion”, often also named “THD” which is frequently used in order to show the performance of wireless loudspeakers.

It is often complicated to select a suitable set of wireless outdoor speakers highlighted at http://www.amphony.com given the great amount of models. Aside from looks, you will often be confronted with having to consider some of the technical specs. A few of those are most likely comparatively easy to comprehend like “output power” or “frequency response”. Yet, a spec which is not as easily understood is the spec relating to how much distortion the speaker has. In a nutshell, THD describes the difference between the sound which is produced by the loudspeaker versus the audio signal with which the loudspeaker is driven. The most widespread methods to state distortion are percent in addition to decibel. These 2 conventions can be translated into one another. If a loudspeaker specifies a distortion of 10% as an example then one tenth of the energy radiated by the loudspeaker is distortion. A distortion of 10% may also be expressed as -20 dB. 1% distortion equals -40dB.

A wireless speaker in fact has a few components that add to harmonic distortion. One of these is the built-in power amplifier. This audio amplifier is driving the speaker element. Customarily the larger the amp is driven the bigger the level of amplifier distortion. For this reason, a few producers will list amp distortion depending on amp output power. Distortion specifications for various output power levels are generally given for a number of power levels or as a chart showing distortion versus output power. Both of these techniques allow to better evaluate the performance of the amp.Furthermore, please understand that distortion usually is measured for a specific test tone frequency. Typically a 1 kHz sine wave tone is used during the measurement. Nevertheless, amplifier distortion will usually increase with increasing frequency, especially in digital class-D models.

Distortion is additionally caused via the loudspeaker driver itself. Many speakers use a driver which carries a coil. This coil is placed in a magnetic field. The voicecoil will follow the magnetic field that is controlled by the music signal to move the diaphragm. Nonetheless, this movement is not entirely linear. As such the result is distortion brought about by the speaker element. Most manufacturers will specify harmonic distortion based on the power level as usually the higher the loudspeaker is driven the higher the level of distortion. As such both the amp and the speaker element itself contribute to distortion. In addition, there are other factors which also contribute to distortion. The whole amount of distortion is the total of all of these factors. The enclosure of the loudspeaker will shake to some extent depending on the sound pressure level. These vibrations are going to also be non-linear in nature and contribute to distortion.

In order to figure out the overall distortion of a loudspeaker, a signal generator is used that supplies an ultra-linear signal to the speaker in addition to a measurement microphone that is attached to an audio analyzer in order to calculate the level of harmonics radiated by the loudspeaker. Intermodulation distortion analysis is a different method which offers a better picture of the loudspeaker distortion performance with real-world signals through using a test signal with 2 harmonics and measuring how many harmonics at different frequencies are produced by the loudspeaker. Wireless loudspeakers will also have some level of distortion during the audio transmission. The level of distortion is going to depend on the kind of cordless transmission technique and the quality of components. Generally 900 MHz FM transmitters have among the largest amount of distortion. Better models are going to use digital transmission and transmit at 2.4 GHz or 5.8 GHz to reduce audio distortion.

How Can Innovative Wireless Speakers Deal With Interference?

Wireless audio is becoming popular. A large number of consumer products for example wireless speakers for android phone are eliminating the cable plus offer greatest freedom of movement. I am about to look into how most up-to-date wireless technology are able to deal with interference from other transmitters and just how well they will work in a real-world situation.

The buzz of wireless devices including wireless speakers is responsible for a quick increase of transmitters which broadcast in the preferred frequency bands of 900 MHz, 2.4 GHz as well as 5.8 Gigahertz and thus wireless interference has become a major problem.

The most cost effective transmitters normally transmit at 900 MHz. They operate similar to FM stereos. Since the FM transmission has a small bandwidth and thereby only uses up a small fraction of the available frequency space, interference may be avoided through changing to a different channel. Digital audio transmission is normally employed by modern-day sound systems. Digital transmitters normally work at 2.4 GHz or 5.8 GHz. The signal bandwidth is higher than 900 MHz transmitters and thus competition in these frequency bands is high.

Frequency hopping products, however, are going to still cause problems given that they will disrupt even transmitters using transmit channels. Audio can be regarded as a real-time protocol. As such it has stringent demands concerning reliability. In addition, small latency is vital in many applications. Thus more advanced means are needed to ensure reliability.

One of these techniques is referred to as forward error correction or FEC for short. The transmitter is going to transmit extra information besides the audio data. The receiver makes use of a formula that makes use of the additional data. When the signal is corrupted during the transmission due to interference, the receiver can filter out the erroneous data and restore the original signal. This technique works if the level of interference won’t rise above a specific threshold. Transmitters utilizing FEC can transmit to a multitude of cordless devices and does not need any feedback from the receiver. Another technique utilizes bidirectional transmission, i.e. every receiver transmits information back to the transmitter. This strategy is only practical if the quantity of receivers is small. In addition, it requires a back channel to the transmitter. The information packets include a checksum from which each receiver can determine whether a packet was received correctly and acknowledge proper receipt to the transmitter. Because lost packets will have to be resent, the transmitter and receivers have to hold information packets in a buffer. This is going to create an audio latency, also called delay, to the transmission which is often an issue for real-time protocols like audio. Normally, the larger the buffer is, the larger the robustness of the transmission. Video applications, nevertheless, need the audio to be synchronized with the video. In cases like this a big latency is difficult. One limitation is that systems in which the receiver communicates with the transmitter usually can merely transmit to a small number of wireless receivers. Also, receivers must incorporate a transmitter and generally use up additional current Often a frequency channel may become occupied by another transmitter. Preferably the transmitter can understand this fact and change to another channel. To do so, a number of wireless speakers consistently monitor which channels are available so that they can quickly change to a clear channel. The clear channel is selected from a list of channels which has been determined to be clean. One modern technology that employs this transmission protocol is named adaptive frequency hopping spread spectrum or AFHSS

Tips On How To Save Money While Choosing Wireless Speakers Systems For Out Of Doors

In this article, I will highlight the term “total harmonic distortion”, often also named “THD” which is frequently used in order to show the quality of cordless loudspeakers.

Looking for the perfect model from the enormous number of models, you might have a difficult time understanding a few of the technical language and terms which you are going to see in the specifications of today’s cordless speakers. Total harmonic distortion is typically not very well understood. Nonetheless, this term is nonetheless important by way of determining the performance of a specific type. Other specs, such as “output power” or “frequency response” are normally easier understood. THD is expressed either in percent or in decibel and indicates how much the signal that the loudspeaker outputs deviates from the audio signal that is input into the speaker. A -20 dB or 10% distortion means that one tenth of the radiated audio is a consequence of distortion while -40 dB or 1% would mean that one percent of the energy are harmonic products of the original audio. Nonetheless, be cautious because there are in reality a number of components which bring about harmonic distortion. Cordless loudspeakers (Read more here concerning bluetooth outdoor speakers) as well as any type of active speaker or active subwoofer all have built-in power amps in order to drive the speaker element. Normally the larger the amplifier is driven the larger the level of amp distortion. For this reason, a number of suppliers will show amp distortion based on amp output power.

Distortion specifications for various power levels are generally shown for several output power levels or as a chart listing distortion versus output power. Both of these methods allow to better evaluate the quality of the amplifier.Also, please understand that distortion usually is measured for a specific test tone frequency. Commonly a 1 kHz sine wave tone is used during the measurement. Distortion, however, is usually dependent on the audio frequency. Many amps are going to have rising distortion with rising frequency. Particularly digital class-D amps are going to have rather high distortion at frequencies above 5 kHz.

Distortion is additionally caused by the loudspeaker driver itself. Most speakers use a driver which carries a voicecoil. This voicecoil is positioned in a magnetic field. The magnetic field is excited by the music signal. The variation in magnetic flux, though, is not completely in sync with the audio signal resulting from core losses in addition to other factors. Also, the kind of suspension of the diaphragm will cause nonlinear motion. This results in the audio being distorted by the loudspeaker element itself. Moreover, the bigger to power level with which the speaker is driven, the bigger the distortion. Frequently loudspeaker producers will publish distortion for small to moderate output power levels only.

As such both the amplifier and also the speaker element itself contribute to distortion. Additionally, there are other factors that also contribute to distortion. The whole amount of distortion is the total of all of these factors. The enclosure of the speaker is going to shake to some extent depending on the sound pressure level. These vibrations will also be non-linear in nature and add to distortion. Overall distortion is best determined via measurement. A signal generator is utilized which supplies a highly linear sine tone to the loudspeaker. The sound is received by a measurement microphone. The microphone signal is subsequently analyzed by an audio analyzer. The audio analyzer is going to calculate the amount of higher harmonics or distortion. Intermodulation distortion analysis is another method that gives a better picture of the loudspeaker distortion performance with real-world signals through using a test signal with 2 harmonics and measuring how many harmonics at other frequencies are generated by the speaker.

In addition, please note that the majority of wireless speakers are going to experience signal distortion during the audio transmission itself. This is for the most part the case for transmitters that employ analog or FM type transmission. Improved types will use digital transmission and transmit at 2.4 GHz or 5.8 GHz to reduce audio distortion. Moreover, go look at http://www.metacafe.com/watch/10430207/kef_kht5005_2_5_1_home_theater_speaker_system_black/.

Just How Do Bluetooth Music Receivers Compare To Bluetooth Speakers?

Modern-day cellular phones enable you to store as well as watch films and audio. A lot of people work with headphones in order to enjoy the music saved on their smartphones. Generally a lot of these earphones tend to be distributed together with your phone. While these types of headphones tend to be compact and convenient to take with you, nearly all of these kinds of mini headphones possess relatively poor sound quality, sadly. Yet, you may achieve much greater audio quality simply by transmitting your music to a set of speakers. Connecting your loudspeakers to a mobile phone via a cord is frequently not attractive. You can actually trip over the wire plus the cell phone is tethered to your stereo speakers. In this article I’ll investigate a few cordless options for streaming your audio to some loudspeakers. Nearly all stereo speakers have a lot greater sound quality than mini headphones and therefore are usually a much better choice for listening to music with your cellphone. There are actually several alternatives for streaming your songs to the loudspeakers. I’m mostly looking at wireless solutions given that you wouldn’t want your cell phone to be tethered to the stereo speakers. One of the most common choices designed for sending tunes to some loudspeakers are Bluetooth music receivers. Bluetooth is backed by almost all of modern smartphones on the market. Bluetooth music receivers can pick up the music which is streamed from the cell phone and turn the wireless signal to sound. Bluetooth supports quite a few protocols intended for sending tunes. A2DP as well as AptX are among the most popular protocols. AptX, however, is just supported by the latest generation of mobile phones while A2DP is compatible with nearly all mobile handsets.

An important deliberation over using Bluetooth music receivers is that they may only connect to active speakers. Alternatively you may utilize a sound amp. Integrated Bluetooth cordless amplifiers, however, don’t need a separate power amplifier. The cordless range of these receivers is usually only around 30 ft. So don’t consider utilizing these for transmitting tunes all through your residence. The working range may change dependant upon your environment and also the level of wireless interference. Bluetooth is in fact understood by plenty of devices apart from cellphones. To stream audio from a PC, for instance, you may additionally work with a wireless amplifier.

A different option is Airplay. Airplay is an Apple specific format which permits sending of uncompressed music. However, remember that the tracks located on your phone is usually compressed via the MP3 or AAC standard and as a result using Airplay is not going to boost the sound quality. If on the other hand you have uncompressed audio available then working with Airplay makes a lot of sense. AptX is a compromise between the common A2DP standard and Airplay. AptX is a good substitute to Airplay since it is not Apple proprietary. It does offer better audio quality than many other protocols including A2DP. In addition, it is understood by recent mobile devices.

Bluetooth cordless stereo speakers are actually one more option intended for playing tracks stored on a cell phone. There are actually plenty of models available. Bluetooth stereo speakers are normally fairly small. Therefore, they typically lack in terms of sound quality. Try out any model before buying any kind of Bluetooth stereo speakers for you to steer clear of an unpleasant surprise. To achieve the greatest sound quality, using a standalone Bluetooth audio receiver is thus a great idea. You can pick any speaker which you like. If you have a preference for mobility and go with a Bluetooth loudspeaker, check that it works with your specific smartphone first.

A Short Primer For Audio Amplifiers

Requirements regarding audio power and audio fidelity of today’s speakers and home theater products are constantly increasing. At the heart of these products is the stereo amplifier. Recent music amps have to perform well enough to meet those ever increasing requirements. With the ever increasing amount of models and design topologies, like “tube amps”, “class-A”, “class-D” and “t amplifier” designs, it is getting more and more demanding to select the amplifier which is ideal for a particular application. This post will describe a few of the most widespread terms and clarify some of the technical jargon which amplifier manufacturers frequently employ.

Simply put, the use of an audio amplifier is to convert a low-power audio signal into a high-power music signal. The high-power signal is great enough to drive a loudspeaker sufficiently loud. Depending on the type of amplifier, one of several kinds of elements are utilized to amplify the signal such as tubes as well as transistors.

A couple of decades ago, the most widespread type of audio amp were tube amplifiers. Tube amplifiers utilize a tube as the amplifying element. The current flow through the tube is controlled by a low-level control signal. Thereby the low-level audio is converted into a high-level signal. Sadly, tube amps have a somewhat high level of distortion. Technically speaking, tube amps will introduce higher harmonics into the signal. These days, tube amps still have a lot of fans. The primary reason is that the distortion that tubes produce are often perceived as “warm” or “pleasant”. Solid state amps with low distortion, on the other hand, are perceived as “cold”.

Furthermore, tube amps have fairly low power efficiency and thus radiate much power as heat. In addition, tubes are pretty expensive to manufacture. Therefore tube amplifiers have by and large been replaced by solid-state amps which I will glance at next. Solid state amplifiers replace the tube with semiconductor elements, usually bipolar transistors or FETs. The earliest type of solid-state amplifiers is often known as class-A amps. In a class-A amp, the signal is being amplified by a transistor which is controlled by the low-level audio signal. Class-A amps have the smallest distortion and generally also the smallest amount of noise of any amplifier architecture. If you need ultra-low distortion then you should take a closer look at class-A models. The main disadvantage is that much like tube amplifiers class A amps have quite low efficiency. Because of this these amps require big heat sinks to radiate the wasted energy and are frequently fairly bulky. By utilizing a series of transistors, class-AB amps improve on the low power efficiency of class-A amps. The operating area is split into two distinct areas. These 2 regions are handled by separate transistors. Each of those transistors operates more efficiently than the single transistor in a class-A amp. As a result of the larger efficiency, class-AB amplifiers do not require the same number of heat sinks as class-A amplifiers. As a result they can be manufactured lighter and cheaper. However, this architecture adds some non-linearity or distortion in the region where the signal switches between those areas. As such class-AB amps normally have larger distortion than class-A amplifiers.

In order to further improve the audio efficiency, “class-D” amplifiers utilize a switching stage which is continuously switched between two states: on or off. None of these two states dissipates power inside the transistor. As a result, class-D amps frequently are able to attain power efficiencies higher than 90%. The on-off switching times of the transistor are being controlled by a pulse-with modulator (PWM). Standard 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. Typically a simple first-order lowpass is being used. The switching transistor and in addition the pulse-width modulator frequently exhibit fairly big non-linearities. As a result, the amplified signal is going to contain some distortion. Class-D amplifiers by nature exhibit larger audio distortion than other kinds of mini stereo amplifiers.

Modern amplifiers include internal audio feedback to minimize the amount of audio distortion. “Class-T” amplifiers (also known as “t-amplifier”) make use of this kind of feedback method and thus can be made extremely small while achieving low music distortion.

Just How Do Current Wireless Speakers Overcome Interference?

I’ll take a look at how modern-day audio transmission technologies that are utilised in today’s wireless loudspeakers operate in real-world situations having a large amount of interference from other cordless gadgets.

The increasing rise in popularity of cordless consumer systems like wireless speakers has begun to cause problems with numerous devices competing for the restricted frequency space. Wireless networks, cordless telephones , Bluetooth as well as other devices are eating up the valuable frequency space at 900 MHz and 2.4 GHz. Wireless sound systems must ensure robust real-time transmission in an environment having a large amount of interference. The least expensive transmitters normally broadcast at 900 MHz. They work much like FM radios. Because the FM transmission uses a small bandwidth and thereby just consumes a small part of the available frequency space, interference is generally eliminated through changing to another channel. Digital audio transmission is frequently utilized by modern-day sound products. Digital transmitters usually work at 2.4 Gigahertz or 5.8 GHz. The signal bandwidth is higher than 900 MHz transmitters and thus competition in these frequency bands is high.

Simply switching channels, nonetheless, is no reliable solution for staying away from specific transmitters which use frequency hopping. Frequency hoppers including Bluetooth devices as well as numerous wireless phones will hop through the entire frequency spectrum. As a result transmission over channels is going to be disrupted for short bursts of time. As a result modern audio transmitters incorporate special mechanisms to deal with interfering transmitters to assure continuous interruption-free sound transmission.

One approach is known as FEC or forward error correction. This technique allows the receiver to repair a corrupted signal. For this purpose, extra data is sent from the transmitter. The receiver employs an algorithm which uses the additional data. In the event the signal is damaged during the transmission as a result of interference, the receiver can easily remove the invalid data and restore the original signal. This method will work if the level of interference won’t go above a specific threshold. Transmitters employing FEC may broadcast to a huge amount of wireless devices and doesn’t need any feedback from the receiver. One more method uses bidirectional transmission, i.e. every receiver sends data back to the transmitter. This approach is only helpful if the quantity of receivers is small. In addition, it requires a back channel to the transmitter. The information which is broadcast has a checksum. From this checksum the receiver can easily decide if any particular packet was received correctly and acknowledge. Given that lost packets will have to be resent, the transmitter and receivers need to store data 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 bigger buffer size improves the stability of the transmission. Video applications, nevertheless, need the sound to be in sync with the movie. In this instance a large latency is a problem. Wireless products that incorporate this method, however, can only transmit to a restricted number of wireless receivers. Generally the receivers have to be paired to the transmitter. Since each receiver also requires transmit functionality, the receivers are more pricey to produce and in addition use up more energy. Often a frequency channel can become occupied by another transmitter. Preferably the transmitter will realize this fact and change to another channel. To achieve this, a few wireless speakers consistently monitor which channels are available to enable them to quickly change to a clear channel. The clean channel is selected from a list of channels that has been identified to be clear. A modern technology that uses this transmission protocol is named adaptive frequency hopping spread spectrum or AFHSS