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: http://www.articlesalley.com/article.detail.php/334347/191/Electronics/Technology/38/Ditch_The_Wires_And_Be_Free_With_Wireless_Speakers_for_tv.