Are you considering to pick a couple of wireless speaker system products? You may be baffled by all of the technical language used by makers to exhibit the performance of their products. I will highlight one regularly used term which, however, ist often misunderstood: “total harmonic distortion” or “THD”.

It is often difficult to pick a suitable pair of wireless surround sound speakers given the great amount of models. Aside from looks, you will often be faced with having to study several of the technical specs. THD is generally not as easily understood as various other frequently utilized specs including “signal-to-noise ratio” or “frequency response”.

In brief, “harmonic distortion” describes how much the audio signal is being deteriorated because of the loudspeaker or in other words how much the signal differs from the original signal. There are two common methods to state harmonic distortion, either in percent (%) or in decibel (dB). If a loudspeaker specifies a distortion of 10% to provide an example then one tenth of the energy radiated by the speaker is distortion. A distortion of 10% may also be stated as -20 dB. 1% distortion equals -40dB.

Harmonic distortion in a cordless loudspeaker is actually the result of several elements, such as the power amp that is built into the loudspeaker to drive the loudspeaker element. Normally the bigger the amplifier is driven the higher the level of amplifier distortion. For this reason, a few suppliers will list amp distortion depending on amplifier power.

Distortion ratings for different power levels are normally given for several power levels or as a diagram showing distortion versus output power. Both of these methods allow to better evaluate the quality of the amp.Harmonic distortion measurements are usually done by feeding a test signal into the loudspeaker. This tone is a pure sine wave signal with minimum distortion. The frequency of this test tone is normally 1 kHz. Still, amplifier distortion is going to generally increase with increasing frequency, especially in digital class-D models.

A different component causing distortion is the speaker element that normally works with a diaphragm that carries a coil that is suspended 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 music signal as a result of core losses and other factors. In addition, the kind of suspension of the diaphragm will create nonlinear movement. This results in the audio being distorted by the loudspeaker element itself. Also, the bigger to power level with which the loudspeaker is driven, the bigger the distortion. Regularly speaker suppliers will show distortion for small to moderate output power levels only.

The total distortion of the loudspeaker therefore is the sum total of the amplifier distortion along with the speaker element distortion. In addition, there are different contributing factors. The speaker enclose will shake to some extent and thus contribute to the distortion.

The total distortion of the loudspeaker is ordinarily determined by a measurement that consists of a low-distortion audio generator plus a microphone which is connected to an audio analyzer. The audio analyzer will calculate the level of higher harmonics and compare these with the main signal to compute the distortion. Intermodulation distortion analysis is another method that offers a better picture of the loudspeaker distortion performance with real-world signals by utilizing a test signal with two harmonics and measuring how many harmonics at other frequencies are produced by the speaker.

Cordless speakers are going to also have some amount of distortion during the audio transmission. The amount of distortion will depend on the type of wireless transmission method and the quality of components. Typically 900 MHz FM transmitters have among the largest amount of distortion. Better products are going to utilize digital transmission and transmit at 2.4 GHz or 5.8 GHz to reduce audio distortion.

Similar Posts: