Cordless loudspeaker vendors frequently show the frequency response of their products. The data that is published will not automatically show you a great deal about the audio quality. I will shed light on the meaning of this term and even provide a few recommendations on how to interpret it while looking for a set of cordless speakers.
Cordless speakers are only able to work within a specific frequency range. Any signals outside this range will be removed. As a result the frequency response provides a significant clue whether a set of wireless loudspeakers might be well suited for a specific use. Usually a lower and upper frequency are listed, like 20 Hz – 20 kHz. This kind of spec suggests that the cordless speakers have the ability to transmit and then reproduce music within that frequency range. You might be tempted to choose a set of wireless loudspeakers that gives the largest frequency response. Then again, there is much more to know about a wireless loudspeakers’ performance than this simple range.
It appears there are numerous approaches that companies employ whilst specifying the frequency response. The most common way is to describe the frequency response as the frequency range within which the wireless speakers will have rather constant sound pressure level with a highest drop of 3 decibels (dB). Usually the drop in sound pressure level is greatest at the lower and upper frequency.
Then again, the frequency response frequently is utilized in order to mislead shoppers by way of stretching out the frequency range a good deal beyond the range in which the wireless speakers still work effectively and also hide the fact that the wireless loudspeakers might not be linear within that range. It is best to have a complete frequency response document. This type of graph will show whether or not there are any kind of significant peaks and valleys inside the working frequency range. Peaks along with valleys can cause colorization of the music. If possible the wireless loudspeakers needs to have a constant sound pressure level inside the whole frequency response except for the drop off at the upper and lower limit. In addition to the frequency response, a phase response chart may also say a great deal in regards to the overall performance and also audio quality of the wireless speakers.
To better comprehend the frequency response behavior of a particular model, you should try to figure out under which conditions the response was measured. You will probably find this info in the data sheet of the wireless speakers. However, a lot of suppliers will not publish these in which case you ought to get in touch with the maker directly.
Most cordless speakers use digital amps, referred to as Class-D amplifiers. Class-D amplifiers use a lowpass filter within their output as a way to suppress the switching components which are produced from the internal power FETs. The lowpass filter characteristic, however, heavily depends upon the connected speaker load.
A few of the newest digital amplifiers feed back the music signal after the lowpass filter to compensate for this drawback and also to make the frequency response of the amplifier independent of the attached driver load. On the other hand, if the amp is not constructed properly, this kind of feedback could potentially cause instability and lead to loud noise being generated by the amp if certain speakers are connected. Another approach makes use of audio transformers between the power stage of the amp and several outputs. Every output is designed to connect a different loudspeaker load. This approach makes sure that the amplifier is going to be loaded equally and in addition increases amplifier efficiency.