The frequency response is one of the most often found parameter in order to characterize audio amps. Even so, it can often be deceptive and might not really provide a good indication of the audio quality. In order to help you make a smarter buying decision, I am going to clarify what this spec means and how to understand it. This I hope is going to ensure you're going to get the perfect amplifier for your project.

Apparently there are lots of methods which producers use when specifying the frequency response. The conventional convention is to show the frequency range inside which the amplification will decrease a maximum of 3 dB from the nominal gain.

It seems like there are various approaches which manufacturers employ whilst specifying the frequency response. The most widely used technique is to describe the frequency response as the frequency range within which the amplifier has fairly constant amplification having a maximum decrease of 3 decibel (dB). Commonly the decline in gain is greatest at the upper and lower frequency. However, the frequency response quite often is utilized to misinform consumers by stretching out the frequency range a great deal beyond the range in which the amp still works effectively and also conceals the reality that the amplifier might not be linear. Ideally you should really seek to obtain a frequency response diagram from the maker. In this diagram, you will see how the amplifier behaves within the frequency response range. Additionally you can spot any peaks and valleys the amp could have. Peaks and valleys leads to colorization of the music. If possible the amp ought to have a constant amplification within the complete frequency response aside from the drop off at the upper and lower limit. Aside from the frequency response, a phase response chart may also tell a good deal in regards to the overall performance as well as sound quality of the amp.

You additionally want to look at the conditions under which the frequency response was measured. You typically will not find any specifics about the measurement conditions, however, in the manufacturer's data sheet. One condition that might effect the frequency response is the impedance of the loudspeaker attached to the amp. Standard speaker impedances vary from 2 to 16 Ohms. The lower the loudspeaker impedance the greater the load for the amp. Typically contemporary digital or "Class-D" amplifiers can have changes in the frequency response with various loads. The main reason is the fact that Class-D amplifiers use switching FETs as the power phase that produce significant amounts of switching components. These components are removed by a filter which is part of the amplifier. A changing speaker load will affect the filter response to some degree. Normally the lower the loudspeaker impedance the lower the maximum frequency of the amplifier. Moreover, the linearity of the amplifier gain will be determined by the load.

Various amplifier topologies offer a mechanism to compensate for changes in the amplifier gain with different speaker loads. One example of these methods uses feedback. The amplifier output signal following the interior lowpass is input to the amplifier input for comparison. If not designed adequately, this approach might cause instability of the amplifier however. Other amps use transformers and offer outputs for different loudspeaker loads. Aside from improving upon the frequency response of the amp, this approach generally furthermore improves the amplifier efficiency.