The frequency response is by far the most commonly found parameter to characterize power amplifiers. Nonetheless, it may often be misleading and might not really give a good sign of the audio quality. You may not understand fully just how the frequency response is calculated. Let me explain what exactly this specific expression means. Ideally you'll be able to make a much more informed buying decision.
A large frequency response does not necessarily mean the amplifier offers good audio quality. For instance an amplifier having a frequency response between 30 Hz and 15 kHz might sound better than a different amplifier having a response between 10 Hz and 30 kHz. Moreover, each maker, it appears, uses a different way of specifying the lowest and highest frequency of their amplifiers. The conventional convention is to show the frequency range within which the amplification will decrease no more than 3 dB from the nominal gain.
Nevertheless, many companies dismiss this particular established practice. They push the lower frequency and upper frequency to where the amplifier barely provides any gain. Moreover, these numbers say very little about how linear the amp is working inside this range. A full frequency response chart, on the other hand, will demonstrate if there are any kind of peaks or valleys and in addition show the way the frequency response is to be understood. Peaks along with valleys may cause colorization of the sound. Ideally the gain of the amplifier should be linear over the entire working range.
This change is most apparent with most digital amps, also known as Class-D amplifiers. Class-D amplifiers employ a lowpass filter in their output to be able to reduce the switching components which are generated through the internal power FETs. Then again, the frequency response of the amplifier now depends on the speaker load because the behavior of this lowpass filter is affected by the load impedance. Generally the lower the loudspeaker load impedance the lower the upper cut-off frequency of the amp
Typically modern digital or "Class-D" amplifiers will show changes in the frequency response with different loads. The primary reason is the fact that Class-D amplifiers employ switching FETs as the power phase that create quite a lot of switching components. These components are eliminated by using a filter which is part of the amplifier. A varying loudspeaker load will impact the filter response to some extent. Commonly the lower the speaker impedance the lower the maximum frequency of the amplifier. Furthermore, the linearity of the amplifier gain will be determined by the load. Several amplifier topologies provide a mechanism to compensate for changes in the amplifier gain with various loudspeaker loads. One of these methods utilizes feedback. The amplifier output signal following the interior lowpass is input to the amplifier input for comparison. If not created adequately, this technique may cause instability of the amplifier however. A different strategy is to provide dedicated outputs for different speaker impedances that are attached to the amplifier power stage via audio transformers.
A large frequency response does not necessarily mean the amplifier offers good audio quality. For instance an amplifier having a frequency response between 30 Hz and 15 kHz might sound better than a different amplifier having a response between 10 Hz and 30 kHz. Moreover, each maker, it appears, uses a different way of specifying the lowest and highest frequency of their amplifiers. The conventional convention is to show the frequency range within which the amplification will decrease no more than 3 dB from the nominal gain.
Nevertheless, many companies dismiss this particular established practice. They push the lower frequency and upper frequency to where the amplifier barely provides any gain. Moreover, these numbers say very little about how linear the amp is working inside this range. A full frequency response chart, on the other hand, will demonstrate if there are any kind of peaks or valleys and in addition show the way the frequency response is to be understood. Peaks along with valleys may cause colorization of the sound. Ideally the gain of the amplifier should be linear over the entire working range.
This change is most apparent with most digital amps, also known as Class-D amplifiers. Class-D amplifiers employ a lowpass filter in their output to be able to reduce the switching components which are generated through the internal power FETs. Then again, the frequency response of the amplifier now depends on the speaker load because the behavior of this lowpass filter is affected by the load impedance. Generally the lower the loudspeaker load impedance the lower the upper cut-off frequency of the amp
Typically modern digital or "Class-D" amplifiers will show changes in the frequency response with different loads. The primary reason is the fact that Class-D amplifiers employ switching FETs as the power phase that create quite a lot of switching components. These components are eliminated by using a filter which is part of the amplifier. A varying loudspeaker load will impact the filter response to some extent. Commonly the lower the speaker impedance the lower the maximum frequency of the amplifier. Furthermore, the linearity of the amplifier gain will be determined by the load. Several amplifier topologies provide a mechanism to compensate for changes in the amplifier gain with various loudspeaker loads. One of these methods utilizes feedback. The amplifier output signal following the interior lowpass is input to the amplifier input for comparison. If not created adequately, this technique may cause instability of the amplifier however. A different strategy is to provide dedicated outputs for different speaker impedances that are attached to the amplifier power stage via audio transformers.
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