Why Frequency Response of 10Hz - 79kHz
- Thread starter mikewxyz
- Start date
I’ve been corrected. The word is infrasonic not subsonic but you get the idea. My old Classe’ Audio amplifier employed this strategy. I thought part of it was to prevent turntable rumble from being transmitted to the speakers.
If the speakers are the weak link in the distortion chain, does it make sense to NOT ask them to respond to signals outside their capability? Otherwise, seems like the result would only be more distortion.
If the speakers are the weak link in the distortion chain, does it make sense to NOT ask them to respond to signals outside their capability? Otherwise, seems like the result would only be more distortion.
SmartOne_2000
Active member
A pipe organ and classical piano can reach down to 16.4Hz, with custom organ pipes designed to reach 8Hz! Only turntables are designed to mitigate infrasonic rumbles, and many TT preamps include a rumble filter for that purpose.
The amp is supposed to be a straight-wire-with-gain, ranging from DC to infinity, so limiting its frequency range does not fulfill that purpose. Let the loudspeakers be the limiting factor, as they always are, both on the low and high ends of the frequency spectrum.
The amp is supposed to be a straight-wire-with-gain, ranging from DC to infinity, so limiting its frequency range does not fulfill that purpose. Let the loudspeakers be the limiting factor, as they always are, both on the low and high ends of the frequency spectrum.
Hi @mikewxyz
Further to @SmartOne_2000 comments, another reason for the extended response is to ensure that the amplifier behaves in a linear fashion in the frequency band of interest (obstensively 20Hz to 20kHz).
As you approach the frequency range limits, or if you deliberately filter the signal to limit the response range, you can encounter undesirable effects such as phase shift. So it's good practice to have an extended frequency response.
Turntable rumble is a different case. It is essentially a noise signal at such low frequency and high amplitude that it can make woofers hit their end stops (woofer excursion increases with lowering frequency). So it is best filtered out, however in doing so you can also rob the music of its lowest frequency content. Of course this is a non issue with modern digital playback.