Many amplifiers have boost or cut centred on various frequencies chosen easily by setting appropriate capacitor, resistor or inductor values in a filter. I think if presence were only a boost at some frequency, the amp maker would have done exactly that and labelled it accordingly, as is done in any graphic equaliser. I think the presence control is not boosting but instead is narrowing the filter band, i.e increasing the 'Q' of the filter. This in turn does boost at the peak frequency, but the difference of mechanism is important. Whether this was originally done by design, or was a byproduct of some interesting accident during testing of an experimental filter, I don't know, but I do know that a parametric EQ with bandwidth adjustment gets me closest to emulating a 'presence' control. As this is 'original research' I can say it here, but not on the main article. I'm hoping this gets people talking about it here and maybe finding something good for the main page.
86.157.51.246 (talk) 17:17, 19 June 2016 (UTC)Reply