Tone control circuits
Between the source of the sound
signal and the
loudspeaker(s) all sorts of changes to that
signal can be made by various
tone control circuits. They may be just very simple, or very elaborate, as required by users, and these
circuits are often called
filters.
* Basically, sound (audio)
signals are alternating voltages/currents, and therefore the reactances of
capacitors and of
inductances depend on the
frequencies (
tones) that are a part of the signal. Capacitors "let through" more of the higher tones, while inductors reduce their
amplitude. Often there is also use made, more or less, of the
resonance at a particular tone, when the reactance of a capacitor at a particular frequency (tone) equals the reactance of an inductance (coil).
* Some people prefer an attenuation (reduction) of the "strength" (amplitude) of the higher tones, while many older people, who may have a hearing problem, prefer an emphasis of the higher tones.
* A simple
RC circuit (one
capacitor and one
resistor) could reduce or increase, depending on how they are connected, the tone at the rate of 20
decibels per
decade, which is equivalent to 6 decibels per
octave.
*
Audio amplifier*
Electronic filter*
Audio crossover* [
1]
* [
2]
* [
3]
*
Negative-Feedback Tone Control â€" Independent Variation of Bass and Treble Without Switches By P. J. Baxandall
* [
4]
