diff --git a/manual/configure_rockbox/images/Q_factor.png b/manual/configure_rockbox/images/Q_factor.png new file mode 100644 index 0000000000..1d5954a1dc Binary files /dev/null and b/manual/configure_rockbox/images/Q_factor.png differ diff --git a/manual/configure_rockbox/sound_settings.tex b/manual/configure_rockbox/sound_settings.tex index 7022315c83..1bfbb2311a 100644 --- a/manual/configure_rockbox/sound_settings.tex +++ b/manual/configure_rockbox/sound_settings.tex @@ -333,13 +333,28 @@ change to customise your listening experience. \opt{swcodec}{ \section{\label{ref:EQ}Equalizer} \screenshot{configure_rockbox/images/ss-equalizer}{The graphical equalizer}{} - Rockbox features a parametric equalizer (EQ). As the name suggests, a - parametric EQ lets you control several different parameters for each - band of the EQ. \nopt{gigabeats}{In some ways the EQ is similar to the + Rockbox features a parametric equalizer (EQ). In contrast to non-parametric + equalizers, a parametric EQ enables adjusting the center frequency, gain, and + width of EQ bands separately. The ability to adjust the frequency and width + of bands enables more precise control of the EQ frequency response while + avoiding the use of a large number of bands (often 12+) needed in a + non-parametric EQ. + + The graphic below illustrates how the width of 10kHz band can be adjusted to + cover a wider (lower Q) or narrower (higher Q) range of frequencies. + + \includegraphics[width=14cm]{configure_rockbox/images/Q_factor.png} + + \nopt{gigabeats}{In some ways the EQ is similar to the \setting{Bass} and \setting{Treble} settings described earlier, but the EQ - allows you to control the sound much more carefully.} \opt{gigabeats}{The EQ - is similar to the \setting{Tone Controls} described above, but allows more - delicate control.}\\ + allows you to control the sound much more carefully. Note that the parameteric + EQ bands will be applied in addition to any bass or treble tone controls. + } \opt{gigabeats}{The EQ is similar to the \setting{Tone Controls} described + above, but allows more delicate control.}\\ + + \note{A maximum of 10 EQ bands are possible on most devices, but using more + than are required will waste battery and introduce additional rounding + noise. For best results, use the fewest number of bands required.} Rockbox's parametric EQ is composed of five different bands: \begin{description} @@ -362,7 +377,7 @@ change to customise your listening experience. centre frequency chosen. Graphic equalizers in home stereos are usually peaking filters. The peaking filters in Rockbox's EQ lets you adjust three - different parameters for EQ bands 1 through 3. The ``centre'' parameter + different parameters for EQ bands 1 through 8. The ``centre'' parameter controls the centre frequency of the frequency range that is affected as described above. The ``gain'' parameter controls how much each band is adjusted, and