Patch #4891 by Michael DiFebbio. Some updates and additions to the Configure Rockbox chapter.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@9195 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 23 insertions, 7 deletions

diff --git a/manual/configure_rockbox/main.tex b/manual/configure_rockbox/main.tex
index d674a5bd21..72dede7ed7 100644
--- a/manual/configure_rockbox/main.tex
+++ b/manual/configure_rockbox/main.tex
@@ -9,20 +9,27 @@ This menu offers a selection of sound properties you may change to improve your
 
 \begin{itemize}
 \item \textbf{Volume}
-  The sound volume your music is played at.
-  \opt{recorder,recorderv2fm,player,ondio}{
-    Although settable range is 0{}-100\%, many units don't produce audible output below 40\%.  On Recorders, volume settings above 92\% will cause distortion (clipping) and are not recommended.}
-  \opt{h1xx,h300,ipodcolor,ipodnano,ipodvideo}{TODO Write target specific text}
+  This control adjusts the volume of your music.  Like most professional audio gear and many consumer audio products, Rockbox uses a decibel scale where 0 dB is a reference that indicates the maximum volume that the \dap can produce without distortion (clipping).  Because the volume control is basically a comparison of the volume level you set to a reference volume of 0 dB.
+  \opt{player}{  Volume can be adjusted from a minimum of -78 dB to a maximum of +18 dB.}
+  \opt{recorder,recorderv2fm,ondio}{  Volume can be adjusted from a minimum of -100 dB to a maximum of +12 dB.}
+  \opt{h1xx,h300}{  Volume can be adjusted from a minimum of -84 dB to a maximum of 0 dB.}
+  \opt{ipodnano}{  Volume can be adjusted from a minimum of -72 dB to a maximum of +6 dB.}
+  \opt{ipodvideo}{  Volume can be adjusted from a minimum of -57 dB to a maximum of +6 dB.}
+  \opt{ipodcolor}{  Volume can be adjusted from a minimum of -?? dB to a maximum of +?? dB.}
 \item \textbf{Bass}
-  This emphasises or suppresses the lower (bass) sounds in the track.  0 means that bass sounds are unaltered (flat response).
+  \opt{player,recorder,recorderv2fm,ondio}{This emphasises or suppresses the lower (bass) sounds in the track.  0 means that bass sounds are unaltered (flat response).}
+  \opt{h1xx,h300}{The Bass setting can be used to increase (but not decrease) frequencies below 300Hz. Bass boost can be set from 0 to 24 dB in increments of 2 dB. A setting of 0 means that low frequencies are unaltered (flat response).}
+  \opt{ipodnano,ipodcolor,ipodvideo}{TODO - platform specific description.}
 \item \textbf{Treble}
-  This emphasises or suppresses the higher (treble) sounds in the track.  0 means that treble sounds are unaltered (flat response).
+  \opt{player,recorder,recorderv2fm,ondio}{This emphasises or suppresses the higher (treble) sounds in the track.  0 means that treble sounds are unaltered (flat response).}
+  \opt{h1xx,h300}{The Treble setting can be used to increase (but not decrease) frequencies above 1.5kHz. Treble boost can be set from 0 to 6 dB in increments of 2 dB. A setting of 0 means that high frequencies are unaltered (flat response).}
+  \opt{ipodnano,ipodcolor,ipodvideo}{TODO - platform specific description.}
 \item \textbf{Balance}
   How much of the volume is generated by the left or right channel of the sound.  The default, 0, means that the left and right outputs are equal in volume.  Negative numbers increase the volume of the left channel relative to the right, positive numbers increase the volume of the right channel relative to the left.
 \item \textbf{Channels}
   
   \opt{player,recorder,recorderv2fm,ondio}{
-    This option controls the on{}-board mixing facilities of the Jukebox.  A stereo audio signal consists of two channels, left and right.  Available options are
+    This option controls the on{}-board mixing facilities of the \dap.  A stereo audio signal consists of two channels, left and right.  Available options are
     \begin{itemize}
     \item \textbf{Mono Left: }Plays the left channel in both stereo channels.
     \item \textbf{Mono Right:} Plays the right channel in both stereo channels.
@@ -222,6 +229,15 @@ This menu deals with options relating to how the file browser displays files
     \end{itemize}
   }
 
+  
+  \opt{SWCODEC}{
+  \item \textbf{Crossfeed}
+
+    Crossfeed attempts to make the experience of listening to music on headphones more similar to listening to stereo speakers. When you listen to music through speakers, your right ear hears sound from the left speaker and vice versa. However, the sound from the left speaker reaches your left ear slightly later than the sound from your right ear, and vice versa. Moreover, when listening to speakers, you hear the direct sound from the speakers, but you also hear reflections of that sound as the sound waves bounce off of walls, floors, ceilings, etc. These reflections reach your ears slightly after the direct sound. The human ear and brain are very good at interpreting the timing differences between direct sounds and reflected sounds and using that information to identify the direction that the sound is coming from.  On the other hand, when listening to headphones, your ear hears only the direct sounds, and not reflections. Moreover, your left ear hears only the left channel and the right ear hears only the right channel. The result is that sound from headphones does not provide the same spatial cues to your ear and brain as speakers.
+    
+    The crossfeed function uses an algorithm to feed a delayed and filtered portion of the signal from the right channel into the left channel and vice versa in order to simulate the spatial cues that the ear and brain receive when listening to non-headphone sources. The result is a better stereo image.
+  }
+
   \opt{recorder,recorderv2fm,ondio,h1xx,h300,ipodnano,ipodcolor,ipodvideo}{
   \item \textbf{Peak Meter}
     The peak meter can be configured with a number of parameters.  (For a description of the peak meter see page \pageref{ref:Peakmeter}.)