| % $Id$ % |
| \screenshot{configure_rockbox/images/ss-sound-settings}{The sound settings screen}{} |
| |
| The sound settings menu offers a selection of sound settings you may |
| change to customise your listening experience. |
| |
| \section{\label{ref:volume}Volume} |
| This setting 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 possible distortion (clipping). All values lower than |
| this reference will be negative and yield a progressively softer volume. |
| \nopt{iriverh100,iriverh300,ondavx777}{% |
| Values higher than 0~dB are available and can be used to raise the |
| volume more than would otherwise be possible. These volume levels will |
| ordinarily lead to distorted sound, but might work nicely for music that has |
| an otherwise low volume level. |
| } |
| The volume can be adjusted from a |
| \opt{player}{minimum of -78~dB to a maximum of +18~dB.}% |
| \opt{recorder,recorderv2fm,ondio}{minimum of -100~dB to a maximum of +12~dB.}% |
| \opt{iriverh100,iriverh300}{minimum of -84~dB to a maximum of 0~dB.}% |
| \opt{iaudiom3,iaudiom5,iaudiox5,ipod3g,ipod4g,gigabeatf,mrobe100,mpiohd200}{% |
| minimum of -73~dB to a maximum of +6~dB.}% |
| \opt{ipodnano}{minimum of -72~dB to a maximum of +6~dB.}% |
| \opt{ipodvideo,cowond2}{minimum of -89~dB to a maximum of +6~dB.}% |
| \opt{ipodnano2g,ipodcolor,ipod1g2g,iriverh10,iriverh10_5gb,sansa,sansaAMS}{minimum of |
| -74~dB to a maximum of +6~dB.}% |
| \opt{gigabeats}{minimum of -90~dB to a maximum of +6~dB.}% |
| \opt{gigabeatf,vibe500}{minimum of -74~dB to a maximum of +6~dB.}% |
| \opt{fuzeplus}{minimum of -100~dB to a maximum of +6~dB.} |
| \opt{ipodvideo}{\\Remark: Lowering the volume below -57~dB will also affect the line-out |
| and the recording gain.} |
| \opt{cowond2}{\\Remark: Lowering the volume below -57~dB will also affect the line-out.} |
| |
| \nopt{gigabeats}{ |
| \section{Bass} |
| This setting emphasises |
| \nopt{iriverh100,iriverh300}{or suppresses} |
| the lower (bass) frequencies in the sound. A value of 0~dB means that bass |
| sounds are unaltered (flat response). |
| \opt{masd}{The minimum setting is -15~dB and the maximum is 15~dB.}% |
| \opt{masf}{The minimum setting is -12~dB and the maximum is 12~dB.}% |
| \opt{iriverh100,iriverh300}{The minimum setting is 0~dB and the maximum is 24~dB.}% |
| \opt{ipodnano,ipodnano2g,ipodcolor,mpiohd200}{% |
| The minimum setting is -6~dB and the maximum is 9~dB.}% |
| \opt{ipodvideo}{The minimum setting is -12~dB and the maximum is 12~dB.}% |
| \opt{iaudiom3,iaudiom5,iaudiox5,sansa,sansaAMS,iriverh10,iriverh10_5gb,vibe500,fuzeplus}{% |
| The minimum setting is -24~dB and the maximum is 24~dB.} |
| |
| \opt{ipodvideo}{ |
| \section{Bass Cutoff} |
| This setting controls the frequency below which the bass adjustment applies. |
| The setting has a range from 1 to 4, where a bigger number affects a bigger |
| range of bass frequencies. The actual cutoff frequency used for each setting |
| value will vary with sample rate. |
| } |
| |
| \section{Treble} |
| This setting emphasises |
| \nopt{iriverh100,iriverh300}{or suppresses} |
| the higher (treble) frequencies in the sound. A value of 0~dB means that |
| treble sounds are unaltered (flat response). |
| \opt{masd}{The minimum setting is -15~dB and the maximum is 15~dB.}% |
| \opt{masf}{The minimum setting is -12~dB and the maximum is 12~dB.}% |
| \opt{iriverh100,iriverh300}{The minimum setting is 0~dB and the maximum is 6~dB.}% |
| \opt{ipodnano,ipodnano2g,ipodcolor,mpiohd200}{% |
| The minimum setting is -6~dB and the maximum is 9~dB.}% |
| \opt{ipodvideo}{The minimum setting is -12~dB and the maximum is 12~dB.}% |
| \opt{iaudiom3,iaudiom5,iaudiox5,sansa,sansaAMS,iriverh10,iriverh10_5gb,vibe500,fuzeplus}{% |
| The minimum setting is -24~dB and the maximum is 24~dB.} |
| |
| \opt{ipodvideo}{ |
| \section{Treble Cutoff} |
| This setting controls the frequency above which the treble adjustment applies. |
| The setting has a range from 1 to 4, where a bigger number affects a smaller |
| range of treble frequencies. The actual cutoff frequency used for each setting |
| value will vary with sample rate. |
| } |
| } |
| |
| \opt{gigabeats}{ |
| \section{Tone Controls} |
| There is a five-band equalizer built into your \dap{} that allows you to |
| control various different parameters for each band. This equalizer is |
| implemented in hardware, and therefore does not tax the processor when in use. |
| Rockbox also features a more advanced five-band equalizer (see |
| \reference{ref:EQ}) that is implemented in software and allows more fine |
| grained control, but also requires more processor time. |
| |
| \begin{description} |
| \item[Band 1 Gain.] |
| This band acts as a low shelf filter that boosts or lowers all |
| frequencies below a certain frequency limit, much as a ``bass'' |
| control found on ordinary stereo systems does. The ``gain'' parameter |
| controls how much the loudness of the band is adjusted. Positive |
| numbers make the EQ band louder, while negative numbers make that EQ |
| band quieter. |
| \item[Bands 2-4 Gain.] |
| These bands act as peaking filters that boost or lower a frequency |
| range centered at a certain frequency. Graphic equalizers in home |
| stereos are usually peaking filters. The ``gain'' parameter controls |
| how much each band is adjusted as with the the low shelf filter. |
| \item[Band 5 Gain.] |
| Band 5 acts as a high shelf filter, boosting or lowering all |
| frequencies above a certain frequency limit, much like a ``treble'' |
| control found on ordinary stereo systems does. As with the other bands, |
| ``gain'' controls how much each band is adjusted. |
| \item[Advanced Tone Control Settings.] |
| This submenu allows you to change advanced parameters for each band. |
| \end{description} |
| |
| As a general guide, EQ band 1 should be used for low frequencies, EQ bands 2 |
| to 4 should be used for mids, and EQ band 5 should be used for highs.\\* |
| |
| \subsection{Advanced Tone Control Settings} |
| As in the previous menu, the ``gain'' setting controls how much the |
| loudness of the band is adjusted. In addition the following parameters |
| can be adjusted: |
| |
| \begin{description} |
| \item[Band 1 Frequency.] |
| The ``frequency'' parameter sets where the shelving starts to take |
| effect. For example, a cutoff frequency of 80~Hz will adjust only very |
| low frequencies. A cutoff frequency of 175~Hz, on the other hand, will |
| adjust a much wider range of bass frequencies. |
| \item[Bands 2-4 Frequency.] |
| The ``frequency'' parameter for these bands sets the centre frequency of |
| the range that is affected by the gain set. |
| \item[Bands 2-4 Width.] |
| This parameter sets the width of the range around the centre frequency |
| that is affected by the tone control. The possible settings are |
| ``wide'' or ``narrow''. |
| \item[Band 5 Frequency.] |
| This works just as for band 1 frequency, except that it affects the |
| high frequency end of the spectrum instead of the low. |
| \end{description} |
| |
| } |
| |
| \section{Balance} |
| This setting controls the balance between the left and right channels. 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. |
| |
| \section{Channels} |
| A stereo audio signal consists of two channels, left and right. The |
| \setting{Channels} setting determines if these channels are to be combined in |
| any way, and if so, in what manner they will be combined. |
| Available options are: |
| % |
| \begin{description} |
| \item[Stereo.] |
| Leave the audio signal unmodified. |
| \item[Mono.] |
| Combine both channels and send the resulting signal to both stereo |
| channels, resulting in a monophonic output. |
| \item[Custom.] |
| Allows you to manually specify a stereo width with the |
| \setting{Stereo Width} setting described later in this chapter. |
| \item[Mono Left.] |
| Plays the left channel in both stereo channels. |
| \item[Mono Right.] |
| Plays the right channel in both stereo channels. |
| \item[Karaoke.] |
| Removes all sound that is common to both channels. Since most |
| music is recorded with vocals being equally present in both channels |
| to make the singer sound centrally placed, this often (but not |
| always) has the effect of removing the voice track from a song. This |
| setting also very often has other undesirable effects on the sound. |
| \end{description} |
| |
| \section{Stereo Width} |
| Stereo width allows you to manually specify the effect that is applied |
| when the \setting{Channels} setting is set to ``custom''. |
| All values below 100\% will progressively mix the contents of one channel |
| into the other. This has the effect of gradually centering the stereo image, |
| until you have monophonic sound at 0\%. Values above 100\% will progressively |
| remove components in one channel that is also present in the other. This has |
| the effect of widening the stereo field. A value of 100\% will leave the |
| stereo field unaltered. |
| |
| \opt{masf}{ |
| \section{Loudness} |
| When listening at low volumes, the ear will tend to make bass and treble |
| frequencies sound quieter than they really are. To compensate for this, |
| \setting{Loudness} is an effect which emphasises bass and treble in a fashion |
| suited to the human ear. Frequencies in the vocal range are unaffected, since |
| the human ear picks these up very easily at any sound level. |
| It is of course also possible to use this effect at higher volumes for |
| enhanced bass and treble. |
| } |
| |
| \opt{masf}{ |
| \section{Auto Volume} |
| Auto volume is a feature that automatically lowers the volume on loud parts, |
| and then slowly restores the volume to the previous level over a time |
| interval. This setting allows this time interval to be configured. Short |
| values like 20~ms are useful for ensuring a constant volume for in-car use and |
| other applications where background noise makes a constant loudness desirable. |
| A longer timeout means that the change in volume back to the previous level |
| will be smoother, so there will be fewer sharp changes in volume level. |
| } |
| |
| \opt{masf}{ |
| \section{Super Bass} |
| This setting changes the threshold at which bass frequencies are affected by |
| the \setting{Loudness} setting, making the sound of drums and bass guitar |
| louder in comparison to the rest of the sound. This setting only has an |
| effect if \setting{Loudness} is set to a value larger than 0~dB. |
| } |
| |
| \opt{masf}{ |
| \section{MDB {}-- Micronas Dynamic Bass} |
| The rest of the parameters in this menu relate to the Micronas Dynamic |
| Bass (MDB) function. MDB is designed to enable the user to hear bass |
| notes that the headphones and/or speakers are not capable of reproducing. |
| Every tone has a fundamental frequency (the ``main tone'') and also several |
| harmonics, which are related to that tone. The human brain has a mechanism |
| whereby it can actually infer the presence of bass notes from the higher |
| harmonics that they would generate. |
| |
| The practical upshot of this is that MDB produces a more authentic sounding |
| bass by tricking the brain into believing it is hearing tones that the |
| headphones or speakers are not capable of reproducing. |
| |
| The MDB parameters are as follows: |
| % |
| \begin{description} |
| \item[MDB enable.] |
| This turns the MDB feature on or off. For many users this will be the |
| only setting they need, since Rockbox picks sensible defaults for the |
| other parameters. MDB is turned off by default. |
| \item[MDB strength.] |
| How loud the harmonics generated by MDB will be. |
| \item[MDB Harmonics.] |
| The percentage of the low notes that is converted into harmonics. |
| If low notes are causing speaker distortion, this can be set to 100\% |
| to eliminate the fundamental completely and only produce harmonics in the |
| signal. If set to 0\% this is the same as turning the MDB feature off. |
| \item[MDB Centre Frequency.] |
| The cutoff frequency of your headphones or speakers. This is usually |
| given in the specification for the headphones/speakers. |
| \item[MDB shape.] |
| It is recommended that this parameter be set to 1.5 times the centre frequency. |
| |
| This is the frequency up to which harmonics are generated. Some of the |
| lower fundamentals near the cut{}-off range will have their lower |
| harmonics cut, since they will be below the range of the speakers. |
| Fundamentals between the cut{}-off frequency and the lower frequency |
| will have their harmonics proportionally boosted to compensate and restore |
| the `loudness' of these notes. |
| |
| For most users, the defaults should provide an improvement in sound |
| quality and can be safely left as they are. For reference, the defaults |
| Rockbox uses are: |
| % |
| \begin{table}[h!] |
| \begin{rbtabular}{0.5\textwidth}{Xc}{Setting & Value}{}{} |
| MDB Strength & 50~dB \\ |
| MDB Harmonics & 48\% \\ |
| MDB Centre Frequency & 60~Hz \\ |
| MDB Shape & 90~Hz \\ |
| \end{rbtabular} |
| \end{table} |
| |
| \end{description} |
| } |
| |
| \opt{swcodec}{ |
| \section{Crossfeed} |
| Crossfeed attempts to make the experience of listening to music on |
| headphones more similar to listening to music with stereo speakers. When you |
| listen to music through speakers, each ear will hear sound originating from |
| both speakers. However, the sound from the left speaker reaches your right |
| ear slightly later than it does your left ear, and vice versa.\\ |
| |
| The human ear and brain together are very good at interpreting the time |
| 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, each ear hears only the stereo |
| channel corresponding to it. The 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, and might for that reason sound unnatural to some listeners.\\ |
| |
| 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 a set of loudspeakers placed in front of the listener. The |
| result is a more natural stereo image that can be especially appreciated in |
| older rock and jazz records, where one instrument is often hard-panned to |
| just one of the speakers. Many people will find such records tiring to listen |
| to using earphones and no crossfeed effect.\\ |
| |
| Crossfeed has the following settings: |
| \begin{description} |
| \item[Crossfeed.] |
| Selects whether the crossfeed effect is to be enabled or not. |
| \item[Direct Gain.] |
| How much the level of the audio that travels the direct path from a speaker |
| to the corresponding ear is supposed to be decreased. |
| \item[Cross Gain.] |
| How much the level of the audio that travels the cross path from a speaker |
| to the opposite ear is to be decreased. |
| \item[High-Frequency Attenuation.] |
| How much the upper frequencies of the cross path audio will be dampened. |
| Note that the total level of the higher frequencies will be a combination |
| of both this setting and the \setting{Cross Gain} setting. |
| \item[High-Frequency Cutoff.] |
| Decides at which frequency the cross path audio will start to be cut |
| by the amount described by the \setting{High-Frequency Attenuation} |
| setting. |
| \end{description} |
| |
| Most users will find the default settings to yield satisfactory results, but |
| for the more adventurous user the settings can be fine-tuned to provide a |
| virtual speaker placement suited to ones preference. |
| % TODO: adapt the guidelines for crossfeed settings found here? |
| % http://www.ohl.to/interests-in-audio/crossfeed-and-eq-for-headphones/ |
| Beware that the crossfeed function is capable of making the audio distort |
| if you choose settings which result in a too high output level. |
| } |
| |
| \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 |
| \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.}\\ |
| |
| Rockbox's parametric EQ is composed of five different bands: |
| \begin{description} |
| \item[Band 0: Low shelf filter.] |
| The low shelf filter boosts or lowers all frequencies below a certain |
| frequency limit, much as the ``bass'' control found on ordinary |
| stereo systems does. |
| Adjust the ``cutoff'' frequency parameter to decide where the shelving |
| starts to take effect. For example, a cutoff frequency of 50~Hz will |
| adjust only very low frequencies. A cutoff frequency of 200~Hz, on the |
| other hand, will adjust a much wider range of bass frequencies. |
| The ``gain'' parameter controls how much the loudness of the band is |
| adjusted. Positive numbers make the EQ band louder, while negative |
| numbers make that EQ band quieter. |
| The ``Q'' parameter should always be set to 0.7 for the shelving |
| filters. Higher values will add a small boost around the cutoff |
| frequency that is almost always undesirable. |
| \item[Bands 1-8: Peaking filters.] |
| Peaking EQ filters boost or lower a frequency range centered at the |
| 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 |
| 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 |
| works as for the low shelf filter. |
| Finally, the ``Q'' parameter controls how wide or narrow the affected |
| frequency range is. Higher Q values will affect a narrower band of |
| frequencies, while lower Q values will affect a wider band of |
| frequencies. |
| \item[Band 9: High shelf filter.] |
| A high shelf filter boosts or lowers all frequencies above a certain |
| frequency limit, much as the ``treble'' control found on ordinary |
| stereo systems does. |
| The high shelf filter is adjusted the same way as the low shelf filter, |
| except that it works on the high end of the frequency spectrum rather |
| than the low end. |
| \end{description} |
| As a general guide, EQ band 0 should be used for low frequencies, EQ bands 1 |
| through 8 should be used for mids, and EQ band 9 should be used for highs. |
| |
| \begin {description} |
| \item[Enable EQ.] |
| This option controls whether the EQ is on or off. |
| |
| \item[Graphical EQ.] |
| This option brings up a graphic EQ screen, which allows adjustment of each of |
| the three parameters described above (gain, centre frequency, and Q) for each |
| of the five EQ bands. |
| |
| \begin{btnmap} |
| \opt{IRIVER_H100_PAD,IRIVER_H300_PAD,IAUDIO_X5_PAD,GIGABEAT_PAD% |
| ,GIGABEAT_S_PAD,SANSA_C200_PAD,IAUDIO_M3_PAD,MROBE100_PAD% |
| ,SANSA_CLIP_PAD,SANSA_FUZEPLUS_PAD}{\ButtonRight} |
| \opt{SANSA_E200_PAD,SANSA_FUZE_PAD,IPOD_4G_PAD,IPOD_3G_PAD}{\ButtonScrollFwd} |
| \opt{IRIVER_H10_PAD}{\ButtonScrollUp} |
| \opt{PBELL_VIBE500_PAD}{\ButtonUp} |
| \opt{MPIO_HD200_PAD}{\ButtonVolUp} |
| \opt{MPIO_HD300_PAD}{\ButtonScrollUp} |
| \opt{touchscreen}{\TouchMidRight} |
| & |
| \opt{HAVEREMOTEKEYMAP}{ |
| \opt{GIGABEAT_RC_PAD}{\ButtonRCFF} |
| \opt{IAUDIO_RC_PAD}{\ButtonRCRight} |
| &} |
| Raises the highlighted parameter. |
| \\ |
| % |
| \opt{IRIVER_H100_PAD,IRIVER_H300_PAD,IAUDIO_X5_PAD,GIGABEAT_PAD% |
| ,GIGABEAT_S_PAD,SANSA_C200_PAD,IAUDIO_M3_PAD,MROBE100_PAD% |
| ,SANSA_CLIP_PAD,SANSA_FUZEPLUS_PAD}{\ButtonLeft} |
| \opt{SANSA_E200_PAD,SANSA_FUZE_PAD,IPOD_4G_PAD,IPOD_3G_PAD}{\ButtonScrollBack} |
| \opt{IRIVER_H10_PAD}{\ButtonScrollDown} |
| \opt{PBELL_VIBE500_PAD}{\ButtonDown} |
| \opt{MPIO_HD200_PAD}{\ButtonVolDown} |
| \opt{MPIO_HD300_PAD}{\ButtonScrollDown} |
| \opt{touchscreen}{\TouchMidLeft} |
| & |
| \opt{HAVEREMOTEKEYMAP}{ |
| \opt{GIGABEAT_RC_PAD}{\ButtonRCRew} |
| \opt{IAUDIO_RC_PAD}{\ButtonRCLeft} |
| &} |
| Lowers the highlighted parameter. |
| \\ |
| % |
| \opt{IPOD_4G_PAD,IPOD_3G_PAD,PBELL_VIBE500_PAD}{\ButtonLeft} |
| \opt{IRIVER_H100_PAD,IRIVER_H300_PAD,IAUDIO_X5_PAD,SANSA_E200_PAD,SANSA_C200_PAD% |
| ,SANSA_FUZE_PAD,GIGABEAT_PAD,GIGABEAT_S_PAD,IAUDIO_M3_PAD,MROBE100_PAD% |
| ,SANSA_CLIP_PAD,SANSA_FUZEPLUS_PAD}{\ButtonUp} |
| \opt{IRIVER_H10_PAD,MPIO_HD200_PAD,MPIO_HD300_PAD}{\ButtonRew} |
| \opt{touchscreen}{\ActionStdPrev} |
| & |
| \opt{HAVEREMOTEKEYMAP}{ |
| \opt{IRIVER_RC_H100_PAD}{\ButtonRCRew} |
| \opt{GIGABEAT_RC_PAD}{\ButtonRCVolUp} |
| \opt{IAUDIO_RC_PAD}{\ButtonRCUp} |
| &} |
| Moves to the previous EQ band. |
| \\ |
| % |
| \opt{IPOD_4G_PAD,IPOD_3G_PAD,PBELL_VIBE500_PAD}{\ButtonRight} |
| \opt{IRIVER_H100_PAD,IRIVER_H300_PAD,IAUDIO_X5_PAD,SANSA_E200_PAD,SANSA_C200_PAD% |
| ,SANSA_FUZE_PAD,GIGABEAT_PAD,GIGABEAT_S_PAD,IAUDIO_M3_PAD,MROBE100_PAD% |
| ,SANSA_CLIP_PAD,SANSA_FUZEPLUS_PAD}{\ButtonDown} |
| \opt{IRIVER_H10_PAD,MPIO_HD200_PAD,MPIO_HD300_PAD}{\ButtonFF} |
| \opt{touchscreen}{\ActionStdNext} |
| & |
| \opt{HAVEREMOTEKEYMAP}{ |
| \opt{IRIVER_RC_H100_PAD}{\ButtonRCFF} |
| \opt{GIGABEAT_RC_PAD}{\ButtonRCVolDown} |
| \opt{IAUDIO_RC_PAD}{\ButtonRCDown} |
| &} |
| Moves to the next EQ band. |
| \\ |
| % |
| \opt{IRIVER_H100_PAD,IRIVER_H300_PAD,GIGABEAT_PAD,GIGABEAT_S_PAD,IAUDIO_X5_PAD% |
| ,SANSA_C200_PAD,IPOD_4G_PAD,IPOD_3G_PAD,IPOD_VIDEO_PAD,SANSA_E200_PAD% |
| ,SANSA_FUZE_PAD,MROBE100_PAD,SANSA_CLIP_PAD,SANSA_FUZEPLUS_PAD}{\ButtonSelect} |
| \opt{MPIO_HD200_PAD}{\ButtonFunc} |
| \opt{MPIO_HD300_PAD}{\ButtonEnter} |
| \opt{PBELL_VIBE500_PAD}{\ButtonOK} |
| \opt{IRIVER_H10_PAD}{\ButtonRight} |
| \opt{IAUDIO_M3_PAD}{\ButtonPlay} |
| \opt{touchscreen}{\TouchCenter |
| \opt{COWON_D2_PAD}{/ \ButtonMenu}} |
| & |
| \opt{HAVEREMOTEKEYMAP}{ |
| \opt{IRIVER_RC_H100_PAD}{\ButtonRCSelect} |
| \opt{GIGABEAT_RC_PAD,IAUDIO_RC_PAD}{\ButtonRCPlay} |
| &} |
| Toggles the cursor among the three parameters (gain, centre frequency, |
| Q) for the selected EQ band |
| \\ |
| % |
| \opt{IRIVER_H100_PAD,IRIVER_H300_PAD}{\ButtonMode} |
| \opt{IPOD_4G_PAD,IPOD_3G_PAD,MPIO_HD300_PAD}{\ButtonMenu} |
| \opt{IAUDIO_X5_PAD}{\ButtonPower/\ButtonRec} |
| \opt{IAUDIO_M3_PAD,MPIO_HD200_PAD}{\ButtonRec} |
| \opt{SANSA_E200_PAD,SANSA_FUZE_PAD,IRIVER_H10_PAD}{\ButtonLeft} |
| \opt{GIGABEAT_PAD,GIGABEAT_S_PAD,SANSA_C200_PAD,MROBE100_PAD,SANSA_CLIP_PAD}{\ButtonPower} |
| \opt{PBELL_VIBE500_PAD}{\ButtonCancel} |
| \opt{SANSA_FUZEPLUS_PAD}{\ButtonBack} |
| \opt{touchscreen}{\TouchTopLeft |
| \opt{COWON_D2_PAD}{/ \ButtonPower}} |
| & |
| \opt{HAVEREMOTEKEYMAP}{ |
| \opt{IRIVER_RC_H100_PAD}{\ButtonRCStop} |
| \opt{GIGABEAT_RC_PAD}{\ButtonRCDsp} |
| \opt{IAUDIO_RC_PAD}{\ButtonRCRec} |
| &} |
| Exits the graphic EQ screen. |
| \\ |
| \end{btnmap} |
| |
| \item[Pre-cut.] |
| If too much positive gain is added through the graphical EQ, your music may |
| distort. The \setting{Precut} setting allows you to apply a global negative |
| gain to decoded audio, cancelling out positive gain from the EQ. This will |
| prevent distortion when boosting certain frequency ranges, at the expense of |
| making audio quieter. |
| |
| Alternatively, precut can be used with a flat EQ curve to implement a volume |
| cap. For example, on a player that allows overdriving the headphone output |
| to +6dB, maximum volume can be capped to +0dB by applying 6dB of precut. Note |
| that precut is not applied if EQ is disabled. |
| |
| \item[Simple EQ.] |
| This option provides an easier alternative for those who are daunted by all of |
| the parameters that can be adjusted using the graphical EQ. With the |
| \setting{Simple EQ}, the only parameter that can be adjusted is the gain. |
| |
| \item[Advanced EQ.] |
| This sub menu provides options for adjusting the same parameters as the |
| \setting{Graphical EQ}. The only difference is that the parameters are |
| adjusted through textual menus rather than through a graphic interface. |
| |
| \item[Save EQ Preset.] |
| This option saves the current EQ configuration in a \fname{.cfg} file. |
| |
| \item[Browse EQ Presets.] |
| This menu displays a list of EQ presets, as well as any EQ configurations saved |
| using the \setting{Save EQ Preset} option. Users unfamiliar with the |
| operation of a parametric EQ may wish to use the presets instead of trying to |
| configure the EQ, or use the presets for designing their own custom EQ |
| settings. |
| |
| \end{description} |
| } |
| |
| \opt{swcodec}{ |
| \section{Dithering} |
| This setting controls the dithering and noise shaping functionality of Rockbox. |
| |
| Most of Rockbox' audio file decoders work at a higher bit depth than the 16 bits |
| used for output on the \daps{} audio connectors. The simplest way to |
| convert from one bit depth to another is simply discarding all the surplus bits. |
| This is the default behaviour, and adds distortion to the signal that will |
| vary in character along with the desired sound. |
| |
| Dithering adds low-level noise to the signal prior to throwing away the surplus |
| bits, which gives the resulting signal a uniform noise floor which is |
| independent of the signal. Most people find this noise preferable to the |
| time-varying noise heard when not performing dithering. |
| |
| After dithering, noise shaping is performed. This basically just pushes the |
| dithering noise to the parts of the frequency spectrum humans cannot hear so |
| easily. In Rockbox' case, some of the noise is pushed up to above 10~kHz. |
| |
| This setting will be put to its best use when listening to dynamic music with |
| frequently occuring quiet parts, classical music being a typical example. It is |
| worth noting that the effects of dithering and noise shaping are very subtle, |
| and not easily noticable. |
| |
| Rockbox uses highpass triangular distribution noise as the dithering noise |
| source, and a third order noise shaper. |
| } |
| |
| \opt{swcodec}{% |
| \opt{pitchscreen}{% |
| \section{Timestretch} |
| Enabling \setting{Timestretch} allows you to change the playback speed without |
| it affecting the pitch of the recording. After enabling this feature and |
| rebooting, you can access this via the \setting{Pitch Screen}. This function is |
| intended for speech playback and may significantly dilute your listening |
| experience with more complex audio. See \reference{sec:pitchscreen} for more |
| details about how to use the feature. |
| } |
| } |
| |
| \opt{swcodec}{ |
| \section{Compressor} |
| The \setting{Compressor} reduces, or compresses, the dynamic range of the audio |
| signal. This makes the quieter and louder sections closer to the same volume |
| level by progressively reducing the gain of louder signals. When subsequently |
| amplified, this has the effect of making the quieter sections louder while |
| keeping the louder sections from clipping. This allows listening to the quiet |
| sections of dynamic material in noisy environments while preventing sudden loud |
| sections from being overbearing. |
| |
| There are several settings associated with the compressor. The first, and most |
| important, is the \setting{Threshold}. The threshold is the audio input level |
| at which the compressor begins to act. Any level louder than the threshold |
| will be compressed to some extent. The maximum amount of compression, or the |
| quietest level at which the compressor will operate, is -24~dB. The default of |
| Off disables the compressor. |
| |
| The \setting{Makeup Gain} setting has two options: Off and Auto. Off means |
| that the compressed audio will not be amplified after compression. The default |
| of Auto will amplify the signal so that the loudest possible signal after |
| compression will be just under the clipping limit. This is desirable because |
| the compressed signal without makeup gain is quieter than the input signal. |
| Makeup Gain in Auto restores the signal to the maximum possible level and |
| brings the quieter audio up with it. This is what makes it possible to hear |
| the quieter audio in noisy environments. |
| |
| The \setting{Ratio} setting determines how aggressively the compressor reduces |
| gain above the threshold. For example, the 2:1 setting means that for each |
| two decibels of input signal above the threshold, the compressor will only |
| allow the output to appear as one decibel. The higher the ratio, the harder |
| the signal is compressed. The ratio setting of Limit means essentially a ratio |
| of infinity to one. In this case, the output signal is not allowed to exceed |
| the threshold at all. |
| |
| The \setting{Knee} setting determines how abrupt the transition is from a |
| non-compressed signal to a compressed signal. Hard Knee means that the |
| transition occurs precisely at the threshold. The Soft Knee setting smoothes |
| the transition from plus or minus three decibels around the threshold. |
| |
| The \setting{Release Time} setting sets the recovery time after the signal is |
| compressed. Once the compressor determines that compression is necessary, |
| the input signal is reduced appropriately, but the gain isn't allowed to |
| immediately return to normal levels. This is necessary to reduce artifacts |
| such as ``pumping.'' Instead, the gain is allowed to return to normal at the |
| chosen rate. Release Time is the time for the gain to recover by 10~dB. |
| } |