Rockbox Technical Forums

Rockbox Development => Feature Ideas => Topic started by: peter_s_d on July 04, 2008, 10:44:49 AM

Title: more volume
Post by: peter_s_d on July 04, 2008, 10:44:49 AM
Could the maximum volume be increased by a few dB?  . 

I realise that we do not want to deafen users, but I find that some tracks are too quiet for me against moderate background noise.  If it is relevant I am using a Sansa E200. 

Would it be possible to detect loud tracks and/or peak volume so that the stupid would be protected from themselves?    Allowing a maximum volume of say +10dB with an over volume protection could be an improvement. 
Title: Re: more volume
Post by: saratoga on July 04, 2008, 10:46:53 AM
Volume is determined by the hardware.

Also, gain above 0dB introduce distortion.  If the target actually supported +10dB, its unlikely you'd like what you heard at that volume.  Get more sensitive headphones, an amplifier, or a louder mp3 player if you need more volume.
Title: Re: more volume
Post by: GodEater on July 04, 2008, 11:03:22 AM
Or invest in replaygain on your quiet tracks.
Title: Re: more volume
Post by: terrence1019 on July 04, 2008, 08:47:06 PM
Volume is determined by the hardware.

Also, gain above 0dB introduce distortion. 

Not to mention hearing loss
Title: Re: more volume
Post by: Strife89 on July 05, 2008, 11:39:36 AM
Volume is determined by the hardware.

Also, gain above 0dB introduce distortion.  If the target actually supported +10dB, its unlikely you'd like what you heard at that volume.

Distortion is less noticeable on a bus. :)
Title: Re: more volume
Post by: soap on July 05, 2008, 11:50:12 AM
A habit of turning up the volume in response to background noise is the quickest recipe for hearing loss through DAP usage I can think of.

The proper solution is either to give your ears a rest when in noisy environments or invest in noise isolating or canceling headphones.

As for loud track or loud peak detection, this is impossible.  There are many factors involved in the amount of energy which reaches your eardrum, and many of them (including headphone choice, headphone fit, and ear shape) are out of the control sphere of the DAP itself.
Title: Re: more volume
Post by: peter_s_d on July 06, 2008, 09:32:44 AM
I was thinking about noise cancelling earplugs anyway. 

The tracks that I am interested in are spoken voice files that I listen to once and delete, so prepossessing them would be tedious - and well beyond what my father could do. 

If it were known that some DAPs are louder than others, could just the quiet models be tweaked? 

<optimism mode>

Is volume compression possible?  Have you ever heard a cassette tape that has been recorded with dbx and played back without it?

That would keep the peak down to avoid hearing loss, but get the quiet voices over the noise floor. 

<end optimism> 

<outrageous optimism mode>

Could models with a microphone detect noisy environments and dynamically control the volume compression factor? 

<end outrageous optimism> 
Title: Re: more volume
Post by: Llorean on July 06, 2008, 10:16:07 AM
<realism>
Could the user just manually adjust the EQ to bring up frequencies that tend to be quieter, and save that config for later use on other voice files?
<end realism>
Title: Re: more volume
Post by: Strife89 on July 06, 2008, 01:32:06 PM
What about movies in the MPEG player? Most of my movies' soundtracks are at a ridiculously low volume, such that I can barely hear them - even in a quiet area - at my normal "music volume" (-30). In a car, they're impossible to hear even at +6.

My computer takes nearly a full day to process one movie, so going back to pump up the source volume is practically NOT an option anymore. :(
Title: Re: more volume
Post by: Llorean on July 06, 2008, 01:59:53 PM
You can reencode movies while copying the video stream much, MUCH more quickly. As well, the equalizer works for them too.
Title: Re: more volume
Post by: peter_s_d on July 07, 2008, 12:36:04 AM
O.K.  It looks like using the equaliser is the way to go at the moment.  There is an extra 24dB available! 

Is bumping the gain evenly in all frequency ranges *exactly* the same as increasing the volume by the same amount?  Nearly as good?  Or only a rough approximation?  I am not an audiophile and I am not listening to classical music, so the likely answer is, "You won't be able to tell the difference.". 

If you are really serious about protecting the stupid from themselves (an impossible task) then it would be better to limit the combination of volume + equaliser, rather than limit each individually. 
Title: Re: more volume
Post by: Llorean on July 07, 2008, 12:49:17 AM
It's not an issue of "protecting the stupid." The volume range is defined by the hardware. It already gets well louder than is often safe for the ears, but the amount provided is always the full volume range of the chip. Any additional loudness would have to be added digitally. Because of that it's exactly identical to what you'd get by increasing it with replaygain or a pre-amp.
Title: Re: more volume
Post by: Zardoz on July 07, 2008, 01:24:21 PM
I suggest using in-ear phones with a good fit, for better low frequency response and less 'attenuation' of the higher ends. maybe you already do? tuppence worth