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Subject: Re: Sound quality with Rockbox
From: George Styles (george_at_ripnet.co.uk)
Date: 2002-12-09


I see. thanks

g

----- Original Message -----
From: "Linus Nielsen Feltzing" <linus_at_haxx.se>
To: <rockbox_at_cool.haxx.se>
Sent: Monday, December 09, 2002 10:29 AM
Subject: Re: Sound quality with Rockbox

> George Styles wrote:
> > i also have the subjective idea that the Archos sounds slightly better,
but
> > I have not experimented with the various settings etc. it may be
something
> > as simple as the default loudness setting...
>
> I think so too. There is little we can do about it. Still, I can add
> some new interesting settings for the Super Bass that are hard coded at
> the moment. For all tweakers out there.
>
> > what do u mean by digital distortion? do you mean a buffer overload, or
are
> > you scaling the MP3 data somehow so its clipping?
>
> We don't do anything to the MP3 data, we just pass it to the MAS DSP.
>
> The MAS DSP processes the audio according to our settings (Bass, Treble,
> Loudness, Volume) without any compensation for overflow in the
calculations.
>
> This means that we must make sure that the sum of the settings do not
> exceed 0dB. If we set Bass/Treble to 6dB, we must set the volume to -6dB
> to prevent overflow. We do not do that today, mostly because of
> lazyness, but also because we want to allow people to use the settings
> they want. You *can* set Bass to +12dB and still get no clipping, either
> because the volume is low enough, or that the mp3 audio has a generally
> low level so clipping does not occur.
>
> If we add a compensation algorithm, people will not be able to listen to
> low level audio.
>
> I still intend to add compensation, but only as an option for those who
> need to set the bass/treble/loudness high and don't want to adjust the
> volume themselves.
>
> /Linus
>
>



Page was last modified "Jan 10 2012" The Rockbox Crew
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