[pulseaudio-discuss] 24 bit sound

[David Björkevik]

On 2010-05-07 04:38, Tanu Kaskinen wrote:
> On Fri, 2010-05-07 at 00:22 +0200, David Björkevik wrote:
>> I'm in the process of buying a new soundcard. For a little more money I
>> can get a 24-bit one, which I figure would be nice for things like
>> software mixing.
> 
> What's your use case? You don't mention recording / audio production, so
> I'm assuming that you are mainly interested in the sound quality for
> music listening. I'm extremely skeptical about 24 bit making any
> perceivable difference for mixing multiple output streams together, and
> in the case where quality really matters, i.e. music listening, you tend
> not to have multiple output streams in the first place.
> 
>> However, I can't find anything on how PulseAudio handles audio above 16
>> bit / 48KHz. Will my 24-bit upgrade be lost in software?
> 
> Pulseaudio should handle 24-bit hardware just fine.
> 
>> Also, what about higher frequencies, 96KHz and upwards?
> 
> Pulseaudio should handle any sample rate just fine. Again, I don't
> believe you actually gain anything from higher sample rate, all other
> things being equal. Now, when comparing a higher-spec sound card to the
> cheapest available consumer card, all things might not be equal - the
> bit depth and sample rate don't determine the sound quality, but other
> aspects might very well make the higher-specced card sound better.

Sorry for being a bit vague. I'm aware of what you state about cards
that have high sample rate and bit depth. The only thing I really wanted
to know was:

  * If I buy a 96kHz / 24 bit card, use PulseAudio, and play such a
.wav-file through mplayer, is that the rate and depth of audio that will
be sent to the sound card?
 * With such a card, if I disable the alsa mixer and just use software
mixing in PulseAudio, will the full 24 bit depth be utilized,
effectively causing little or no degradation on sound quality when
playing back a 16 bit sample?

Given what you state above, I take it that the answer to both of these
questions is yes. If not, please scream now and I will not spend an
extra penny going above 16bit/48kHz. Whether or not I actually will hear
the difference above standard CD quality is a valid question to raise,
but probably OT on this list.

Regards,
David