db volume scaling

[Jeff Mitchell]

Tim Blechmann wrote:
>>> still, a few questions:
>>> - when i want to reduce the volume by 6 db in the decibel scale, how
>>> much do i have to reduce the volume in amarok's percent scale?

Get a calculator.

>> What one cares about for Amarok is: Is this too loud? Yes. -> Make it
>> less loud!" or "Is this not loud enough? Yes. -> Make it louder!"
>> (Amarok is not a DJ application, mixer or the like.)
> 
> for question one, yes. i know, how it sounds, when i change the volume
> by a certain amount of decibel.
> when i want to make it a bit louder, i increase the volume by 2 or 3 db,

Add 10%

> if i have a high volume and want to reduce it a lot, i reduce it by 20
> db

Subtract 40%

> ... no matter, if i am currently listening at -6, -12 or -20 db ...

... no matter, if you are currently listening at 20, or 60, or 80%

> question two was more a rhetorical question to show, that amarok's
> percent scale does not work well for a quantitative description of volume.

Question two is bogus anyways.  Adjusting Amarok's volume slider changes
Amarok's relative volume level.  Regardless of whether it is in dB or
percentage, there are other factors (multiple ALSA sliders, for
instance) that affect the actual output audio volume.  This also varies
by sound card, among other factors.  In other words:

> - when setup A is 10 db louder than setup B (setup A may be the studio,
> setup B the living room). how much do i have to increase the volume in
> amarok's percent scale to get the same sound pressure level, if my
> default playback volume is (a) 20% or (b) 50%?

Assuming everything is equal -- sound card, system, all other sliders
and equipment and factors, so that Amarok's volume level is the *only*
difference -- you need to increase the volume on setup B until the
percentage on setup B matches the percentage on setup A.  (Duh.)

--Jeff

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: OpenPGP digital signature
URL: <http://mail.kde.org/pipermail/amarok/attachments/20090609/d8d6921c/attachment.sig>