unity-design team mailing list archive

[Martín Soto <donsoto@xxxxxxxxx>]

2010/5/3 Diego Moya <turingt@xxxxxxxxx>

Norman's direct mapping would be the best model if each application
> had volume completely independent of each other. This isn't true
> though, as there is a system-wide volume control that changes all
> applications at once, thus making individual application volumes
> relative to each other.
>

IMO, we should start by getting rid of the system-wide volume. It adds lots
of complexity without providing any significant advantages. A global volume
control is useful when you're mixing several channels, but this is not what
people will be doing with the default volume controls in Ubuntu. And the
problem is that the global control negatively affects even the simplest and
most common use cases.

Consider, for instance, someone who is listening to a single sound source,
such as a music or video player. I'd say this is, by far, the most common
use case we have. Unless you're a sound engineer or some such, this is what
you're likely to be doing 99% of the time your sound card is active.

Setting the volume in this case should be absolutely straightforward but
it's not in current Ubuntu. You have to deal with two sliders, one usually
inside the player (e.g., the button/slider in Rhythmbox's top-right corner)
and one in the volume indicator that interact with each other in a funny,
unintuitive way. Sliding any of them down, for example, will mute sound, but
if you want to reach the maximal volume, you'll have to slide them *both*
all the way up. Of course, if you understand that the sliders correspond to
two separate volume filters that are connected serially, you'll be able to
deal with this system just fine. But most people won't grasp this--or at
least, it will be a long time until they do--and they'll be confused and
frustrated.

A centralized control that shows in one place the relative weights of
> all applications is a good design in this case, IMHO.


You speak about "all applications". How many applications do you expect to
have running and producing sound at a given time? I'd expect a maximum of
two, and that only for the relatively unusual cases where people talk on the
Internet phone and listen to music or watch videos at the same time.


> This way one can
> give more or less emphasis to one application with respect to the
> others, without having to switch between applications.
>

My guess is that this relative control would be unintuitive for most people.
All sound sources they deal with in the real world (TV, stereo, phone, etc.)
have absolute volume controls, not relative ones. If you want to talk on the
phone and listen to music at the same time (which is rather unusual because
most people will turn off the radio, anyway) you just fiddle a bit with both
the phone and the radio until it's OK for you. It is not that you turn a big
"Room Loudness" knob until you're satisfied, and then adjust the "Radio" and
"Phone" relative knobs behind that panel in the wall. A design where you
directly control the absolute volume of applications is likely to be a lot
more familiar to people.

This doesn't means one couldn't also have one standard application
> volume control for each application as a windicator; in this case,
> having redundant controls wouldn't hurt - as they support different
> use cases (controlling sound in the current application vs setting
> global sound preferences).
>

 I'm still not sure about the ideal location for individual controls. Having
them inside the application windows (either as part of the app or as
windicators) will definitely help people to associate them with the right
application. A central control may still be useful in some cases (like
quickly muting whatever is sounding) so this may be a situation where
redundancy is worth its price.

Cheers,

Martín