Logarithmic Sliders

[Edgar]

I assumed Ed was asking on your behalf of you as he is subscribed to the widgets list. But he can type a quick +1 if he wants to vote.

I'm neutral – generally, I hate logarithmic controls (and sliders in general) but realize that most users might find them more familiar. I did indeed ask on the wxWidgets list just in support of this topic.

I could probably do most of the programming to develop a logarithmic slider but would not know how to do the actual linear to logarithmic mathematical translation. That translation should not be too hard, I envision something like converting the original linear values (Max, Min & Value) into a percentage/ratio then using that result to determine the logarithmic value.

[steve]

generally, I hate logarithmic controls

I presume that you don't use the Mixerboard. Compared to "Mixer Windows" in other multi-track programs, the sliders in the Audacity Mixerboard are horribly clumsy.

This is a logarithmic slider.

log.png (7.58 KiB) Viewed 1854 times

[Edgar]

I hate logarithmic controls

I presume that you don't use the Mixerboard.
This is a logarithmic slider.

I do not use the Mixerboard. The reason I do not like logarithmic controls is that, generally, 75% or more of the range of the control is useless. Consider the typical output volume slider on a mixer desk; set everything to unity - mic gain, channel output, master output; set amplifier level for pleasant listening volume (or set the amplifier to unity and trim down the mic gain – your choice). Now reduce the master output, very quickly the perceived sound will disappear but there is still 50% to 75% of the slider control still available. I want much finer granularity across the entire range of the slider.

[Gale Andrews]

Looking at Steve's slider image, isn't the point of logarithmic sliders that you get most granularity over the most audibly important volume ranges?

My "objection" about log sliders is that they are harder for novices to understand. They know what a desk ruler looks like and don't understand anything else.


Gale

[steve]

Looking at Steve's slider image, isn't the point of logarithmic sliders that you get most granularity over the most audibly important volume ranges?

Absolutely. That is entirely the point.

For the sake of simplicity, let's say that you have a linear slider where 0 dB to -1 dB is 1 cm.
Taking < -96 dB as "silence", you need to drag the slider/mouse almost a meter from 0 dB to "silence".

On the other hand, with a logarithmic slider:
0 -> -1 dB = 1 cm
0 -> -2 dB = 2 cm
0 -> -4 dB = 3 cm
0 -> -8 dB = 4 cm
0 -> -16 dB = 5 cm
0 -> -32 dB - 6 cm
0 -> -64 dB = 7 cm
0 -> "silence" = 8 cm
which is much more realistic.

Looking at it the other way round, an 8 cm slider from 0 to -100 dB with a linear scale is 10 dB per cm, which is lousy granularity close to 0 dB.

[Edgar]

I see. I had not thought this through mathematically. I suppose my complaint would be even worse with a linear slider which used the same Max & Min. I still contend that way too much of the range of your typical hardware mixer deck is inaudible (given unity and proper gain structure everywhere else). Maybe what we need is something with even steeper slope.