[m_kos]

1. I find Tim's work always so impressive and humbling. Compared to software, hardware projects seem infinitely more complex.

2. Speaking of knobs, I am writing a toy software synth for smartphones. Are there any design guidelines for mobile UI for audio? Knobs are hard to use and sliders take up a lot of space with only a little more precision. I experimented with curved sliders (inverted parabola or sine), but they are confusing since height doesn't really encode anything and the curvature is there only to make the slider longer. I didn't find any design systems focused on audio components.

[ecolonsmak]

Knobs shouldn't be hard to use - hold down the knob that needs the adjustment and then drag in either of two directions to set the value. Maybe have a pop-up over the knob that displays the value as it's in use.

[m_kos]

Thanks! For me, this works well for knobs that don't require frequent adjustments. Currently, my knobs have little pills next to them that switch a knob to a "precision mode." It is a little quicker, but you may need to remember to disable this mode next time you use the knob.

I also played with the idea of letting users slide their finger off a knob (tap and slide away from the center). This allows for moving the finger over a longer circumference, hence enabling a great degree of precision. The problems with this approach are that it takes longer to operate such knobs, you need to communicate to the user what the max allowable distance from the knob is, it can interfere with scrolling, and it doesn't work for knobs close to the edge of the screen. (Your idea works well for knobs at the edges.)

And this is just knobs! There are many other components, interactions between them, as well as associated accessibility challenges, haptics, etc. Instead of reinventing the wheel, I was hoping that human factors people had developed relevant guidelines, but perhaps it simply is not a prevalent enough problem.

[recursive]

Loopy Pro has a cool convention that I haven't seen elsewhere for this. Drag up or down to change the knob value. While doing that, drag left or right to zoom in. That makes the up/down movement more precise.

[m_kos]

I will look into it! Is this for mobile or desktop? I would like to see how they introduce this interaction pattern and what feedback they provide as you interact with the knob.

[recursive]

It's an ios app. IMO it's really good. I own exactly one apple product, and it's an iPad that only runs Loopy Pro.

Here's a section from the manual that loosely explains the concept[1]:

> Adjust a slider or dial’s value by dragging up and down, or left and right for horizontal sliders. For finer control, move your finger away from the dial.

[1]: https://loopypro.com/manual/#sliders-and-dials

[m_kos]

Thanks! This link is really great!

My only Apple product is also an iPad, and I mostly use it to make music with Auxy Studio:)

Do you use any fun apps on Android? Currently, my favorite apps are Digitron and Nanoloop. (No affiliation, but Digitron's upgrade was gifted to me.)

[recursive]

The only other music or audio app I use with any regularity is Reaper on Windows. I tend to do more performance-oriented stuff, and I try to keep everything outside the computer as much as practical. I don't use any software synths. I like the constraints and UX of dialing patches into my one keyboard/drum machine. I record some, but mainly I like to play in real time and not fiddle with VSTs and plugins.