Comment by jonesjohnson | Hacker News Reader

Comment by jonesjohnson | Hacker News Reader

The title is a bit misleading IMHO. It's more like analog vs digital. After all, from an electrical point of view they're usually just potentiometers and you can build them either as rotary or as linear potentiometers, but it's just a wiper on a resistive conductive track... (of course there are exceptions that work differently and use hall effect or optical sensors).

The article only talks about the actual circuit that is behind that potentiometer.

Having built some MIDI controllers myself in the past, I noticed that rotary potentiometers allow you to better "decouple" arm/shoulder movements from hand/finger movements. I.e. when you're standing and and holding that knob, It's easier to make precise adjustments when there's a rotary knob you can "hold on to" and slowly twist your fingers, whereas with a linear potentiometer I usually have to keep a finger on the surface next to the knob to "compensate" for involuntary movements coming from my body and arm...

Yes, this is the same for controls in a car. Whoever thought a touch display was the way to go? Our old car had twisty-nobs that you could feel direction already on the grip. No need to look on the symbols what they adjusted. Our "modern" car has still twisty-nobs (we made extra sure of that) but you can't feel the direction because they are perfectly round with a tiny tiny nob for direction. Why do I get the impression development goes backwards?

> Whoever thought a touch display was the way to go?

A lot of people talk about as it was primarily a design decision, but I suspect touch screen controls are the cheapest one out there right now.

Especially when sisterly countries with sisterly regulations are taken into account.

The hardware is much cheaper, but it is also way cheaper to engineer, and because a touchscreen is a very one-dimensional interface, many questions don't even need to be asked. There's no texture, shape or feedback in a touchscreen, for example.

Are there physical controls that mount on a digitizer? E.g. instead of a rotary dial on a potentiometer, the bottom sits on a digitizer that can translate the "touch" event into circular motion. Same with buttons, like with a keyboard membrane, but capacitive. Wouldn't that be cheaper?

That’s not addressing the right issue. Encoders and switches are not the expensive parts. What’s expensive is designing the dashboard with precise holes, before you actually start the manufacturing process, lining up the component with the hole and cap, making sure they actually work etc. Compare that to a dashboard of the new Tesla robo taxi, which basically has a complexity of a TV mount.

But you don't need to line up the holes if you can just plonk the component down anywhere and then program the software with the locations of the components after the fact.

Ford does this on the MachE and I think the F150L. They have a rotary dial for volume control and that is just mounted directly to the touch screen and uses some sort of wipers to make contact for the control surface.

BMW is a good example. They started putting in that horrendous double wide screen/touch screen removing all buttons (the radio 1-8 shortcuts), temperature, heated seats, fan speed etc onto the screen.

This of course has made their dash design a lot cheaper. The only things remaining are:

Volume (which can be pressed for on/off/play/pause), previous, next, park-anywhere-button, front and rear windshield defroster.

One thing that is amazing about BMW's volume control:

It clicks, but the clicks don't corelate directly with volume change. It depends on how fast you turn the knob. Turn it 5 positions slow = volume += 10. Turn it 5 positions fast = volume += 5. To prevent you from accidently turning it too fast and blowing up your eardrums.

Is that volume behaviour intentional, or just crappy sampling rate of the encoder?

Good question. Either way it works. Imagine adjusting the volume and going over a bump.

Does it work the same way when turning the volume down?

I'll test that. But that might be a month or so as I WHF.

BMW actually seems to be quite intentional with details like this. For those who appreciate thoughtful human-centered design, it quickly becomes clear that many of their choices reflect unusually meticulous work and attention to detail. But I wonder if this is shifting, as fewer people seem to understand the difference.

This is also my experience. I'm not a DJ but I perform live electronic music using various MIDI controllers. If I quickly want to add or remove a sound, like a kick drum, to/from the mix, a slider is best. If I need fine control over a parameter, like a low-pass filter frequency, a rotary controller is usually better for the reasons you mentioned.

As alluded to in the article, rotary vs. linear seems to be a proxy for the circuit which actually influences the sound. I would think that anyone claiming "mixers with rotaries always sound better" does not fully understand how they work. There's a lot of those kind of claims in the music scene.

Though it's easy to see why linear potentiometers make sense if you want to adjust multiple at the same time.

However in these modern days with motor driven potentiometers, I guess it is less of a big deal.

That’s not generally the use case for DJ mixers.

True, but not all mixers are DJ mixers.

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