Late last year, we unveiled SoundSource 6, the latest and greatest version of our essential audio control utility. This upgrade added substantial new functionality, without drastically overhauling the nimble interface that was already familiar to countless users.

Today, I want to talk about a few of the design puzzles we had to solve while developing SoundSource 6.

Initial Design Inspirations

We advertise SoundSource as “sound control so good, it ought to be built in to MacOS”, and we want it to feel like part of the system. That led us to take some cues from the system-level control centre as it existed when we began work on SoundSource 6. This is the control centre from MacOS 15 (Sequoia):

The visual blocks and sections seen here inspired our own layout. At one point, we even played around with using similar chunky sliders. Here’s how an early mockup of that looked in SoundSource:

That was initially appealing, as the overlapping volume icon in the slider saved several dozen pixels, particularly helpful for our small interface. However, we soon noted an issue with these combined chubby sliders. We use the volume icon itself as a mute toggle. If the level is low, how can we tell if the user is trying to grab the slider knob or click the mute button?

Though we found ways to make it work, we didn’t like the possible confusion it could cause, and ultimately moved away from this idea. We weren’t too surprised when Apple themselves ditched this approach in the control centre in MacOS 26 (Tahoe). Some other changes they made in Tahoe were quite surprising indeed, however.

Enter Liquid Glass

During WWDC 2025, with SoundSource 6’s beta period already in full swing, Apple unveiled their new “Liquid Glass” design language. Where the Sequoia control centre had provided inspiration, the Tahoe control center offered only eye strain:

In addition to losing those overlapping icons and chunky tracks, sliders in the control centre also lost their knobs for some reason, at least until you hover over them. And as you can see, Tahoe’s control centre is both less compact and less legible than the previous version, but at least it’s also ugly.¹ When we saw this change, we quickly determined that SoundSource would not be following in its footsteps.

We work hard to make sure our products look and feel right on the Mac, but we’ve never been afraid to ignore Apple’s lesser design whims.² We want our apps to exist harmoniously alongside Apple’s designs, but they don’t need to match exactly. Notably, the actual glass part of Liquid Glass is something we’re mostly steering clear of in our own designs.

Breaking Our Icon Out of Jail

Liquid Glass wasn’t the only change to be seen in Tahoe. Apple also messed with app icons, necessitating an update to SoundSource’s icon:

This modification was minor, but it was also rather frustrating, as it came due to Apple’s oppressive design approach. To explain, a little background is needed.

Starting with MacOS 11 (Big Sur) in 2020, Apple decided to make all their Mac app icons into squircle tile shapes, matching the look of apps on the iPhone.

Apple encouraged developers to follow in their squircley footsteps. Though having all icons use the same shape makes it more difficult to tell them apart, we did our best to roll with this change, while still retaining a bit of individuality. Some of our icons fit the general squircle shape, but had elements which subtly broke the frame. We stuck with those accents, as they made icons easier to pick out, and gave them a bit more character.

In the image above, the pink area shows Apple’s desired shape. The wand in SoundSource 5’s icon and the mic in Audio Hijack’s old icon broke out of that frame slightly.³

For several years, these icons worked just fine. They fit in with the general aesthetic Apple sought, while maintaining some personality. Regrettably, with Tahoe, Apple decided to enforce their exact desired squircle shape on every single app. If an icon deviated, it was aggressively cropped down and imprisoned on an ugly grey background.

Given Apple’s heavy-handedness, we felt forced to make a change. Though SoundSource’s icon doesn’t show up in the dock, it does show up elsewhere in the Finder, and the grey icon jail makes it smaller and more difficult to pick out. Updating SoundSource’s icon was fortunately pretty minor, with the magic wand just moving into the centre of the icon. Still, it was a change wrought by Apple that we did not relish making.

Concentricity

By contrast, one aspect of Tahoe’s updated design that I’ve been delighted by is concentricity. That’s a jargony way of say that rounded elements in an interface are drawn as if their circular elements share a centre.

To see this in action, look at the following example from SoundSource’s “Quick Configs” menu. Notice how the semi-circle of the selector and the quarter-circle of the app window, if drawn out, would share the same centre:

The visual effect of these concentric circles is just nice. Much as music notes in a chord elevate each other and are pleasing to the ear, concentricity is satisfying to my eye. Tahoe’s focus on it is a refreshing aspect of Apple’s new design. For this particular designer, it shines like a good deed in a weary world, and it’s an element of the new design I was very happy to embrace.

Keeping an Agile App Posture

Beyond dealing with changes Apple made to the MacOS, we also had to solve the challenge of adding substantial new power to SoundSource while still keeping its interface fast and compact. This was no mean feat.

When considering the overall design of an app, it’s often helpful to think about what I call its “posture”, its size and how it carries itself on your system. For example, a big, complex app like Photoshop takes over your whole screen, providing a deep work environment unto itself. SoundSource is almost the polar opposite, a small and streamlined app that mostly runs in the background. It’s something you’ll dip into briefly to tweak a few settings, and then get back to what you were doing.

In SoundSource’s earliest versions, it was positively tiny. Here’s a screenshot from our archives, which shows the entirety of the interface for the first version:

The barebones nature of the original SoundSource made an unobtrusive posture come naturally. Maintaining that lightness in the feature-rich modern SoundSource is much more difficult. In contrast with the above, here’s SoundSource 6’s main window:

Even if you’ve never used any version of SoundSource, it’s obvious from these two screenshots that the app does a lot more for you these days. The recent upgrade to SoundSource 6 added many new features, including audio device configuration options, AirPlay support, and customizable output groups. It took a great deal of thinking, and many mockups and iterations, to fit all that new functionality into our compact menu bar app.

Controlling Audio Devices

One notable example of this iteration was just how we provide the aforementioned audio device configuration options. These are things like adjusting volume, balance, and sample rate for any and all audio devices you have plugged in to your Mac. My first instinct was to add a new “Devices” tab into the app’s “Settings” window. Here’s an early sketch:

While this made some sense in terms of navigation, it shoehorned way too much into a very small space. As we continued to add options to this area, it became less and less workable. Eventually, it was clear that these settings deserved their own window. Thus, the “Audio Devices” window was born:

Moving these controls to a distinct window provided the new features with a solid home, and leaves us room to add more in the future as well. We ultimately added several secondary windows in SoundSource 6. They’re easy to access from the main window, while avoiding making the app feel cluttered. Even with all of its new features, SoundSource is able to maintain its overall lightweight posture.

Wrapping Up

Those were just some of the design challenges that arose during the development of SoundSource 6. Figuring out solutions to them produced the app you see today. While SoundSource’s visible surface area remains small, it’s become a surprisingly deep application when it comes to functionality. The app is part ninja and part knight on horseback, part bicycle and part big rig. I’m proud that we’ve been able to wrap up so much power into such a nimble interface.

When I find myself at a Mac that doesn’t have SoundSource installed, it genuinely feels like something is missing. If you’re already a SoundSource user but haven’t tried version 6, check out the “What’s New” page and download the new version. And if you’re new to SoundSource, head over to its product page to learn more, and download the free trial.

Footnotes:

1. It’s outside the scope of this design breakdown, but I attribute much of the poor design in Liquid Glass to Apple over-centralizing. Beyond the immediate negative feelings toward blurry glass on the Mac, I really don’t like seeing identical visual styles everywhere, from the Mac to the iPhone and beyond. Different platforms have different needs, and require distinct solutions. Too much uniformity can definitely be a bad thing. ↩︎

2. Though Rogue Amoeba has been around since 2002, you won’t find any brushed metal in our past, to cite just one example. ↩︎

3. Worth noting, on MacOS 11 – MacOS 15, many of Apple’s icons included their own framebreakers. These included Preview’s loupe, Automator’s inanimate carbon rod, and Chess’s knight. ↩︎