#219: How Wave Observer Reveals What Softube Saturation Knob Really Does

Ever twist a saturation knob and wonder if you’re hearing compression, distortion, or something in between? In this episode of Inside The Mix, Marc Matthews puts that question to the test with a clean, scientific setup, a 440 Hz sine wave, the Softube Saturation Knob, and Wave Observer, a free oscilloscope plugin by Press Play.

By placing Wave Observer last in the signal chain, Marc visually shows how your waveform changes as you dial in saturation, how rounded peaks flatten, harmonics stack up, and a pure sine wave slowly edges toward a square. No more guessing, no more placebo, just a clear visual of how your favourite plugins reshape the sound.

Marc explains why visual feedback matters when subtle processing tricks your ears, and walks you through a simple DIY method you can try in any DAW. You’ll see exactly what happens around -12 dBFS, where soft saturation tightens dynamics long before the audible grit appears.

This quick session helps you connect what you hear to what you see — so you can mix faster, gain stage with intention, and start trusting your ears with confidence.

Takeaways:

• How to use Wave Observer for real-time saturation analysis
• What clipping actually looks like
• A repeatable workflow for plugin testing and calibration

If you’re ready to stop mixing blind and start seeing your decisions pay off, on meters, waveforms, and final masters — this one’s for you.

Subscribe, share the episode with a producer friend, and drop Marc a note with the next plugin you want analysed. Your suggestion might feature in a future episode of Inside The Mix.

Links mentioned in this episode:

Press Play Wave Observer

FREE Plugin To See Inside Your Mixes - Press Play Wave Observer

Chapters

• 0:56 Why Blind Tweaking Hurts Your Mix
• 1:12 Meet Wave Observer: Free Oscilloscope Plugin by Press Play
• 2:23 Listener Question: What Does Saturation Actually Do?
• 2:51 Why Every Producer Should Use an Oscilloscope
• 3:24 Quick Survey: Shape Future Inside The Mix Episodes
• 4:10 Wave Observer in Action: Reading the Display
• 4:28 Test Tone Setup: 440 Hz Sine Wave Explained
• 5:11 Softube Saturation Knob Demo: Seeing the Harmonics Build
• 6:34 Key Takeaways: Visual Mixing and Gain Staging Tips
• 8:16 Support the Show & Related Episodes

Transcript

Marc Matthews: 0:28

Have you ever turned the knob on a plugin and thought, what exactly is happening to my audio right now? Maybe you're using a saturation plugin and you're twisting that dial thinking, can I hear compression? Can I hear distortion? Or can I hear something else entirely? Or maybe my ears are fooling me altogether. Here's the twist. You don't have to guess. There is a free plugin called Wave Observer by Press Play, and you can use it to analyze what your plugin is actually doing to your audio. And I'm going to use it in this episode with one of my favorite free plugins. So how can you use Wave Observer to visually understand your plugins? Let's dive in. You're listening to the Inside the Mix podcast with your host, Mark Matthews. Welcome to Inside the Mix, your go-to podcast for music creation and production. Whether you're crafting your first track or refining your mixing skills, join me each week for expert interviews, practical tutorials, and insights to help you level up your music and smash it in the music industry. Let's dive in. Hey folks, welcome to Inside the Mix and a big welcome if you are a new listener or viewer, if you're watching on YouTube, and a big welcome back to all the returning listeners and viewers. Now, this episode I am demonstrating a great free plugin that I discovered recently called Wave Observer. And it's brought to us by Press Play. Now, disclaimer, this episode is in no way, shape, or form sponsored by Press Play. It is literally me just sharing, sharing with you a plugin I discovered recently that I think you'll enjoy. This all started when a listener asked a brilliant question on episode 214, the best free plugins every producer should use. And the question is this What does that soft tube saturation do? Shave Peaks and Audibly, because you have to crank that dial a lot to get it to audibly distort things. And honestly, great question. And it made me realize that I don't have a plugin that allows me to see what effect a plugin is having on my audio. So I started scouring the internet for free time domain audio analysis plugins, and I discovered, or rather, stumbled across the oscilloscope that is Wave Observer by Press Play. Now, this isn't a tutorial or episode on how to use Wave Observer. There are fantastic ones that already exist online, and I'll put a link to one of my favorites in the episode description. This is just me describing how I used it to answer that question way back at the beginning of the episode of what exactly is SoftTube Saturation Knob doing to the audio. But before we go any deeper, I have put together a quick two-minute survey and I want your input on the podcast, on how I'm going to shape the podcast in 2026. So click the link in the episode description and just give some feedback on the podcast itself and what you want to see or rather hear more of in 2026. And you can also in there share your music win of 2025 and get featured on episode 227, which is going to be the last episode of two of 2025. So click that link in the episode description. Let me know what you want to see more of in 2026 and maybe what you want to see less of in 2026 on the podcast. And also share your win and feature on the podcast in the very last episode of the year. So click that link in the episode description. So what is Wave Observer? It's basically an oscilloscope that you can use for time domain audio analysis. So we can use it to understand how peaks, transient response, and waveform shape change as we process audio using plugins. So I've got Wave Observer here, and it is last in my signal chain. It's after my test oscillator, which is a sine wave at 440 Hertz, which is A above middle C. I recommend trying it out on some more complex material like a drum loop or on a vocal, for example. Specifically, if you're using something like saturation knob, because you've got the keep high, neutral, and keep low, which can be quite interesting to try out. So when I enable this test tone, I'm gonna see the sine wave in Wave Observer, and I'm in the mode waveform. If you want to know what the mode duration and zoom do, go check out that link in the episode description, and there's a brilliant tutorial where it goes in more depth with that. But what I'm gonna do is I'm gonna enable the test tone, and you'll just hear a sine wave. Okay, and we can see that in Wave Observer, which is great. So what I'm gonna do is I'm gonna enable soft tube saturation. And this is what I did after that uh in response to that question, and I thought, okay, the question was, do you have to really crank it for it to actually do any form of basically clipping the audio? It uh it essentially turns it into a square wave. So I'm gonna leave it on neutral and I'm just gonna crank it. Now it's gonna get a bit loud when I do that. So in my post-production, I'll try and bring that down. So let's uh enable the test home and hopefully as I crank the saturation on soft tube saturation, you'll start to hear that waveform changing shape basically. It's turning into a square wave because it's shaving off the top. Okay, so there we go. That's quite pronounced, isn't it? And that is soft tube, that's at 6.3. So I'm just gonna drag it up again until we start to really. I mean, again, that was quite pronounced. I'm gonna drag it up again on the on the sine wave. So that's three. That's not really that far on the saturation obs. You don't really need to do a great deal. Now, this sine wave is set at minus 12 dB in terms of output with the with the test oscillator. So you don't need to do a great deal, but you get this sort of square wave, and that's it. That's how I used Wave Observer to answer that question. I didn't really need to crank it a great deal to get that waveform to start changing shape. But again, trial it on your own material, try it on more complex material. It's a great way, it's a great tool to use to visually understand or start to understand what effect a plug-in is having on your audio. And I've really only scratched the surface with this. And I love doing these kind of episodes where I find a new tool, a new plugin, because I can share my experience and then get feedback from you and how you've used it and how you are using it as well. So I love doing these particular episodes. And again, click that link in the episode description if you want to get a deep dive into actually what and how to use Wave Observer. Now it's your turn. What plugin are you going to analyze using Wave Observer? Maybe a tape emulation plugin, maybe your favorite compressor. Maybe you found a new distortion plugin that you really want to analyze and see what it's doing to your audio. Shoot me a message. Click that link in the episode description as I'd love to know what plugin you analyze using Wave Observer, or maybe you've got a different tool that you use to analyze your audio, or rather, analyze your plugins and what they're doing to your audio. Shoot me a message and let me know, and I'll feature it on a future episode. So there you have it. And of course, I'll put a link in the episode description. My biggest takeaway, sometimes visualizing your signal can identify something your ears might have mixed. And this is especially useful if you're using a new tool for the first time. And before we wrap things up, if you would like to support the podcast and what I'm doing here at Inside the Mix, consider joining the YouTube membership for less than the price of a coffee per month. And I love coffee. You'll get priority reply to messages, badges, and early access to new episodes. Just hit that big, I think it's blue, hit that big blue join button on YouTube. And if you like this episode, check out episode 203 of the podcast, where I chat with Ian Stewart, who breaks down what actually happens when you choose a sample rate, the perfect follow on from this episode. Until next time, keep creating, keep producing, and I'll catch you in the next episode.