SOL-1 Pro – Batch LUFS Optimizer (Standalone, A/B Comparison)

[SOL Studio]

Hi everyone,

I’ve just released a standalone loudness optimizer for Windows.

It’s designed to quickly match loudness across multiple WAV files using adjustable LUFS targets — without opening a DAW.

Just drop your files, compare before/after, and export optimized versions.



Key features:

Batch LUFS normalization (multiple files at once)
Adjustable target LUFS (streaming-ready)
True Peak control
Real-time A/B comparison playback
Waveform analysis

This is especially useful if you:

prepare multiple tracks for streaming (Spotify / YouTube)
want consistent loudness across albums or demos
don’t want to open a DAW for simple loudness work

Demo video:

Website: http://solstudio.online/

Available on Gumroad: https://solstudioaudio.gumroad.com/l/xtvytv
7-day free trial available
Intro price: $29 (regular $49)

I’d love to hear your feedback!

[SOL Studio]

Just a quick note:
If you get a security prompt when clicking links, just proceed — it’s a standard KVR protection.

Also, the demo video shows a quick A/B comparison and batch workflow.

[SOL Studio]

Just to clarify a bit more on how I use this:

I mainly built SOL-1 Pro for quickly matching loudness across multiple tracks — especially useful when preparing albums, demos, or client previews where consistency matters.

Instead of opening a DAW, you can just drop files, set a target LUFS, and export matched WAVs in one go.

The A/B comparison also helps quickly check if the processing is affecting the perceived balance.

[Zeisner]

https://productionadvice.co.uk/equal-lufs/

[SOL Studio]

Thanks for sharing the link! Ian makes a very valid point, and I completely agree.

Hitting a specific LUFS target doesn't automatically make tracks sound equally big or punchy, and streaming normalization definitely changes how we need to approach loudness matching.

That said, I built SOL-1 Pro mainly for workflow and utility situations, such as:

- Preparing multiple tracks (albums, demos, client previews)

- Keeping perceived loudness consistent across files before distribution

- Quick comparisons without relying on a DAW or platform normalization

So it’s less about “winning the loudness war” and more about saving time and ensuring consistency during the preparation stage.

[Zeisner]

LUFS is better than RMS but it's still a (rather faulty) compromise. Better loudness measurement methods and models exist but they need more processing power which makes them inefficient for large systems which have to deal with billions of files fast. But for tools like yours they would do a much better job (and users have the required processing power anyway) so I recommend to take a look at what is out there. It would also help your software to stick out of the "LUFS crowd".

[SOL Studio]

That is a brilliant insight. Thank you so much for the detailed feedback!

You are absolutely right that a dedicated desktop tool has the processing power to use better perceptual loudness models, and it's a fascinating idea. To be completely honest, implementing those highly complex algorithms might be a bit beyond my current technical focus, but it's definitely something I want to research for the future.

Actually, my original vision for SOL-1 Pro was a bit different. My main driving question was: "Can I create something with a far better, faster, and more intuitive workflow than existing tools like Streamliner, Metric AB, BUTE Loudness Normaliser, or EXPOSE 2?"

That focus on ultimate usability and eliminating preparation friction is exactly how SOL-1 Pro was born. So while it may use standard LUFS right now, the core identity of the software is all about making the preparation process as painless and efficient as possible.

I really appreciate your perspective—it helps me think about how to evolve the tool to stand out even more!

[Zeisner]

I remember at least three really good loudness measurement algorithms for music content (better than LUFS) from Researchgate. I can't guarantee that I will find them but I will have a look at my PDF archive. There's more code to write because those algorithms use more filters but it should be doable for someone who can code the filters required for LUFS.

[SOL Studio]

Thank you so much for taking the time to look for those PDFs!

To be completely honest, I'm actually a former music producer, not a DSP engineer or a hardcore coder. I rely heavily on established frameworks for the complex DSP math. I basically started making plugins just to solve the workflow frustrations I experienced during my producing days.

So, coding advanced perceptual filters from scratch based on academic papers is definitely beyond my current technical skills!

While the heavy math in those papers might go completely over my head, I am always interested in the basic concept of why certain tools sound or work better. I really appreciate your willingness to share, but please don't spend too much time digging through your archives on my account!

[Zeisner]

The filters in those papers are usually just standard IIR filters, you can find code for them all over the web. Some papers even include the code used. I also need to sort my archive anyway.

[SOL Studio]

Ah, I see! If it’s mostly standard IIR filters, that sounds a bit less intimidating than the crazy complex math I was imagining!

Still, my biggest daily battle is just keeping my C++ code stable and ensuring the workflow stays fast and intuitive.

But if you happen to find those papers while sorting your archive, I’d be very grateful to read them. Even just understanding the concepts behind those better algorithms is highly inspiring for me as a tool creator.