The Story of Dirac FilterLab: Great Technology Deserves a Great Tuning Tool

Our flagship automotive technology Dirac Unison uses our most advanced signal processing methods, enabling speakers within a system to work together to optimally reproduce each input channel–something which was previously impossible in digital room correction. While it’s a product we’ve always been proud of, up until January this year, the prototype tuning tool that came with it was not. It definitely worked, and offered all the required settings. But it was hard to maintain, and far from user-friendly.

We’ve long believed that Dirac Unison deserves a software tool that mirrors the elegance and high quality it delivers to the listener and tuning engineer. We wanted a tool that would truly reflect the three equivalent vectors of Unison’s unique selling proposition: Tuning speed, consistency, and sound quality. So finally, on January 27, 2017, we accomplished just that with the release of Dirac FilterLab. With Dirac FilterLab, things done changed and we can now offer a so fresh, so clean and user-friendly interface that reflects the algorithm’s strength through interface design. But getting here hasn’t been that simple. 


Designing, developing and delivering such a tool was a bumpy road, to say the least.       

The idea for a new tuning tool framework had been flying around the Dirac HQ in Uppsala for quite some time. In fact, a little too much time. We were excited and tumbling around in the realm of imagination for what this framework could be. But somewhere along the way we lost focus. We missed two delivery deadlines, which was bad. Really bad. 

So we sat down together, rolled up our sleeves, analyzed the situation step by step, and shuffled things around—a painful process. What a job. The good thing is, we learned a lot from our mistakes and came out strong, stronger than ever. The team’s newfound focus and dedication to the project has been outstanding and we’ve seen to it, by all means necessary, that we haven't missed a single release date for Dirac FilterLab since.


Growing up: From first draft to true team player    

I recently found an early sketch illustrating one of the initial ideas for the Unison interface and it got me reflecting on how far we’ve come. But before I explain this early idea, here’s a brief introduction to Dirac Unison, for those who are unfamiliar:

Dirac Unison provides perfectly tuned and integrated sets of combined loudspeakers. Each system input channel is associated with one loudspeaker, referred to as the main speaker. In addition, a set of supporting loudspeakers is defined for each input channel. The result is one perfectly integrated Unison channel for each input channel. For example, the left input channel of a 5.1 surround source is associated with the left front tweeter, which is supported by the left front midrange and left door woofer of a car sound system. This results in a combined three-way speaker, with a flat frequency response, perfect alignment, and cross-over settings between the three individual loudspeakers. The loudspeakers cooperate as one Unison channel, where cooperation replaces interference.

The main challenge for UI design was figuring out how to integrate all of these settings into one easy to use, easy to grasp interface.

The main challenge for UI design was figuring out how to integrate all of these settings into one easy to use, easy to grasp interface. A reasonable car sound system comprises 12 loudspeaker channels. The source material is typically 5.1 or 7.1 surround sound. For Dirac Unison, that results in 6 or 8 Unison channels, each with one main speaker and a number of support loudspeakers, typically between 3 and 6. Accordingly, there are settings for around 40 loudspeakers and 6 to 8 Unison channels.

  Figure 1:    Can you work with that   ? An early draft of the Unison filter design interface.

Figure 1: Can you work with that? An early draft of the Unison filter design interface.

So here is the early draft I was talking about. It illustrates the central idea behind the Unison filter design interface, presenting the entire system in a clear fashion. Each row corresponds to a Unison channel and each block corresponds to a set of loudspeaker settings. Color coding is used to show different sets of parameters. With this simple trick, the sensational load for the user is limited and a clear system overview is provided.

If you now take a look at the screenshot of the Unison filter design interface in FilterLab below, it ain’t hard to tell that, it in the end, it was this very idea shown in the draft that we ended up pursuing. Needless to say, we spent countless hours (and after hours) working to refine the idea.

  Figure 2:    Watch the sound    - The Dirac Unison design interface in FilterLab

Figure 2: Watch the sound - The Dirac Unison design interface in FilterLab

While it’s obvious that the final interface differs quite a bit from the early draft, its essential sprit is preserved. Despite the sheer endless numbers of parameters and settings Unison does offer, the interface is not overloaded. The desired, easy to grasp overview of the system has been successfully achieved. A skilled tuning engineer can set up the system in a matter of minutes. Can it be all so simple? Given the final result—yes. Once we discovered a proper way to present the technology to the user, everything ended up looking pretty simple.

With FilterLab, Dirac Unison has evolved from being a very much loved, but often stubborn teen, to a full grown, flamboyant adult.

Growing up hasn’t been that easy for Dirac FilterLab. With Unison, the software has evolved from a bold idea to a great piece of software art. Growing up hasn’t been so easy for Dirac Unison either. With FilterLab, the technology has evolved from being a very much loved, but often stubborn teen, to a full grown, flamboyant adult. Without a doubt, together they form the most awesome team, ready to rock on, and ready to welcome new, upcoming team members like Dirac Virtual Center.

If you want to find out more about our automotive technology offerings like Dirac Unison, or want to put it in your system, please visit:


- Adrian Bahne, Product Manager Automotive at Dirac Research

P.S. I used 13 song and album titles from some of my favorite records throughout this blogpost, can you find them all?