You’ve Modeled How It Looks, But How Will It Sound?

2015/10/07

By Frank Brault, Entertainment Industry Product Specialist at Vectorworks, Inc.

Whether you’re designing an indoor space for a concert venue, an auditorium, or even a large industrial, it’s important to make sure that your site looks like what the client envisions. But it’s also equally important to model what the people experiencing those spaces will be hearing. The location of the listener, the shape of the room, and the sources of the sound all impact the environment you’re creating. This is an issue that many of designers face while working in the entertainment industry, which is why I recently tested the workflow between Vectorworks Spotlight and ODEON software, an acoustics simulation program that analyzes and predicts how sound will move based on a building model.

First, I opened an existing theatre model in Spotlight that I had made for another project. ODEON’s Managing Director Claus Lynge Christensen recommended adding the necessary detail to make the room leak-proof, so I went through the model and closed up some gaps in the walls, under stairs, and behind seating risers.

Theatre model prior to export to OdeonNext, I exported my Spotlight model in STL format. ODEON works with STL files, as well as with DXF and SketchUp. Once my model was in ODEON, Claus used the Convert to Surfaces function to create the objects that ODEON uses. At first, my model had over 35,000 surfaces, which Claus noted was not optimal and could affect the accuracy of my results. After a short talk to figure out how to minimize the amount of surfaces, we realized that removing the lighting instruments in my model wouldn’t have a noticeable effect on the sound, so we turned them off and got the surface count down to an efficient number of around 5,000 surfaces.

Now, it was time to get into the sound work by setting up point sources and receivers, which indicate the origin of the sound and desired test points in various places in the room. They’re created in a similar way to how I usually place lighting devices, hanging positions, and focus points in Spotlight. And since I could set multiple receivers, I could compare the sound quality for people sitting in the orchestra with those in the balcony, which was really cool.

From there, I could start to analyze the room. ODEON has quite a few ways to explore sound, like its fascinating auralization feature, where you can upload a prerecorded sound file and hear the clip in a room’s various listening locations. Also, since ODEON can assign material properties to surfaces, you can predict the effect of various surface treatments on the anticipated sound quality. That way, you can be as accurate as possible with your room setup before you arrive onsite.

Here is an unprocessed, dry-sound sample of a cello solo before using ODEON’s auralization feature:

 

And here is the same sound sample, derived from a specific receiver position and source within the theatre test model:

 

In addition to the auralization function, ODEON calculates simulated reverberation times and can also produce many kinds of graphical representations of sound, like color diagrams based on frequency, loudness, scattering, and absorption. It can even produce graphs and charts of individual audio parameters at specific points in the room. You can use the results detailing the projected sound quality to improve your Spotlight model. Now, you can ensure your designs both look and sound their best. Learn more about ODEON on our Industry Partners page.

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