BIM's Window of Opportunity
With a major building information modeling platform embracing acoustics and more, the time is right to build new bridges between AV and architecture. AV consultant Thom Mullins, CTS, explains what it will take.
Companies that create modeling software for acoustics and sound systems must find ways to make their software compatible across the breadth of building information modeling (BIM) platforms available today. That way data can be easily imported and exported with minimal fuss. Oh, and video projector and display manufacturers need to work with screen vendors to create computer models that yield the video equivalent of what we find in acoustics and sound system modeling. And make them compatible across BIM platforms.
There, I said it. Feels good to get that off my chest.
Why the declaration? Because BIM folks are getting hip to what AV pros are expert at. Autodesk recently enabled integration of a software module it acquired called Ecotect into its popular Revit BIM platform. Ecotect allows designers to model and analyze shading, lighting, thermal properties, airflow--and acoustics.
Granted, the acoustics portion only really covers reverberation time, ray tracing, and decay times using animations that are reminiscent of what you might find in EASE or Bose Modeler. It does look a little easier to move surfaces around so you can quickly see how those changes affect dispersion, but that's about it. And I haven't been able to find a Revit dealer in my area who either understands the assumptions behind the acoustic modeling in Ecotect or has any idea how to use it.
Welcome to Our World
But with Revit, Ecotect, and other BIM programs, the construction design industry is in the initial stages of an iterative process that bounces between prediction and reality. Our ability to predict how a building or room will turn out depends on how well we measure things, how much we understand about what we measure, how we measure, how we interpret measurements, and how we modify our designs going forward as a result of those measurements.
In the AV world, the tools we have now--EASE, Bose Modeler, CATT Acoustic, etc.--still provide better and more detailed acoustical information than Ecotect. They allow us to examine impulse responses, speech, and musical clarity, and help us convolve dry signal sources with the impulse response and auralize a space so that an architect or an owner can get a sense of what it will sound like once built.
The accuracy of our models is only as good as our last set of measurements and our ability to interpret and apply them to the next model. We started out thinking all we had to do was model one-quarter or one-half of the coverage pattern of a loudspeaker and that 10-degree increments would provide more than enough information. But as we measured rooms and systems that we'd modeled, we discovered some very significant differences that weren't accounted for under those assumptions. As a result, we've broken the 5-degree barrier and at least one manufacturer peforms measurements of its devices in 1-degree increments-across the entire sphere of coverage.
We've also learned how to ask good questions about the data coming from our measurements. Problems we heard, almost at an intuitive level, we are now able to understand with a better sense of cause and effect. This has lead to better rooms, better devices, better systems, and better measurement.
Some people ask, "How much detail is necessary when modeling the physical characteristics of a room?" In AV, we've learned how much detail is enough, and now's the time to share that with our companions in the design field who are starting to deal with such issues in BIM and products like Ecotect.