by TC Furlong
On May 16, 50 sound professionals from all backgrounds converged at our first ever System Design Workshop, featuring sound system design and alignment guru, Bob McCarthy, for an intense and entertaining day of education.
It’s difficult to fit everything Bob has to offer into a month, let alone an eight-hour day, but Bob did a masterful job at conveying the main considerations when designing a loudspeaker system.
Here are three of the most important concepts covered:
F.A.R – Forward Aspect Ratio
The coverage pattern of a loudspeaker is often mistakenly thought of as a triangle or a “pizza slice”.
In his book, Sound System Design and Alignment, Bob goes into great detail about thinking of the coverage area that a loudspeaker provides as a rectangle. That rectangle has an aspect ratio and it’s based on the shape of the “balloon” that the loudspeaker creates.
The days of putting pizza slices next to each other are long gone.
Order for tuning and aligning subsystems
Here’s the method. In order of system size starting with A being the largest: Tune A, then tune B, then tune A+B, then tune C, add C to AB and crossover BC…etc.
Understanding this way of integrating subsystems is very effective.
Bob, in his unique style, says, First make Papa Bear happy, then make Mama Bear happy, then marry Papa Bear and Mama Bear, then make Baby Bear happy, then add Baby Bear to it’s mom and dad. I think this is a great way to remember how this works!
Unity Line and Limit Line for Uncoupled Arrays
Using the Lundbergh Calculator, we can now know the optimal spacing for uncoupled arrays such as front fills.
We can easily calculate the Unity Line (front row) and the Limit Line (furthest row the uncoupled array will serve).
You can read about this in one of Bob’s blog posts.
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I hope that we are able to bring Bob back soon to teach another wonderful seminar.
Please let us know if you’d be interested in attending another seminar and what you’d like to explore with guru Bob.
If you need any help with system design, tuning, or optimization, please don’t hesitate to give us a call at 847.367.9588.