I’ve taken the trig for designing uncoupled loudspeaker arrays and made it into its own piece of software. It is a big UI improvement over the old Excel sheet, it draws a diagram of the array, and it can export arrays as XML files for Meyer’s MAPP Online Pro. It’s written in Python, but I’ve created standalone versions for both Mac and PC.
One of the best ways to understand sound waves and phase, and how we apply them to live audio, is to see signals interact in real time on an analyzer screen while listening. This is exactly what the Meyer seminars to which I’ve been have done; the instructor sends pink noise into a DSP, has the outputs of the DSP go into a console where they can be summed, and then has the output of the console and the original noise signal go into a SIM analyzer for comparison. Attendees see the effects of summing multiple signals that differ in phase and/or amplitude, or the effects of EQs and filters, at the same time as they hear them. I’d like to share with you a simple method for having the same type of educational resource entirely inside Mac OS X – no expensive external hardware required.
It requires a dual-channel software FFT analyzer (I use SMAART 7), Apple’s AU Lab, which is a part of the developer tools package that comes with every mac, and Soundflower, a utility that allows internal routing of audio signals. I am using the signal generator inside SMAART, but you can use another program if you like. The basic routing is as follows: the signal goes into AU Lab, gets routed to several busses to which different processing can be applied and that can be summed, and goes to the measurement channel of the analyzer software where it meets up with a copy of the original signal for the transfer function. A separate output routes the processed/summed signal to the computer’s speakers so that you can listen to what you’re doing at an independent level, or not.
Update 7/19/14: You can download the newer version of the calculator here.
Bob McCarthy’s method for designing uncoupled speaker arrays can take a lot of guesswork out of using MAPP. To further streamline the process, I made a calculator that describes the relations between the parameters of speakers in uncoupled arrays.
The important parameters are the spacing of the elements (s), the splay of the elements (β), each element’s coverage (φ), the distance at which the coverage patterns of adjacent speakers overlap (D-Unity), and the distance at which three elements overlap (D-Max). For simplicity’s sake, I have made some intermediate parameters:
Update 7/14/14: I’ve posted a vertical loudspeaker aiming calculator which is a better starting point than this in most cases
One of the things on which I’ve been working of late is a formula to find the ideal speaker coverage angle for a seating area. It has involved a lot of trigonometry and double checking in MAPP, but I’ve found something which seems to work pretty well for single speaker applications and fits conveniently into an excel calculator: