Sunday, July 22, 2007

INTO THE CONTRA PROJECT

I've been in Sydney for three weeks now, and the time has absolutely flown by. In the first week, we worked on getting software uploaded onto my computer, getting recording hardware set up and functioning correctly, and the interface between software and hardware all running smoothly. The fact that we wanted really accurate and faithful sound recording down past 30Hz really posed some challenges, and we used up a couple of days getting a system set up that we were happy with. I had to learn how to run the recording system, including the computer with the recording program, and do the checks needed to maintain consistency from session to session.

In the second week I did the series of recording sessions to record the samples I wanted to be able to analyze. Along with that came the process of creating the filing system for the sound files, so that I could always find any sample I wanted, and that each sample extracted had its unique reference to the entire session built into its file name. In between recording sessions and maintaining the log book, I got started using the special program that John Smith, a Professor in the Physics department at UNSW, wrote for the specific analysis I wanted to do on the note transients.

The recording room is a specially sound-deadened room that is designed to not reflect any sound waves. Needless to say, it is a dead room to play in. I call it "The Room of Truth". While I was doing my recording sessions, I was trading off time in the Room of Truth with Jer Ming, a grad student and teaching assistant, who is doing a big project on the saxophone. The first picture shows Joe Wolfe playing the sax during one of those sessions. My contra is taking a rest, waiting for the next run of tests.


By last weekend I had finished the recordings and had started working with the samples. John Smith came back from his semester break last Monday and I met with him to show him the progress I had made with his program. I also asked if he could make it do a couple of other things I had in mind, and he came back with a version 2 of it. Then this past week, we got set up to do the impedance tests on my instrument. There was a lot that actually went into being able to do the impedance tests, and it all came together fairly smothly. There were only two problems to deal with along the way, once we got set up, and the solutions to each one came within a couple of hours.



This picture shows the contra all set up in its special bracket, with the impedance head attached. It is specially calibrated, and is attached to a prepared bocal. Since the impedance head had a limited number of sizes of openings available, we sawed off the end of a bocal at the point where its diameter would mate with the impedance head, so there would not be a discontinuity of bore between the two. The missing part of the bocal will be added back in to the impedance curves mathematically. Then the compliance of the reed will be added in. Don't ask me how that is done! The explanation of that goes right over my head.
Towards the end of this past week, John Smith came back to me with the fourth version of the Mathematica program he has developed for this project, and now it has been developed about as far as it can go. So now we already have a lot of data collected, and have tools in place to do the analysis I (and we) want to do. Next we do another round of tests on a standard contrabassoon, to have another set of data to compare to.



The first weekend I was here, Joe Wolfe took me out sailing on Sydney harbor, and it was a special treat to have my first glimpse of the Sydney Harbor Bridge and the Opera House from a small sailboat out in the harbor.