7.3.07

Forum Week 1 - Semester 1

posted by Daniel Murtagh @ 22:22 Comments: 1

CC Week 1 - SuperCollider

[1] Create a function that takes two arguments - pitch class and octave number - and produces the corresponding the MIDI note number. [2] Create a function that can convert the pitch class and octave number into its corresponding MIDI Note number and then into its corresponding frequency. It will include extensive commenting, descriptive arguments and variable names, default values including a set tuning frequency.

Here is a SuperCollider patch I created to convert Pitch and Octave class to MIDI note number. The resultant MIDI note number is then converted to a Frequency value. Unfortunately my HTML coding skills are about as good as my SuperColliding skills, so the formatting leaves a lot to be desired.

(
// build a table of note names

var table = ();

value
{
var semitones = [0, 2, 4, 5, 7, 9, 11];
var naturalNoteNames = ["c", "d", "e", "f", "g", "a", "b"];



(0..9).do
{
arg o;

naturalNoteNames.do
{

arg c, i;

var n = (o + 1) * 12 + semitones[i];

table[(c ++ o).asSymbol] = n; table[(c ++ "s" ++ o).asSymbol] = n + 1; //determine sharp
table[(c ++ "ss" ++ o).asSymbol] = n + 2; //determine double sharp
table[(c ++ "b" ++ o).asSymbol] = n - 1; //determine flat
table[(c ++ "bb" ++ o).asSymbol] = n - 2; //determine double flat

};
};
};


a = table.atAll(#[a4]).postln; // Creates MIDI Note number

a = 2**((a-69)/12) *440; //Coverts MIDI note number to frequency value

)


__________
[1] Christian Haines. "Creative Computing: Semester 1, Week 1. Introduction." Lecture presented at EMU, University of Adelaide, South Australia, 1st March 2007.

posted by Daniel Murtagh @ 18:44 Comments: 1

5.3.07

AA Week 1 - Stereo Micing

This week we examined various stereo micing techniques. For this exercise I decided to implement the techniques for drum overheads. It seemed to me the most practical application aside from micing an orchestral performance, however I was promptly informed by peter that taking mics walkabout from level 5 was a definite no-no. So instead of soothing the savage beast with the gentle ambience of elder hall, you are going to have to deal with my less than satisfactory drumming skills. I have tried a variety of mic placements, each yielding a significantly different result;

Coincident Pair [mp3]


This example was recorded using a matched pair of NT5's. The stereo spread here seems to be quite narrow, with the kick and snare drums sounding quite resonant in the center.

Spaced Coincident Pair [mp3]


In this example I adjusted the Coincident Pair so that the diaphragms were no longer aligned at 90 degrees. As you can see from the diagram the pair is now spaced with their diaphragms aligned on a horizontal plane. The stereo spread here appears to be a little wider compared with the previous example. This is most noticeable when toms move from left to right as my drum fill progresses.

Spaced Pair [mp3]
This example demonstrated a much more "spacey" effect. Kick is not so centered, the stereo spread is a lot wider, and the reverberation and ambience from EMU's live room becomes much more apparent.

NT4 Stereo Mic [mp3]
The NT4 is a specialized microphone, which actually has two diaphragms set on top of each other in a permanent X/Y position, otherwise known as a Coincident Pair. This example appears to me to have quite a narrow stereo spread. The kick drums sounds less prominent that in the first example which uses the same technique with two microphones. The snare drum in this example has more presence than the others, this could be due to placement rather than differring mic models.

This was an interesting exercise, one which I hope to further in the coming weeks' lectures on drum mic placement.

__________
David Grice. "Audio Arts: Semester 1, Week 1. Multi Micing." Lecture presented at the Electronic Music Unit, University of Adelaide, South Australia, 27/02/2007.

posted by Daniel Murtagh @ 12:33 Comments: 1