SuperCollider/Schroeder 混响中的声音设计

图 14.28：循环 Schroeder 混响

首先启动服务器，如果你还没有启动的话

s.boot;

然后，为了获得一些源素材，我们将加载 SC 附带的标准声音文件

b = Buffer.read(s, "sounds/a11wlk01-44_1.aiff");
// Hear it raw:
b.play

现在，这段代码在一个单独的合成器中创建混响，并有四条独立的延迟线相互交叉交叉

(
Ndef(\verb, {	
	var input, output, delrd, sig, deltimes;
	
	// Choose which sort of input you want by (un)commenting these lines:
	input = Pan2.ar(PlayBuf.ar(1, b, loop: 0), -0.5); // buffer playback, panned halfway left
	//input = SoundIn.ar([0,1]); // TAKE CARE of feedback - use headphones
	//input = Dust2.ar([0.1, 0.01]); // Occasional clicks
	
	// Read our 4-channel delayed signals back from the feedback loop
	delrd = LocalIn.ar(4);
	
	// This will be our eventual output, which will also be recirculated
	output = input + delrd[[0,1]];
	
	// Cross-fertilise the four delay lines with each other:
	sig = [output[0]+output[1], output[0]-output[1], delrd[2]+delrd[3], delrd[2]-delrd[3]];
	sig = [sig[0]+sig[2], sig[1]+sig[3], sig[0]-sig[2], sig[1]-sig[3]];
	// Attenutate the delayed signals so they decay:
	sig = sig * [0.4, 0.37, 0.333, 0.3];
	
	// Here we give delay times in milliseconds, convert to seconds,
	// then compensate with ControlDur for the one-block delay
	// which is always introduced when using the LocalIn/Out fdbk loop
	deltimes = [101, 143, 165, 177] * 0.001 - ControlDur.ir;
	
	// Apply the delays and send the signals into the feedback loop
	LocalOut.ar(DelayC.ar(sig, deltimes, deltimes));
	
	// Now let's hear it:
	output
	
}).play
)

这里还有另一种完成同样事情的方法，这次使用矩阵来表示延迟流的交叉混合。单个矩阵取代了所有这些加号和减号，因此它是表示混合的一种简洁方法 - 看看哪种对你来说最易读。

(
Ndef(\verb, {	
	var input, output, delrd, sig, deltimes;
	
	// Choose which sort of input you want by (un)commenting these lines:
	input = Pan2.ar(PlayBuf.ar(1, b, loop: 0), -0.5); // buffer playback, panned halfway left
	//input = SoundIn.ar([0,1]); // TAKE CARE of feedback - use headphones
	//input = Dust2.ar([0.1, 0.01]); // Occasional clicks
	
	// Read our 4-channel delayed signals back from the feedback loop
	delrd = LocalIn.ar(4);
	
	// This will be our eventual output, which will also be recirculated
	output = input + delrd[[0,1]];
	
	sig = output ++ delrd[[2,3]];
	// Cross-fertilise the four delay lines with each other:
	sig = ([ [1, 1, 1, 1],
	 [1, -1, 1, -1],
	 [1, 1, -1, -1],
	 [1, -1, -1, 1]] * sig).sum;
	// Attenutate the delayed signals so they decay:
	sig = sig * [0.4, 0.37, 0.333, 0.3];
	
	// Here we give delay times in milliseconds, convert to seconds,
	// then compensate with ControlDur for the one-block delay
	// which is always introduced when using the LocalIn/Out fdbk loop
	deltimes = [101, 143, 165, 177] * 0.001 - ControlDur.ir;
	
	// Apply the delays and send the signals into the feedback loop
	LocalOut.ar(DelayC.ar(sig, deltimes, deltimes));
	
	// Now let's hear it:
	output
	
}).play
)

// To stop it:
Ndef(\verb).free;