Multichannel + mono

In the example ,var a =dust ,is left channel only
B=Sinosc is an array , this left+right
Adding a+b , dust is now also on botch channels
How come ?
Is is becasue dust is added to each element in the array , [sineleft,sineright]+dust=[sineleftdust,sinerightdust]

////
(
{
   a=Dust.ar(1000)*0.5;
   b=SinOsc.ar(110)!2; 
   a+b;
   
}.play
)
////	
   

Yes, you could use the following way if you want to add dust only to the left channel:

(
{
	a=Dust.ar(1000)*0.5;
	b=SinOsc.ar(110)!2 * 0.01;
	[a, 0] + b
	// [a, DC.ar(0)] + b // this also works.
}.play
)

I want to mix them using Pan2.ar or SelectX.ar rather than the way above.