Wave/Pressure Flow question

[johninCR]

I'm in the process of building a prototype of a horn and
I need to split the pathway in two immediately after a
fold as pictured below. My question is, will this divide
the pressure/wave flow into equal parts, or will the fold
itself create an unequal flow? It seems that more would
flow via the upward route, like water flowing through a
bend in a river, but I've never taken a fluid dynamics
class to know the physics involved.

[Svante]

For low frequencies, ie when the wavelength is much larger than the diameter of the ducts, the flow will be divided in two equal parts, provided that the two "mouth" channels are identical all the way to the surrounding air.

Note: Typically it is wrong to think of the sound waves in a duct as a stream of air; a stream of air assumes turbulent flow, and that is not the case in loudspeakers, unless they are overloaded.