Can pipe joints cause water flow noise?

[reasen]

The picture shows the diverter valve for my roman tub. When feeding the tub spout, the pipes generate LOUD rushing water noise, heard throughout the house. When set to the hand spray, nice and quiet flow. Notice the multiple 90-degree bends in the line to spout. Could they be causing the noise? Is it obvious why the plumber didn't make a straighter run to the spout? Would a straighter run reduce the noise? Can the unused outlet on the diverter be used for spout? Can 3/4 inch copper tubing be used? This is all new construction and plumbing.

[hj]

1. ALL diverter valves specify that ANY unused openings should not be capped, but are supposed to be tied into one of the active device lines.
2. Probably because of the angles required, although 45 elbows would have been better.
3. The spout is not flow restricted so it can flow as much water as the valves can produce. That is what creates the noise. The shower is restricted to about 2 1/2 gpm and cannot create the flow necessary to make the noise.