Two thoughts on the subject: 1. Plumber friends insist on cast iron as the quality product. Some accuse them of only be interested in costly installations. The fact is, I lived in basement apartments in my youth and I never heard the drains from many stories above. The pipes were cast iron. Ah, the good old days before plastic. 2. Noise comes from water falling from great distance and passing through many turns and bends. The way to reduce such noise is to make short falling distances and long, gradual, straight runs. It is probably the fault of governing bodies for not requiring drain pipe tuning classes for plumbers. But these thoughts have the quality of 100% hindsight; unfortunately neither are an answer to inexpensive completion before finishing a basement for tenants.