Room/wall treatments for new basement?

I would consult with the people at www.echobusters.com. The echo busters people supply materials to the professional trade not just to home audio. They will be happy to consult in your project. Give them a call

Good luck

Many of us have written extensive threads here and I would suggest doing a search. You will find a wealth of opinions.

Jeff: Drywall standard construction turns out to be excellent. If the room dimensions are right then you can do a 2 or 3 layer buildup. If not, you are actually going to want to lose some bass energy, so stick to single layer in that case. As to the "egg crate" foam. Most of that is very low density and not as good as the higher density Sonex, or even better is Owens Corning 703 fiber board wrapped in fabric.

You might want to get a book on Acoustics--Alton Everest Master Handbook of Acoustics is a good start. Our website and in particular, the listening room may prove to be helpful. The simulator there is also pretty fun when modelling a room.

I just finished the drywall in my basement, and after consulting with several "experts", I did the following:
1-Had someone that was qualfied look at my floor plan to evaluate resonance points and head off bad room layout before it was set in stone.
2-Ran truly dedicated power for my stereo from panel.
3-Densly packed my floor joists/ceiling with fiberglass insulation.
4-Wrapped all water pipes in 1/8" neoprene rubber to kill any sounds of running water.
5-Lightly insulated walls with backed fiberglass insulation to kill any resonance inside walls

The only thing I wish I had done so far but didn't is install metal strips available at Hm Depot to decouple dry wall from the floor joists above. All told, I spent about $500 on insulation, $60 on rubber, $20 on electrical, and every ounce of patience I had on my "experts".

Packed fiberglass insulation or neoprene should quiet noisy ducts depending on the amount of space you have around them (Fiberglass takes 2-3 inches, neoprene <1").