Eddie,
When we moved into our house in 1992 I converted a large family room on the first floor into a home studio. I ordered 3" thick acoustic foam. It cost a few hundred dollars then. Now it would cost over a grand. I had to use adhesive to attach it to the walls. I covered everything except 2 windows which were double pane.

My main concern was not just having a quiet environment for myself with no sound from outside traffic, but also that no sound left my house and disturbed my neighbors.

After I finished it if I stood over 4-5 feet away from my house you could not hear anything from my studio. I put music on at a very loud level and you could not hear it out side.

The construction of it was fun. It was like a puzzle. Not unlike putting up a drop ceiling. A large expense was getting a large solid core door. I had to have someone install it. It weighed a ton.

I thought the foam was going to be a bear to cut and piece together but it was a breeze. All you need is an Electric Knife, a ruler, a Sharpie maker and a long straight edge. The electric knife cuts the foam super clean and straight.

Years ago my band used egg carbons and I never heard any difference. But it was a small room.
My home studio was a very large room and when the foam was up, just walking into the room was startling. It was so dead. Everyone had to get used to hearing their voice with no reflections. It was very strange in the beginning. But later the fact that I could go downstairs and play and record at any hour and not disturb anyone in my house was amazing. If I couldn't sleep I could play any hour of the day or night.

The isolation was wonderful. I got my best ideas and recordings, being so isolated right in my own home. The studio was torn out after a flood in 2006. All the sheetrock had to be replaced anyway because of the flood. Also because there was no way to get the adhesive off the walls so floor to ceiling replacing.

I know I didn't answer your question but I thought I'd tell you my one experience with a home studio. I could be home playing and singing at normal volume and my wife didn’t even know. It was something else.

Wayne,