Home studio space questions...

Is this going to be a recording studio for miking things (instruments or vocals) or is it a control room? It's best to keep the two separated because your equipment will probably be too noisy to sit in the room with the microphone(s).

For a recording room I'd go with one that you can seal shut.

If you're not using a mic then that's cool.

Both big and small rooms will work. I guess you'd want to choose the one that sounds best for your purposes. Walk around the room clapping your hands and listen for the reverberance, pitch and the tone of the room and see what you like and what you don't like. From there, based on what you heard you can tune the room with combinations of insulators and reflective surfaces.

It all depends on what you're going to be using it for. You don't have to do all this stuff just to write music and record demo quality tracks.

I'm starting to read a bit about psychoacoustics and room analysis for the studio I plan to build in 2009. What I have currently is not capable of professional quality because I don't have a good studio. And by the way, the word "studio" refers to the isolated room where microphones are locatated for recording. The control room is not the studio, it's the control room. You do not tune a studio room like you tune a control room. Studios are tuned for recording while control rooms are tuned for monitoring.

If your vocals still sound bad, you can easily improve them by using some fx unit. You can also add some reverb or echo later with your dedicated recording software, but it's way better to actually hear what what's happening in realtime.

The advantage is that you can get decent reverb units very cheaply via ebay these days because everybody uses vsts these days.

I record stuff in my living room, too and I found that adding fx on the pc is not very intuitive. Then a friend of mine convinced me that hardware is sometimes the better solution and can make up for bad-sounding rooms very easily.