im not really encouraged to post anything asking help about anything.
Thats because you didn't bother to take time to tell us your requirements.
A booth with 30db of soundtransmission loss is totally different than one that needs 50db. So how are we supposed to know your needs?
Ok, here is the deal. I've been on the bbs 5 years. I've also replied to peoples request for how to build a vocal booth at LEAST 20 times. But the fact is, NO ONE has wanted to do what it takes to build a true isolated booth. They want CHEAP FAST TAKE NO SKILLS LITTLE ISOLATION AND PORTABLE. My reply is......bullshit. Simply put, I can tell you how but you won't like the truth.
Most people lack the understanding of isolation construction requirements and think that blankets will work just fine...
Maybe if you live in a noise vacume. But that is the problem. Everyone has a different set of criteria...either they rent and need portability with little isolation value , or intense isolation with no budget, or a good material budget but no skills or tools or the materials arn't available. Even your run of the mill carpenter or contractor doesn't have a clue to what it takes to achieve even 40 db of isolation. Especially if there are drums in an adjacent room at the same time. Which is another set of criteria. Everyone has a different way of recording too.
There are lots of people here who DO know how to build one, but it appears lately that everyone has grown tired of telling how only to get...."well, I don't think I want to do that"...or "I can't afford it"...or any number of final responses. What I suggest here is for you to do a SEARCH. If you can't find the answers by doing a little investigating yourself, then you don't want it bad enough. On the other hand, if you do find what your looking for but still have direct questions, come on back and I'll try to help you.
and putting acoustic foam on 75% of the walls. do you think will make for a good sounding vocal booth.
Possibly. Personally, I'd line the whole booth with 4" rigid fiberglass and cover with fabric. Then add ambience via electronics. But thats my .02
fitZ