Here is something I found on the web.
HOW TO BUILD A VOCAL BOOTH FOR UNDER $300
When I was in the begining stages of getting my studio going, I started looking for prices on professional sound proofing equipment. The prices were outrageous and far beyond my budget. So through asking many experienced players in the recording business, I came up with the following solution:
Go to a store that sells rubber - eg. Clark Rubber - and buy the biggest bag of foam/rubber offcuts. It will cost you no more than $30.
Go to a hardware house that sells timber etc, and buy 4 pieces of MDF with the dimensions of:
180cm high
150cm wide
1cm thick
You can get the wood cut to size at the hardware joint. It usually costs around $1 per cut.
Then buy 8 slats of timber with the dimensions of:
180cm long
4 cm wide
2 cm thick
Buy another 8 slats of timber with the dimensions of.
146 cm long
4cm wide
2cm thick
Buy a tub of screws about 4cm long
Buy a tub of Selleys Quick Grip
Buy 9 door hinges about 5cm in height
So, by the end of your purchasing, you should have:
Foam Offcuts
4 x 180cm x150cm x 1cm sheets of MDF
8 x 180cm x 4cm x 2cm slats of timber
8 x 146cm x 4cm x 2cm slats of timber
1 x tub of screws
1 x tub of Selleys Quick Grip
9 x 5cm door hinges
Now comes the fun part.. the construction.....
Lay out a sheet of your MDF. Place one of the 180cm slats on top of the MDF's edge so the 2cm side is sitting on the MDF, leaving the slat sitting 4cm high on top of the MDF. Put the other 180cm slat on the other edge of the sheet in the same format. Screw the slats onto the MDF. Take the 146cm slats and put them on the other edges of the MDF in the same format of the 180cm slats. Then screw them in. You should then have a sheet of MDF with a frame sitting 4cm high on top of the MDF.
Repeat this for the other 3 sheets of MDF
Then get your bag of foam offcuts and cut them into random shaped blocks that sit no higher than 4cm. You will need to cut up alot of foam pieces. The randomer the shape the better. Once you think you have enough foam to cover the 4 panels, you can stop.
Get your quick grip and smother it all over the inside of the frame on the MDF. Then start sticking the foam pieces randomly all over the MDF. You will need to hold the pieces firmly on the MDF to ensure they stick. Once you have fully covered the MDF sheet, leave it overnight. Repeat this for the other 4 panels.
After letting the foam sit overnight, you now need to attach the four pieces with the door hinges. You will need to use 3 door hinges per connection. We will now call the 4 MDF sheets 1, 2, 3 & 4. Attach three door hinges connecting the backs(the sides with no foam) of MDF sheets 1 + 2 along the 180cm sides. This will mean the 2 sheets can fold back to back on the door hinges. Repeat that with sheets 3 + 4. Attach 3 door hinges to the timber slats along the 180 sides of sheets 2 + 3. Once you have done this, you should be able to fold the booth like this: The back of MDF sheet 1 folds onto the back of MDF sheet 2. The front(the side with the foam) of MDF sheet 2 should fold onto the front of MDF sheet 3. The back of MDF sheet 3 should fold onto the back of MDF sheet 4. This will leave the booth compact and ready to be moved into storage or moved around your house.
When you fold all the pieces out, you need to move them into the formation of a square. When placed in that position, you should then have a 150cm square vocal booth!
For better results, drape a thick blanket over the top of the booth to reduce outside noise getting in.
