And welcome to my new weekly Monday mailbag where I’m going to answer the many questions that come in via email to us so as to help out fellow home studio designers and audiophiles. I’ll be here every Monday with answers to all your latest questions. So if you’ve got something you need answered in relation to sound diffussion, home studio and theatre sound design and more then please feel free to send them into firstname.lastname@example.org.
To get us started this week I thought I’d answer this message that came in from Todd in Atlanta, Georgia.
Been reading the blog for a while now and thought you were the perfect brain to pick before I get started with my studio installation. I really want to know what’s the best bang for my buck – acoustic foam or acoustic panels?
I’m almost done installing my vocal booth. I jusy need to finish the door and window plus I need to add the insulators but my funds are running out. Would I be better off getting foams or panels? In the long run what will be the difference in the sound recordings?
It is nice to see someone taking on a vocal booth project. It is no easy task.
Window – Laminated Glass
Lets examine the window first. Always use a laminated window that has laminated glass on at least one side of your vocal booth window. A laminated window has a layer of plastic melted onto its surface and thus adhering to the glass pane itself. Remember, sound isolation technology is all about minimizing vibrations. Since you are on a budget, use 1/4″ thick laminated glass as a minimum thickness.
Position the glass into a frame and then secure the frame into the window opening. Use an acoustic sealant between the laminated glass and the window frame and also the vocal booth window opening and the frame itself. For better results, place another piece of laminated glass, 1/4″ thick, leaving a 1″ air space between both 1/4″ laminated pieces into the window frame. This dual pane method is worth the extra cost in materials, since it appears that you are doing all the labor.
Mass Layered Door
For the door, you can take two pieces of 1″ MDF or multiple density fiberboard. Make sure it is the commercial grade MDF, it will be smoother and easier to finish if you desire. on top of 1″ MDF door piece, glue a vibrational damping sheet of at least 1/8″ thickness to one of the MDF sides. Make sure there is more glue applied to the exposed damping compound. Place the second MDF piece on top of the glued damping compound. You must place an acoustic glue or sealant on both sides of the damping compound. You are making a sandwich of two – 1″ pieces of MDF with a thin slice of vibrational damping compound glued between them.
Place self tapping deck screws that are 1/1/2″ long, 12″ on center throughout the door surface area. This is a heavy door. make sure your hinges can support the weight. You will be at 10 lbs/sq.ft. Do not forget to include a heavy duty weatherstrip between all edges of the door to door frame contact ares. A small air hole is like a leak in a high pressure dam. It will leak lots of sound energy.
Inside Booth Foam
Treating the inside of your vocal booth with foam absorbing technology is the most economical way to cover the vocal frequency ranges you will be dealing with which start around 150 Hz. and go past 4,000 Hz. Make sure you choose a foam that absorbs at the proper rates and levels that are necessary for you to achieve whatever vocal sound you are going for. A closed cell foam will give you those necessary rates and levels of absorption in your vocal booth. Thicker closed cell foams will produce higher rates and levels than thinner foam of the same type. I would suggest starting with 1″ thick closed cell foam.