Oct 1, 2001 12:00 PM
Another Engineers' Must-Read
The article “Keeping It Quiet: Zen and the Art of Grounding Residential Entertainment Systems” (August 2001) has joined my collection of must-read items for colleagues. I am a 20-year veteran in TV production and broadcast engineering and have been an avid reader of S&VC since the mid-1980s. Your publication has always provided me with accurate and timely information and ideas, and your advertisements have given me many installation ideas that I have specified and implemented over the years.
Another article that I always recommend to colleagues is “Grounding and Shielding for Sound and Video” (September 1995). This manual is the single most definitive guide I have seen for explaining grounding strategies for audio and video. I have given copies of this manual to electrical contractors and consultants at least a half-dozen times in lieu of trying to explain the electrical and grounding needs of A/V production facilities. I have seen many a newbie technician or engineer get that wide-eyed, “Eureka!” look when reading the manual.
In broadcast production facilities of the past, careful attention was paid to ensuring an isolated ground for a production equipment plant. As facilities have grown, and more production platforms can occupy desk-tops, most using unbalanced RCA connectors for audio, maintaining the isolated grounding system has proven next to impossible. We are having to mix and match our balanced (+4dBm) and unbalanced (-10dBm) sources and destinations more than ever before, sometimes at distances over 200 feet. This can cause a grounding and hum-creating nightmare. Obviously, balanced audio is the ideal way to prevent noise and interference, but many manufacturers seem to choose unbalanced audio these days.
assistant chief engineer,
New England Cable News
Sound on a Budget
Can you assist me with some information on how to build an isolation sound booth with not much money. I've been looking around the Web for articles but haven't had much luck.
The Editor Responds:
There are some great TAB books that you can find at your local library, electronics supply store, electronics bookstore or online book source. The first author that comes to mind is F. Alton Everest. He has written at least two books on the subject including How to Build a Small Budget Recording Studio from Scratch and Sound Studio Construction on a Budget. These should have exactly what you're looking for. You might also try a company in Los Angeles called OP-Amp Technical Books (800-468-4322). Good luck, and happy building.
Send your comments to Nathaniel Hecht, 6400 Hollis Street, Suite 12, Emeryville, CA 94608; or via e-mail firstname.lastname@example.org.