Here are 4 principles that ease the headaches: Use balanced circuits for long cable runs, match levels, isolate equipment electronically, and use devices with level indicators (VU meters).1. Audio cables that extend longer than 20' should be balanced circuits (Audio cables that use an RCA connector are unbalanced; audio cables that use XLR connectors are balanced). Devices like the ProCo IT-1 (www.procosound.com), OpAmp Labs (www.opamplabs.com) or Peavey 1:1 convert unbalanced audio to balanced audio, and vice-versa without affecting level. Also, Behringer makes cheap mixers with a street price of $50 that will perform this function actively for two channels, with VU meters that provide verification of levels.
2. Brent Handy's wise advice on snipping the XLR pin 1 conductor to rid hum (called "lifting the ground") notwithstanding, it doesn't hurt for equipment on different power outlets should be isolated from each other with a passive or active 1:1 transformer. Again, the 1:1 isolation devices mentioned in my first point will perform this function. Try lifting the ground; if that doesn't rid the problem, go with 1:1 iso transformers.
3. Level matching: There are essentially three levels for interfacing equipment: mic level (-60dB to -40dB), semi-pro (typically unbalanced) line level (-10dB) and pro line level (+4dB). Headphone output jacks are essentially line level, but I never use them, as they are unbalanced and will be noisier than other output jacks on the same device as well as other potential problems. Simply put, level matching is important.
I highly recommend that you use the XLR output from the sound console, as it is a balanced circuit, and probably +4dB. To match levels, you could use a dedicated active level matching devices like from Radio Design Labs (www.radiodesignlabs.com) or the aforementioned Behringer mixer, and then to the unbalanced inputs on the VCR. Both these devices are capable of converting semi-pro unbalanced line level to pro balanced line level and vice versa. Locate the interface next to the unbalanced device (VCR) and keep the unbalanced patch cord short.
4. Using a small mixer between systems balances/unbalances the circuit as required, but also gives you audio level verification with VU meters. Its a good policy to test level matching with a tone oscillator or CD with test tones that don't deviate (think "Emergency Broadcast System") . Turn off power amplifiers when you do this alignment. Zero decibel (0dB) on one analog device should match zero decibel (0dB) on the next analog device in the chain. Adjust the input device so that the two devices match.
Incidentally, hum can occur between two video devices, too. If you ever see rolling gray bars on your projector or monitor image, you probably need a video isolation transformation in the circuit. This might be a cure for the issue of the computer that generates "static".
Used by churches all over the world to help teach worship, the Experiencing Worship study can help your worship team too.
Your team will learn why we worship and gain a better understanding of how to worship.
One user said..."Your 5 week study course has made a tremendous impact on my life in the study of worship... I would like to express my thanks for a well written study course that leads into a higher realm of praise and worship."
This is the debut album by EXW friend Paul Langford. Paul is a Chicago based singer, arranger, keyboardist, producer and conductor. Paul has a career that spans 14 years. Paul's work includes arranging for groups like GLAD, Voices of Liberty, VoiceTrek, The Chicago based "Caroling Party" and Day of Discovery Singers. His arranging has appeared on recordings side by side with greats like Gene Puerling and David Maddux, and he has sung with Don Shelton, Bonnie Herman and Bob Bowker, among others.