Questions, Suggestions & Tips: from friends and readers
Q: We are using monitor speakers on our new chancel area for our singers, and in our band area. Weve been plagued by annoying hum. Any suggestions?
Suggestion: If the hum is a low "B natural" note, youre suffering from a "60-cycle" hum. This is the frequency at which AC (alternating wall 120-volt current) changes polarity. This hum is usually evidence of equipment not being properly grounded, and/or not sharing a common ground. When the amplifier powering the monitors isnt properly connected to an appropriate ground (and there are more than one), or the receptacle box housing the monitor 1/4" jack, is connected to a different ground than the amp, AC hum may be introduced in the monitor signal. There can also be something called a "ground loop" established, which acts like a radio antenna, inducing noise and interference in the circuit. If the the problem isnt alleviated by a "ground lift switch" (often a rocker-type switch on the associated equipment, its well worth a visit from a qualified electrician or experienced sound installer to verify that your grounds are proper. Tip: Grounding is very importantfirst for safety reasonsthen for prevention of unwanted noise. Always use equipment with three-prong plugs for safety and uniformity. The rounded center plug is normally connected to "earth" ground. Never defeat the three-prong plug simply to avoid buying a proper extension cord or power cable. Sometimes use of a "3-to-2 prong" adapter removes noise by breaking a ground loop. This is evidence of a grounding problem, and should be used only as a last resort temporarily. Shock danger may existespecially between mics and an amp or keyboard with such a "bypassed" ground.
Q: Were a small church with a group of committed singers and musicians, but our equipment leaves a lot to be desired. What components should we start replacing first? Amp, mixer, speakers?
Suggestion: Without knowing your priorities, its impossible to say. Absent any other information, make sure you have adequate loudspeakers for your space and combination of preaching and musical needs and aspirations (always build in room for growth when you buy new equipment). Then, the adequacy of your power amp(s) will be determined. (See "Amp Tip" by QSCs Patrick Quilter in this issue.) In a small church you can probably get by with a 16-channel mixer there are many affordable alternatives. You may also wish to consider a combined amp and mixer unit. Good quality microphones and cables will round out your tools, assuming you have adequate musical instruments and individual amps. Tip: Sometimes people are tempted to scrimp on cables and cords when resources are precious. You dont need to have gold-plated everything, but dont be penny-wise and cut corners on decent cables and connectors. Use good balanced XLR (three-pin) mics and cables to reduce interference, and only use special high-voltage 1/4" jack speaker cables to supply signal to your monitors. Do not use a low-voltage instrument cable with the monitorseven though it has compatible 1/4" jacks. The instrument cable is designed for very low voltage and signal levels from a guitar, bass, or keyboard. The high voltages sent from a power amp to drive the monitors can damage the instrument cable, leaving it more susceptible to noise. Much time can be spent chasing down "missing" signal and isolating bad cords and cables. First, invest in spares. Second, get your team a "test box" for cables. For only about $50 you can buy a device that tests XLRs, 1/4", RCA-types, and combinations. Itll save you a lot of aggravation and system diagnosis time. Tip: Itll also pay big dividends keeping your cables neatly wound, secured with velcro ties, and stored in a predictable place. Neatness is a virtue, and will reward the "keeper of cables" many times over, by having things where theyre expected to bewhen theyre needed.
Q: In a contemporary worship format, we can and sometimes do refer to our hymnals, but usually have the congregation sing from projected lyric slides. The latter gives us a lot of freedom in structuring songs. Does it make sense to vary our newer song structures just for the sake of variety? Suggestion: Theres always a balance to keep between the familiar and the new. Our experience working in a contemporary participation format suggests that the congregation takes a while to "cement" a song into their "working repertoire." With the flexibility of tailoring lyrics for video projection, one can easily restructure participational songs any way they choose. Just remember that a change demands more effort on the congregations part than the worship teams part. The spirit of worship can be enhanced, we think, by keeping flow as "unconfusing" as possible for the congregation. Remember how great it feels to launch into singing a classic hymn like "Holy, Holy, Holy?" One reason for that joyous abandon to worship in song is love for the familiar. That same principle can also apply to newer songs. Praise the Lord!
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Christian Sound & Song, 3112 Lexington Park Drive, Elkhart, IN 46514, or fax to: 219-522-5150.