If i go with the speakers i'm looking at then the
impedance is 8ohms and the wattage of 250watt continuous, 500watt program, and 1000watt peak. I would run two sets of two speakers in parallel meaning the total
impedance for each
channel is 4ohms. So the first thing what wattage amp should i consider using? And then giving the
power output of that amp and a distance of about 75 feet what
gauge would i be looking at then? Also what's the difference between the three wattages the manufactures spec sheet gives me?
General:
Hello, rtbagby. My, my, my - don't you have a challenging little setup... As long as only the instrumentalists are in the band area and the vocalists are up front (altar area) there is hope. If vocalists are on the side (or if a number of vocalists are actually singing instrumentalists) then a solution becomes more of a challenge.
If stand-alone vocalists are in the band area, it would be beneficial to move (at least)
them to the altar area. If you have singing instrumentalists, it would be beneficial to move the entire lot of musicians to the altar area.
As long as the vocalists are in the altar area, you can install a traditional
speaker system which is optimized for the congregational seating area. Any vocal spill-over into the band area would be generally nondestructive (as long as your instruments are DI rather than miked acoustic) and at worst might provide more vocals to the band area than they would prefer. This would be a very workable scenario.
It would be helpful if the ceiling height up front were higher - but it is what it is. Speaking in (very) general terms, a main
speaker system flown as high as
practical over and slightly in front of the altar
platform area (as others have suggested) would serve you well and could be configured to provide acceptably even levels from front to back (especially if the front-to-back distance is really only 30'). It would be good to measure and get close to the "exact" room dimensions before finalizing a decision on
speaker system design. Could you do this?
Speaker/
Amplifier Question:
Ahhhhh... the old
speaker/amp terms struggle. In an industry in which these terms are not well standardized (sometimes not at all) and in which one manufacturer often uses the same term as another, but with altered meaning - its difficult for
anyone to decipher at times.
Generally speaking, the "continuous"
rating describes how well the
speaker can withstand long term average demands often measured by playing steady sine waves or some sort of weighted noise input. This type of signal, even at lower
power ratings, causes the
speaker to do "continuous" hard work and thus, this
power handling figure is the lowest of the three.
"Program" is typically based on a test signal that simulates "real world" music conditions - such as - perhaps - your band and vocal group. Obviously, this type of sporadic (both in amplitude and frequency) signal does not require the
speaker components to work as hard as a steady-state signal (of similar wattage) and thus the increased allowable "program" wattage figure.
"Peak" is usually based on an instantaneous
spike of signal (usually no more than 1/10 of a second), and is a signal that the manufacturer is indicating should not be exceeded without expecting damage to the
speaker (just as in the previous examples). Thus the
power handling capability is higher - but only for that brief "instance of time".
In a nutshell, the terms/ratings described above are merely ways of expressing how much
power input the
loudspeaker can withstand as it experiences different forms of amplified signal input.
Though there is no absolutely "right" amout of
power - a reasonable rule of thumb for powering a
loudspeaker is to provide
amplifier power that has a
power rating of 1.5-2.5X the
speaker's continuous
rating. More is possible with care and with proper utilization of peak limiting.
Though you could just go with 12 guage and jettison any concerns (as I probably would...), 14
gauge wire would be fine for the cable lengths you are expecting - with quality cable you should lose less than 0.5dB from amp to (
passive)
speaker.
I wish you the best on your project.
Regards,
Mark