Should You Church Accept THIS!!!!!
Recently, I went to a church where my daughter
went to sing for a school competition. It is a large beautiful
Church about 80 years old. When I looked up, I saw a speaker
cluster. In the poor light, I could not see much at first. When
the concert was over. I took the photo below.
Inserted into the photo is a close-up of the
cluster. It has two EV speakers. The system did sound good, (
Whoever, installed this system put the speakers in the sweetspot
of the room) but the real question is, would you stand under
that?
Legally, such a suspension is supposed to have a
chain backup. There is no chain or even a backup set of cables.
Here is another church. This is a 6 sided
church. The speaker cluster has 6 pictures. (This speaker system
is behind the sweetspot and tests showed a an average of 2%
increase in intelligibilty if the cluster is moved ahead 8
feet.)
This is a closeup of the speaker installation.
Would you stand under that? Again, no backup support.
A few years ago, I put up this speaker system.
There are 4 speakers. 3 for the front of the house and one for
the choir. It is all steel Bracket. This style of speaker backet
was tested years ago. At the weakest point, it takes 3000 pound
of force to breaket it. At 1200 pound the metal will bend. The
total weight of the speakers shown is under 200 pounds. The only
other weak point of the bracket is the ceiling support. The 3/4"
grade 8 bolt has a shear break point of over 2000 pounds.
The two side speakers weight 45 pounds each. The
1/2" bolt has a shear weight of over 2000 pounds. The side
arms are 1-1/2 x 3/16 flat bar and 3/8 blots with "T"
nuts are bolted to the sides of the speakers. In this example
Tannoy Speakers are shown. Each speaker in this bracket is fully
Pan and Tilt adjustable. The cost of this bracket was less than
$200.00. Each speaker had threaded rods from top to bottom, side
to side and the front face of the speaker baffle board is
slotted into the edge pieces.
Here is a low ceiling example of an all steel
bracket.
So, Which set of speakers would you like to stand under? An all steel Bracket,
A professionally rigged system that costs hundreds more or a do it yourself
cable and chain?
By Joseph De Buglio(c) JdB Sound, Acoustics, Canada Jan. 1999
If you have any questions or comments about this, please e-mail me or
post your comments on the discussion group. Thank you.
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