changing the audio world, one system at a time .... church sound, video and lights

How Important is it to Aim Speakers?

I just finished correcting a problem at the St Joseph’s Catholic Church in Issaquah. The problem was a very reverberant space with lots of echo. In the sanctuary there wasn’t a lot sound absorbing materials, tile floors, plaster walls in a basic rectangular shaped room. The 4 speakers providing sound to the 4 seating areas were located in the skylight structure. see pics

southwest cornerfrom the southwest corner beside drumsfrom the drums to the oppisite side

As you can see, the pews don’t even have any padding to help with absorption. They did have a fairly good system in place as far as the equipment rack so it was time to check out the speakers. The speakers were a Peavey 2-way cabinet with a10” woofer and a 1” tweet horn loaded. The speaker could not be orientated in the horizontal so the installer removed the horn from the cabinet and sealed the opening and placed the horn beside the cabinet see pics.... Also I put my laser on the front of the horn to see where it was pointing see pic... So basically they are pointing at the ceiling. (The angels are great sound.)

speaker orientationwhere speaker is aimed - laser line

This is not the way speakers are to be installed. The right thing here would be to install a horizontally orientated cabinet, like the ISP LT1 cabinet, this way the full frequency is projected to the seating area. The LT1 speakers would actually fit the opening. We decided to re-aim the horn for now.
Here is a close up after I re aimed the horn. I had to put a 45 degree angle down and center over the seating area. The church can now decide if they want to replace the speakers (to improve the sound system) because they can actually hear the frequencies above 1200Hz directly now.

speaker re-aim

Another problem I run into a lot is the speaker system set up on poles. Here is the way a lot of churches run their systems. Now this kind of looks like it would work but what is happening is you end up putting more direct sound above peoples heads and onto the back wall and ceiling (which is usually have very reflective surfaces) which again cause echo problems.

Old All Saint System

Its best to get the speakers off the poles, up a little bit and pointing down onto the seating area and keeping sound off the back wall and ceiling like so....

New ISP HDM115 in right locationSide shot of ISP HDM115 in right location and aimed correctly

Hope this helps. Once you’ve corrected the aiming problem it will be time to look at wiring.

Tom signing off.

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