Evan Grimes, the audio director at Highland Baptist Church, was doing an incredible job managing the sounds in the Life Center. With a Midas ProX console and L-Acoustics dv-Dosc line arrays, he had some great tools at his disposal. His mix was dialed in and he had a solid soundscape from week to week, however there were some challenges that he could not overcome. First, there was this slapback on stage driving the worship team nuts. Second, the echoes during the message made it difficult to understand what Pastor John was saying. Evan tried to address these things with stage configuration, EQ, and the mix, but was just coming up short.
While Lucid was there helping with some lighting upgrades, Evan asked Joe about it. We looked around at the classic Gym-Atorium together, and some things jumped out right away. The back wall was sheer up to 25’ and every wall was parallel. There was a fair bit of acoustic treatment, but it was up high and flat to the walls, not down low where people's ears are. The line arrays were aimed pretty high up the back wall, so when you stood on the stage and closed your eyes it felt like the arrays were pointed straight at you instead of away from you.
We talked about some options and came up with a plan together. For the slap back, we decided to treat the rear wall with two rows of acoustic diffusers. One at ear height, and one just above and with higher density where the arrays were aimed. These would break up and disperse that energy instead of reflecting it straight back on to the stage. In addition, we reviewed the speaker configuration in L-Acoustics Soundvision software and discovered that we could aim the arrays lower while still covering the room, greatly reducing the amount of energy on the rear wall. More energy on the people, less on the walls, win-win.
For the message, echoes and reflections came from all directions. We walked around and noticed that the side wall to side wall reflections were very noticeable. So, in addition to the rear wall, we decided to treat the side walls with diffuser panels as well. A row at ear height from front to back should do the trick.
Lastly, we noticed that the arrays were close up to the drop ceiling. With how much energy there is that close to the arrays, we wondered how much impact a reflection off the ceiling would have on the sound in the room. So, we decided to add some drop in diffuser ceiling tiles in front of the arrays and we would A-B test the results during tuning.
We had a plan, and we put it in motion. With lead times, there was about a 3 month wait for the acoustic diffuser panels to ship. One day, Evan called Joe as their Peavey MediaMatrix DSP was having trouble. We did some troubleshooting and ultimately decided to replace it with a Q-Sys Core. We already had budgeted for a re-tune of the PA, so swapping the DSP was an easy addition to the project. Joe flew down and swapped the DSP in on an extra trip to get the system back up and running until the acoustics came in.
It is important to tackle a project like this without impacting the normal flow of rehearsals and services. So when it came time to do the installation, Joe and his son Barrett came down on a Sunday and got to work. They had the panels up by the end of the day Tuesday leaving Wednesday for tuning. Rehearsal was Wednesday evening so we wanted to be ready to rock by then.
Joe loaded the latest firmware and presets from L-Acoustics into the LA8 amplified controllers. We also took advantage of the new Autofilter FIR feature which further smoothed out the front to back coverage of the arrays, while remaining phase linear. Side note - the speakers are 13 years old and have been discontinued for years but thanks to the L-Acoustics platform these brand new features work beautifully.
The system tuning went super smooth. The A-B test of the diffuser tiles in front of the arrays showed a significant improvement in the impulse response compared to flat tiles. When Evan came in to take a listen, he was greeted by our old friend Rick Astley.
Wow, what a difference. The Gym-Atorium no longer sounded like one. Pastor John is clear and easy to understand. The slap back on stage is gone completely. And we managed to not make the room too dead in the process. We are thankful to get to play our part, now it’s all up to you Evan!
