How We Reduced Reverb Time by 40% in Lighthouse School's Multipurpose Room
Lighthouse School | Madison, WI
The Challenge
A Brand New Room That Nobody Could Use
During a building expansion, Lighthouse School added a new multipurpose room — but unfortunately, the space was acoustically problematic from day one. With bare drywall, a brick wall, cement floors, and an open metal ceiling, nearly every surface in the room reflected sound rather than absorbing it. The result was extreme reverberation, making the room difficult to use for its intended purposes of speech and music.
In practical terms, when someone spoke at the front of the room, their words bounced off every hard surface before reaching listeners — arriving as overlapping echoes rather than clear speech. For a school, this wasn't just an inconvenience. It made the room genuinely hard to use for instruction, presentations, and performances.
Before beginning any work, Production Studio 29 measured the room's reverberation time — the technical measure of how long sound lingers in a space — to establish a baseline and guide the treatment plan.
What We Measured
Why Reverberation Time Matters in a School Setting
Reverberation time (RT60) measures the time in seconds it takes for sound to decay by 60dB after the source stops. For speech intelligibility, a well-treated room typically targets under 1.5 seconds. Music spaces can tolerate slightly more, but the goal is always a controlled, predictable environment.
Lighthouse School's new multipurpose room measured 2.97 seconds at 2kHz — nearly double what is considered acceptable for a speech environment. In a room this reverberant, a single spoken sentence was still heard after the next one began.
The Solution
A Two-Phase Approach to Taming the Sound
-
Baseline measurement. Production Studio 29 conducted a full RT60 measurement of the untreated room to quantify the problem and determine how much absorption was needed and where.
-
Ceiling baffles. 100 acoustical baffles were installed in the open metal ceiling — the largest single source of reflection in the room. Suspended baffles are highly effective in rooms with hard, open ceilings because they add absorption without requiring wall space or altering the room's function.
-
Wall panels. 13 acoustical panels, each 6 feet tall by 2 feet wide and 2 inches thick, were installed on the brick wall. Brick is one of the most reflective surfaces in a room, and targeted panel placement brought the remaining reverberation under control.
-
Post-treatment measurement. A second RT60 measurement confirmed the results and documented the improvement for the school's records.
Before & After
See and Hear the Difference
Before
After
Before
After
The Results
40% Less Reverberation — and a Room That Finally Works
The combination of ceiling baffles and wall panels reduced the room's reverberation time by approximately 40% — from 2.97 seconds down to 1.76 seconds. The improvement was immediately noticeable. Speech intelligibility increased dramatically, and the room became genuinely functional for its intended uses for the first time since the expansion was completed.
The before-and-after difference is audible — not just measurable. You can hear it in the video comparison below.
Before
After
Is Your Space Struggling With the Same Problem?
Most Hard-Surface Rooms Can Be Fixed Faster Than You Think
Hard surfaces, open ceilings, and large empty rooms are common in schools, churches, and commercial buildings — and they create the same issues every time. If your staff or congregation is straining to hear clearly, or if your meeting room feels like it's working against you, acoustical treatment is often a faster and more affordable solution than people expect.
We offer free consultations for acoustical treatment projects throughout Dane County and Wisconsin.