Technical information
Measured, and published in full
C-ATS commissioned BSRIA to measure sound absorption to BS EN ISO 354:2003. The full report and the per-panel coefficient sheets are published here, without registration.
What was tested, and how
Three materials were tested in eight configurations in a 210 m3 reverberation chamber, to BS EN ISO 354:2003, in July 2019. The figures are design stage reference values measured with panels free and unfixed, which is a laboratory mounting rather than a finished install. Where a configuration matters to the result, it is stated with the figure.
Reading the two Reflection series
The Reflection Control Panel chart plots two series, and they are the two install types rather than two versions of one figure. A panel bonded with adhesive is damped by the bond: it absorbs less and behaves as a clean scatterer, which is the condition a design assumes. A panel fixed with screws alone is free to resonate, which adds absorption the design did not allow for. Bonded is the default in the modelling tools for that reason.
Reading the Resonance figures
The Resonance Control Panel is quoted as equivalent absorption area in square metres per panel, not as a surface coefficient, and the intended configuration is three panels in corners against two walls. Those values already include the effect of corner loading, so a design tool must not apply a corner factor again. No claim is made below 125 Hz, because the report does not extend there.
Reflection Control Panel
Absorption coefficient by octave band
- Type A, adhesive-bonded (recommended; modelling default) Legacy CATS Calculator, entry 3084
- Type B, free/unfixed BSRIA test 6, plane absorber, 16 tiles, 1.44 m2, centre of room
Resonance Control Panel
Equivalent absorption area per panel, by octave band
- BSRIA test 4, three items in corners against two walls (the manufacturer's intended configuration) BSRIA Report 100241/1
Reverberation Control Panel 50
Absorption coefficient by octave band
- Plane/surface BSRIA Report 100241/1
Design-stage reference, free/unfixed mounting. Coefficients above 1.0 are normal for measured Sabine absorption.
The published data
- BSRIA test report, in fullReport
- Reflection Control Panel, absorption coefficientsData
- Resonance Control Panel, absorption coefficientsData
- Resonance Control Panel, boundary conditionData
- Reverberation Control Panel 50, absorption coefficientsData
- Marine Reflection Control Panel, absorption coefficientsData
- Reflection Control Panel datasheetDatasheet
- Reflection Control Panel dimensional drawingDrawing
- Reflection Control Panel install instructionsInstructions
These files are the authoritative published figures. They are served from the current site until they move into Engine's document store, at which point they publish and version with the products and these links are replaced.
Questions these panels raise
- Should the Reflection Control Panel be bonded or screwed?
- Bonded, and it changes the measurement. The adhesive damps the panel so it absorbs less and behaves as a clean scatterer, which is the condition a design assumes. Fixed with screws alone the panel is free to resonate and adds absorption the design did not allow for. An installer working on instinct will screw it and skip the adhesive, so it is worth stating on site rather than in a manual.
- How far from the designed position can a panel move?
- Reflection panels tolerate roughly 300 mm from the designed position without material change in performance, so the install does not need set-out precision. That tolerance does not transfer to the Resonance Control Panel: its effectiveness depends on corner placement, and it is the one panel in the range where position is not forgiving.
- Why do the absorption figures look low?
- Because the Reflection Control Panel is not an absorber. It scatters reflected energy off axis, and low absorption is the intended result rather than a shortfall. Reading it as an absorber is the misapplication to guard against.
- Can the panels sit behind a fabric finish?
- Yes. They are designed to be concealed, and any stretch-fabric system works. Fabric Walls pairs well with them and is not a dependency.
- How many panels does a room need?
- That is what the design service answers. Quantities come from modelling the room across all three problems rather than from a rule of thumb, and panels are supplied in whole boxes covering 1.44 m2, so take-off arithmetic is straightforward once the layout is set.
- Is there absorption data below 125 Hz?
- No. The BSRIA report does not extend below 125 Hz, so no claim is made there. The Resonance Control Panel is the low frequency device in the range, and its published figures already include the effect of corner loading, which means a design tool must not apply a corner factor a second time.