Opera - Acoustics

Aim for a sound-rating in balance with the acoustics of the surrounding structure.
Even with a perfect operable wall, sound will still seep through ceilings, carpets, airconditioning ducts etc.

Control peripheral leakage around the operable wall.
For example, baffling above the ceiling will do a lot to improve the overall performance of the installation.

Similar activities require less sound isolation than a quiet activity next to a noisy one.
Amplified sound is more difficult to suppress. General background noise helps reduce distraction.

Avoid specifying far higher ratings than needed.
High R_W ratings add cost. See 'Laboratory vs Real Life'.

Don't get hung up over one or two decibels (dB).
Some manu­facturers play a numbers game. The human ear can't discern a 2dB difference, and even laboratory results can vary by 1dB depending on the conditions.

Beware of American results.
They can be 10% higher than tougher Australian testing. Also be aware the R_W is a more stringent measurement than simple speech frequency averages.

Ensure test results are reasonably recent and are from reputable laboratories like the Royal Melbourne Institute of Technology (RMIT) or CSIRO.
Laboratories with non-standard testing protocols do exist both in Australia and overseas.

Thin light panels are unlikely to be as effective as thicker heavier panels.
There is no magic to acoustic performance and weight is a key factor. Check the test reports to be certain.

It's very good and it's been done at RMIT, one of Australia's leading laboratories, to Australian Standard AS/NZS ISO 717.1-2004, which makes Lotus walls BCA compliant.

In tests up to R_W 53 we use sweep seals at the top and bottom of the panels, demonstrating that retractable seals are not required for acoustic reasons for anything other than the highest rating.

Lotus offer R_W 37 to R_W 55, which allows us to meet your acoustic requirements from budget to high performance and everything in between. R_W 55 is the highest result achieved for an operable wall in an Australian test.

The performance of an operable wall is measured in a laboratory and expressed by its Weighted Sound Reduction Index (R_W). The single R_W figure is a composite rating of sound reduction at frequencies from 100 Hertz (Hz) to 5000 Hz, when compared to an Australian Standard line.

Note that 'Weighted Sound Reduction' (R_W) was known as 'Sound Transmission Class' (STC). Numerical values are comparable. Please note that the unit of the Weighted Sound Reduction Index is decibel (dB).

Acousticians measure the performance of an operable wall in laboratories (Lab R_W). In real life even a perfectly installed wall is unlikely to perform as well due to deficiencies of the building. Buildings inevitably have peripheral leakage through airconditioning ducts, carpets, ceiling tiles etc. which can reduce the field performance by about 15%.

Be aware of this when specifying. In critical situations the surrounding walls, floor and ceiling should have an R_W rating of 6 to 10 decibel (dB) higher than the operable wall. Please contact Lotus if you need advice.