Acoustic Expectations of an Installed Moveable Wall


If your Moveable/Operable wall is not performing up to your acoustic expectations below are some measures you can take before you contact the Supplier/Installer and/or the project design team.

Compare your personal acoustic expectations to how the wall is actually performing.

Lets assume a meeting room in an office environment. Examples of “sound” within an “office” space as measured in dB are: 50 dB – an average office, 60 dB – conversational speech & 70 dB – a noisy office. These are the 3 dB levels that you are likely seeking to maintain within your divided space. Lets assume you have an STC 50 moveable wall dividing meeting spaces. STC 50 means that the wall, in a perfect environment, will reduce the sound transmission through it by 50 dB. In the field, a “non perfect environment” the estimated dB reduction will generally be 10 points less or 40 dB. If you have adjacent meetings at a typical 60 dB and an STC 50 dividing wall, then approximately 20 dB of sound will be transmitted through the wall which will be noticeable but not disrupting. But if I have a normal conversational speech meeting at 60 dB on one side and a meeting with an amplified presentation on the other generating 90 dB of sound and divided by an STC 50 wall then 50 dB of sound will be transmitted from the high side to the lesser which will be very noticeable. In this case the wall is performing as well as it can but the STC selected is simply not high enough to meet the expectations.

The lesson is to determine beforehand the correct STC for your anticipated/predicted needs. Compare expectations to realism. The lesson is when selecting an STC for a moveable wall it is best to go too high STC than too low.

Look at the sound test for the wall you have installed.

Ensure that the wall that you have in place is the wall described in the manufacturers sound test. Look past the “number”. Some manufacturers will submit a sound test that is out of date or does not accurately describe the product that they propose to supply and you now have installed. You have that wall based on the expectation that all that will be looked at when the product is selected is the “number”. You have to be involved right from the beginning as it is difficult to improve the acoustic qualities of the wall after it has been installed. We would urge you to read this article for additional information on this topic.

Inspect the moveable wall surrounding construction:

The moveable wall is installed in a predesigned opening. The acoustics of the moveable wall is only as good as the opening in which it is installed. You may think that the sound you hear is coming through the wall itself but it may in fact be going around, over or under the wall. Check the project specifications and drawings to see what was specified and then visually inspect what is actually in place. The following article describes methods and measures that must be or should have been taken relating to the moveable wall contiguous construction in order to ensure maximum sound control.

Visually inspect for “sound leaks”:

There is a simple way to do this. Turn on all the lights on one side of the wall and off on the other. Go to the dark side and look for light leaks. If you can see light between panels or over/under panels then this represents a sound leak. Call your local Moderco distributor and he will quickly readjust your partition to eliminate these sound leaks.

Moderco would be happy to work with you if your partition is not performing up to your expectations acoustically regardless of whose partition you have installed. Please call us at 1.800.363.3150 and we will discuss your issues and arrange for a personal on site visit.