Operable Partitions and acoustics (sound separation) go hand in hand. In fact many would say that acoustic control is the number one customer consideration when selecting an operable partition supplier. And the way that virtually all partition suppliers attempt to prove to the customer that their partition will minimize the transfer of sound is by the submission of a test showing an STC value – anywhere from the high 40’s to the mid 50’s. Subsequently the recipient looks at the number, compares it to other suppliers under consideration and assumes that the higher the number the better the ability of the wall to stop sound transference.
Wrong assumption! There is much more to a sound test than a high number.
STC is determined by installing a test specimen in a “test assembly” with the typical partition dimensions being 14’ wide X 9’ high and which separates a room having a noise source from a receiving room. The sound transmission loss (STL – the difference between the sound level in the source room and the receiving room) – is measured at different sound frequencies (Hz) with the results plotted on a graph in order to calculate the STC using a specific procedure and formula. The higher the calculated STC the more quiet it is in the receiving room. The procedure is named ASTM E-90. The E-90 test procedure is regularly reviewed and sometimes “changed” with the year the change takes place designated by a suffix: for example E-90-04 would indicate that the procedure was modified in 2004. The standard has been revised several times over the years but since it is definitely not reasonable to expect that manufacturers re-test their products every time a revision occurs, a generally accepted rule of thumb has evolved. That is that one can with confidence accept ASTM E-90 sound test results as being equal if the tests submitted are no more than 3 test procedures of each other in an upward progression with the earliest as the comparative choice. The latest E-90 test is E-90-09. The three previous are E-90-99, E-90-02 and E-90-04. These 4 procedures would be considered as equals.
Call Moderco so that we can visit with you to review our sound tests and if you wish compare them to others you may have. 1 800 363-3150
Thank you for considering Moderco as your operable partition supplier.