Sound Reduction Index (R) reduction edit, the Sound Reduction Index is expressed in decibels sound (dB).
The index sub- script 2 in the Waterhouse correction indicates the receiving room.The maximum difference in any single frequency band between these two scans formula must not exceed 1-0.p p The size of the Waterhouse correction is given for three typical labora- tory room sizes in Fig.Jonasson /p p dB /p p 2o18 ltttttt-i-2T; -l -dT i i i Average -iii /p p r w-J " Max ii /p p s 8 25 2o 5 5 8 t Frequency.The calculation method used to produce spreadsheet the Sound Reduction Index takes into account the relative size of the tested rooms, and the size of the tested panel, and is therefore (theoretically) independent of these features, therefore a 11 panel of plasterboard ( drywall ) should.In the traditional ISO method two source positions pictures have been used by delab, DTI and VTT (Technical Research Centre of Finland).p p The Waterhouse correction cannot be expected to give the whole truth emission as it assumes diffuse field conditions in the middle reduction of the room and takes no account of the modal behaviour of the sound genesis field.The three laboratories were the Swedish National Testing and Research Institute (SP) in Bors, the Acoustic Research Center (delab) in Trondheim reduction and the Danish Technological Institute (DTI) in Aarhus.If the difference is larger than 1-0 dB two new scans with different patterns must be carried out. Jonasson /p p dB Waterhouse correction /p p 1 O0 m3 /p p 3 50 m3 /p p 200.
Sound reduction index 285 /p p dB Souttl mtucfion inckx!
The reference curve is moved in 1 dB reduction steps until the coach total of the unfavorable deviations (measured points on the graph below the reference graph) is as machine close to 32 as possible cider but not vinegar greater than.The small differences between the.p p Also from Fig.With Waterhouse correction in the receiving room.The measured formula intensity will become reduction too low because the energy coming from the receiver room will only be partially reflected back to the room.p p If the test object is flush mounted in a wall reduction in the receiving room the measurement recipe surface is box-shaped and recipe the closing of this surface along the boundary to the wall becomes critical.In this case the requirement /p p Lp - Ztn lt; 6 dB 10) /p p has been vinegar used whenever the receiving room surface of the test object is sound absorbing.A number of indexes are defined which each offer various benefits for lift different situations.0.5 seconds is often cited as approximately average for a medium-sized, carpeted and furnished living room.Unfortunately most of these indicators can not be evaluated with commercially available instrumentation while recipe carrying out real-time scanning. Due to not requiring detailed and accurate knowledge cider of the dimensions of the test rooms, this index is easier to obtain, and arguably of slightly more relevance.