WinFlag - Material acoustic Performance Estimation Software
Do you need to estimate the acoustic performance of constructions combining different material layers such as porous materials (e.g. mineral wool), solid and perforated plates (slotted, with circular holes, microperforated)?
Download and evaluate WinFlag 15 days for free from here. From the same link you may also download and evaluate our low price alternative WinFlag ver. 1.0. For pricing and for purchasing WinFLAG, click here. If you have questions about WinFlag, please use the WinFlag/WinRT60 forum.
We also recommend looking at our measurement system WinMLS and room prediction software WinRT60.
User Reviews
These programs (WinFlag and WinRT60) are exceptionally user-friendly and will be useful tools in any acoustic engineer’s toolbox
- Carl Hopkins, University of Liverpool, UK
My every day work is to compare, evaluate, optimize and calculate acoustic materials.
One of the most efficient tools to do this, besides doing the measurements, is using WinFlag to predict, verify or recalculate materials, material designs and “measurement” results. See more here.
- Jan Borgers
I have to say I love this program. It is a matter of seconds to design an absorber panel for a specific frequency, and adjust its Q. Compared to similar software it is more straightforward, quicker, and looks overall more professional.
- Thalis Menexelis, Athen, Greece
The manual and program looks very intuitive and good with references for the models. I think this program is a useful tool for acoustics consultants and even producers of absorbers.
- Anders Buen, Brekke & Strand Akustikk AS, Norway
WinFLAG Overview
WinFLAG does the job of calculating the absorption coefficient, the impedance and the sound reduction index for constructions combining different material layers such as porous materials (e.g. mineral wool), solid and perforated plates (slotted, with circular holes, microperforated). WinFLAG version 2.4 also calculates the attenuation of noise in ducts, e.g. air-conditioning ducts, lined with the chosen layers.
Calculations may be performed at single frequencies or as mean values in one-third-octave bands, for free and diffuse field sound incidence. For exported data (MS-Excel or ASCII) values in octave-bands are presented. One may estimate the absorption coefficient measured in a standard reverberation room according to ISO 354. These absorption coefficients may be directly exported to the program WinRT60 that calculates the reverberation time in rooms.
For its calculations, WinFLAG uses, except when handling flexible plates, a transfer matrix method with only two physical variables: sound pressure and particle velocity. This implies that porous materials are treated as equivalent fluids, which will not completely represent certain foam materials. The program will, however, give a proper model in a vast number of cases and certainly be useful both for acoustic consultants and for students in acoustics as well. For details please see the WinFLAG manual.
· Calculates the absorption coefficient for 19 different types of layers, including 4 different models of porous materials. The absorption coefficient may be calculated, with some exceptions, for any combination or any number of these layers limited to a total of 20 layers. An 20th type of layer, the infinitely hard wall, i.e. a rigid backing, may be included in the case of absorbers placed against a hard wall in a room.
· Absorption coefficients obtained in a standard reverberation room (the commonly used product data after ISO 354) may be estimated, as well as the weighted sound absorption coefficient aW according to ISO 11654.
· The sound reduction index in dB (sound transmission loss) is simultaneously calculated for all combinations not including the infinitely hard wall. The weighted sound reduction index Rw according to ISO 717 Part 1 is also calculated when applying a diffuse field option and calculating results in one-third-octave band.
· To simulate structural connections in double lightweight walls, such as studs or point-like connections (“ties”), types of layer named Structural bridges, are introduced. The connections may be simulated to be either infinitely stiff or flexible.
· The acoustic impedance is also simultaneously calculated in all cases when an angle of sound incidence is specified.
· All data mentioned above may be calculated for a given angle of incidence or in a diffuse field.
· Calculations are performed at single frequencies or as mean values in one-third-octave bands. There is also an option for exporting calculated results as mean values in octave bands.
· As an add-on to the program the attenuation of noise in ducts, e.g. air-conditioning ducts, lined with the chosen layer configuration may be calculated.
· A report window in Rich Text Format (.rtf file) is implemented where specifications, tables of results and diagrams may easily be imported.
· Results, together with specifications for the combination of layers, may be exported to a plain text file (ASCII), alternatively to a Microsoft Excel file.
· A chosen combination of layers, a configuration, may be saved to a file and later imported for additional calculations. The same applies to single layers, which enables the user to build up a library of material layers.

New features in WinFLAG version 2.4 (upgrade from version 2.3)
Version 2.4 introduces the following two features to improve on the prediction of sound transmission:
· In former versions, the thick (elastic) plate layer could be coupled to fluid layers only, i.e. air and porous layers. In the present version, however, elastic layers may be directly coupled enabling calculation of the transmission loss of e.g. laminated glazing. This is accomplished by coupling the relevant 4x4 transfer matrices representing the individual thick plate layers; see figure above showing the effect of laminating two sheets of glazing with 1.5 mm PVB (polyvinylbutyaryl). Red curve – 3/8 inch glass.
· Coupling layers may now be chosen to be infinitely stiff, simulating e.g. wooden studs in double-leaf walls, or they may be defined as flexible with a basic stiffness applying to the low frequency range. A certain frequency dependence of this stiffness is introduced.

WinFlag Links
Purchase WinFLAG (includes prices).
Evaluate WinFLAG (includes download link).
Manual for WinFLAG 2.4 or WinRT60 2.0 (right-click to download).
WinFLAG forum.