## Importing MLSSA frequency response files into a contour graphThis series of Select file-group in the file-dialog or drag from File-Manager. Each data-set gets assigned a record of parameters. Decide which parameter
forms the y-axis of the contour, here "Axial angle". Also we provide
the measurement distance, which is 1m and the driving voltage, which is
4V Ready. The import gets named and organized in the tree-list and you may
add details of the measurement in edit-box on page The sibling curve-graphs allow for projections. The projection onto
the x-Graph shows the frequency response at any angle. For in between angles
the continuous phase
interpolation technique is used, which allows for correct
interpolation between two complex-valued functions. The green curve
is a power-integration over all data-sets at each frequency
(see The other projection yields the polar-plot. The red curve shows
the SPL at 2.5kHz and the the blue curve
is a power-integration over a 3rd octave at this frequency (see
The property dialog informs about details and integrals of the data-sets. For example it tells us that each spectrum has 4096 points on a linear grid.
Often it is useful to down-sample such data to more manageable size.
We resample to 400 points on a log-grid and sub-sequentially smooth with a window of 6th of an octave relative width. The dialog reports also the point distribution of the original as well as the re-sampled data-sets, ie 400 points corresponds to 33.25 points per octave. Clicking Now let's see what is in the box. The real part of sound pressure measurements are usually wavy due to the presents of delay caused by the traveling time from the source to the microphone. The plot demonstrates that the original curve with 4096 points and the down-sampled curve with 400 points are almost identical thanks to the Continuous Phase Technique. Using 8031-A |