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MLSSA :
To obtain the necessary ASCII file with MLSSA, it is necessary to make the measurement, transfer to
FFT to get the response in frequency Transfer Function Magnitude and visualise it with some
smoothing. Once the frequency response is on screen, go to the option Transfer, Export, Bode, select
the phase (normally Actual-phase), select a resolution of at least 1/6 Octave, give a name to the file,
save it with a .txt extension.
"Transfer Function Bode Plot - dB volts/volts (eq)"
"Hz"
18.42571,
36.85141,
55.27712,
73.70283,
92.12853,
110.5542,
221.1085,
257.9599,
...
WINAIR :
Select MLS as analysis signal and once the measurement has been made, go to the Storage section,
enter the name of the file with a .txt extension and press the Save button to save it to the directory
where the WinAir program is located. The saved format must coincide with the following:
Samples per second 44100
Number of points 1024
Hz
21.533
43.066
64.600
86.133
107.666
129.199
150.732
172.266
193.799
215.332
236.865
258.398
279.932
...
SIA Smaart Pro / Smaart Live:
The SIA Smaart Pro Real-Time Module is provided with the option ASCII Save in the menu File. It is
recommended to use 44100 or 48000 as sampling frequency and a FFT size superior or equal to 1024
points, as well as to make the measurement with an Averages number greater than 25 in order to
have a stable response. The measurements must be done using the program in Transfer Function
Mode.
The measurement can be done using White Noise with FFT analysis or Pink Noise if you use a 1/3 or
1/6 Octave analysis. It is also possible to achieve a result using music with a great spectral content
and a high averages value in the measurement. The measurements must be done introducing the
direct signal to one channel of the sound card and the measurement signal from the acoustic system
by means of a microphone and amplified up to line level to the other one. In this case it is convenient
to adjust the delay of the signal with the option Delay Locator.
"Mag (dB)" "deg"
8.800242,
12.55392,
9.681987,
11.5648,
12.57369,
18.3404,
12.62453,
5.280994,
...
WinAIR saved file
Amplitude
210.38184
51.68376
116.45122
42.01191
121.01157
27.09770
15.25970
19.68722
46.94252
30.90430
53.93416
16.91670
20.37465
...
RAM Audio LMS244 Digital Controller
1.53268
-120.637
-62.79101
123.8057
102.3705
121.5294
-41.98371
-60.50087
...
Phase
0.00
1.40
-1.27
0.18
1.14
-0.13
0.10
1.40
-0.96
0.24
-0.58
-0.79
1.50
...
15
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