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Topics - audiot1949

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1
Hi All,
Because I think that measuring according impedance to faber's YOUTUBE and other sources seemed to me rather complicated, I made my own (short) description.
This describes step by step 'how to' setup and measure the impedance of loudspeakers.
You will find a setting for low impedances and for 100 V systems.
I packed all the cabling, switches and resistors in a junction box. This prevents much fiddling with the cables.
Unfortunately the file is 1.4 MB large so it exceeds the upload limit.
Because of forum restrictions I can't upload the in this file mentioned EXCEL calculation too.
Therfore I will give you a link to download both in a folder.
https://app.syncwerk.com/d/228b11ea0d/

After working with 2 FFT I find this app really really great!

...At my page you might find another interesting article:
http://members.aon.at/ernstgenser/Artikel/prediction_of_soundlevel_in_offices_eng.pdf

Have fun!

2
Electroacoustics Toolbox / Oscilloscope: Crest & RMS & Peak
« on: November 01, 2015, 01:15:20 PM »
It seems, that Crest & RMS & Peak are calculated from the start to the end of the recorded thread.
Is this really so intended or shouldn’t these values calculated between Cursor 1 and 2?

3
Electroacoustics Toolbox / Nice to have: “waterfall” diagram
« on: October 31, 2015, 10:48:13 AM »
(this should be not mixed up with a “spectrogram”)
This waterfall diagram gives normally in the x-axis the frequency, in the z-axis the level and in the y-axis the time and shows the “decay” of the sound.
It is e.g. calculated by a sweep like produced by the excitation of the DFFT and can be used in rooms in the far field to detect modes and resonances. In measuring loudspeakers (near field) it can be used to detect resonances.
(please see to enclosed example)

4
It seems that the setting of the values of „Pre-sends“ has no influence.
The excitation runs nonstop when you start the machine regardless whether you enter 0 or 99. In some cases it makes sense to take single shots only.
In my opinion it would make more sense either to store automatically the latest measurement after the given pre-send # is achieved OR the function stops when the # is achieved. Then you can decide to store it or start a new measurement.

5
Electroacoustics Toolbox / Spectrogram 3D Surface: missing x/y/z scale
« on: October 31, 2015, 10:46:49 AM »
You can rotate the diagram but the scales are missing.
The shown scales respond to the 2D diagram and not to the 3D.
Please have a look at the screenshot.

6
Well, they are in the collected measurement data as values. To have it as selectable curves too would be nice!

7
Electroacoustics Toolbox / Room Tools Analyzer: General
« on: October 31, 2015, 10:45:19 AM »
This is really, really a great and awesome tool!
Like it very much, but you should provide a “cooking recipe” with a block diagram and screen shots how to set it up and get it work.
It took me hours to make the setup and get sensible results because of missing info.
Ben, thank you again, without your detailed help I couldn’t have got it work properly!

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