VituixCAD - Page 169

Oneminde · 2nd December 2019, 06:21 PM

Great update.

Oneminde · 3rd December 2019, 04:48 AM

The Spin-O-Rama VCAD feature is the best thing that has happened to me in my study's the last two years.
Its a lot to take in and learn and I am more than willing to do that, I just want to say thank you for opening up my eye's to a new segment of measurements.
Its going to make my life simpler once I have dialed in the techniques involved.

kimmosto · 4th December 2019, 01:39 PM

Rev. 2.0.33.2 (2019-12-04)

Convert IR to FR
* Added Z/U button to set default values for impedance, voltage and acceleration exports. Replaces automatic setting added to rev. 2.0.32.0 (2019-11-28). Manual operation is more convenient if 'Microphone Used On' was accidentally unchecked while acoustical measurements with ARTA.

ernperkins · 4th December 2019, 07:09 PM

I've finally decided to try out VCAD. I've used other design programs, but the feature list for VCAD keeps growing. I read the "VCAD Measurement Preparations for REW" and I really only have one question:

The .pdf states "Rotation center is typically on surface of front baffle for the tweeter". My manual table is somewhat small so usually I center the speaker on the table. This results with the center of rotation being at the center of the speaker, not at the surface of the front baffle.

What is the recommended solution? I can think of a couple (e.g. bigger table), but just want to make I sure I'm understanding rotation correctly.

Thanks....

ergo · 4th December 2019, 07:56 PM

If you rotate around speaker center then the distance from the speaker dome/cone to the microphone will not remain constant and that will be a problem the bigger this offset is. I solved this also by building a bigger turntable (got pretty big diameter lazy susan bearings from Alibaba with a reasonable price).

kimmosto · 07:59 PM

^^Bigger table works ... until you have much bigger speaker or need to measure vertical plane of rectangular ribbon/planar without possibility to just rotate the driver. Might need some temporary baffle for measurements only.

Rotating top plate does not have to be circular and axis hole not in the center. Square 80x80cm should be quite adequate. Axis hole e.g. 20cm from the edge to allow tilted or stepped front baffle or spikes in front of speaker etc.
Base plate could be circular, diameter close to 100cm and axis hole in the center.

Some kind of thin rod with four legs for distance measurement could be nice because that is the most difficult phase due to accuracy requirement. With measurement tape it's easiest to rotate table +90 deg, align mic with front baffle and adjust distance from mic to the center of DUT to 1000 mm. Then rotate to -90 and verify alignment and distance 1000 mm i.e. system rotates vertically without swinging.

ernperkins · Yesterday, 07:03 PM

Thanks for the responses. I'll look into modifying my table.

2nd December 2019, 06:21 PM	#1681
Oneminde diyAudio Member Join Date: Jun 2014 Location: Darkside of the moon.	Great update. __________________ In order to become sane in an insane world, you must first become insane.

3rd December 2019, 04:48 AM	#1682
Oneminde diyAudio Member Join Date: Jun 2014 Location: Darkside of the moon.	The Spin-O-Rama VCAD feature is the best thing that has happened to me in my study's the last two years. Its a lot to take in and learn and I am more than willing to do that, I just want to say thank you for opening up my eye's to a new segment of measurements. Its going to make my life simpler once I have dialed in the techniques involved. __________________ In order to become sane in an insane world, you must first become insane.

4th December 2019, 07:57 PM	#1686
kimmosto diyAudio Member Join Date: Oct 2005 Location: Kuopio	^^Bigger table works ... until you have much bigger speaker or need to measure vertical plane of rectangular ribbon/planar without possibility to just rotate the driver. Might need some temporary baffle for measurements only. Rotating top plate does not have to be circular and axis hole not in the center. Square 80x80cm should be quite adequate. Axis hole e.g. 20cm from the edge to allow tilted or stepped front baffle or spikes in front of speaker etc. Base plate could be circular, diameter close to 100cm and axis hole in the center. Some kind of thin rod with four legs for distance measurement could be nice because that is the most difficult phase due to accuracy requirement. With measurement tape it's easiest to rotate table +90 deg, align mic with front baffle and adjust distance from mic to the center of DUT to 1000 mm. Then rotate to -90 and verify alignment and distance 1000 mm i.e. system rotates vertically without swinging. Last edited by kimmosto; 4th December 2019 at 07:59 PM.

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4th December 2019, 01:39 PM	#1683
kimmosto diyAudio Member Join Date: Oct 2005 Location: Kuopio	Rev. 2.0.33.2 (2019-12-04) Convert IR to FR * Added Z/U button to set default values for impedance, voltage and acceleration exports. Replaces automatic setting added to rev. 2.0.32.0 (2019-11-28). Manual operation is more convenient if 'Microphone Used On' was accidentally unchecked while acoustical measurements with ARTA.

4th December 2019, 07:09 PM	#1684
ernperkins diyAudio Member Join Date: Nov 2009	I've finally decided to try out VCAD. I've used other design programs, but the feature list for VCAD keeps growing. I read the "VCAD Measurement Preparations for REW" and I really only have one question: The .pdf states "Rotation center is typically on surface of front baffle for the tweeter". My manual table is somewhat small so usually I center the speaker on the table. This results with the center of rotation being at the center of the speaker, not at the surface of the front baffle. What is the recommended solution? I can think of a couple (e.g. bigger table), but just want to make I sure I'm understanding rotation correctly. Thanks....

4th December 2019, 07:56 PM	#1685
ergo diyAudio Member Join Date: Mar 2001 Location: Tallinn, Estonia	If you rotate around speaker center then the distance from the speaker dome/cone to the microphone will not remain constant and that will be a problem the bigger this offset is. I solved this also by building a bigger turntable (got pretty big diameter lazy susan bearings from Alibaba with a reasonable price).

Yesterday, 07:03 PM	#1687
ernperkins diyAudio Member Join Date: Nov 2009	Thanks for the responses. I'll look into modifying my table.