@4thtry said:
...Is this a mistake on my part? I double checked to make sure I had all the component values entered correctly. Should we be using "minimum phase" for this particular model? Or should we be using the raw, as measured, phase data?
...I am only at the medium skill level on VCAD and often make mistakes.
I often make mistakes too and I made the mistake this time. I NEVER use minimum phase now that I have a two-channel system. In this case, because Geoff started out using traced data, I was curious how big the difference would be if someone designed the speaker using traced and minimum phase data vs the actual measurements. I had literally made about 20 xo versions and at some point was looking at the minimum phase issue and must have selected minimum phase and never set it back. Once all of the driver measurements are loaded, I don't usually look at the "drivers" window anymore.
Geoff, just to point out what Bill was seeing in VituixCAD... You can see in the upper-left pane that the current reverse null (dotted blue overlay) is not nearly as deep as before. That in itself isn't a huge deal, in fact the on-axis SPL curve might be a little smoother in the 4-6kHz range. On the other hand, in the upper-right pane you can see the green and red phase curves are now running parallel to each other, whereas in the prior post they were almost perfectly overlapped. Rather than show the impedance curves in the lower-right pane this time, I am showing the vertical polar plot. I added a yellow line at 0-degrees and you can see that a little more of the output is BELOW the zero-degree line, thus Bill's observation that the main vertical lobe is tilting down somewhat.
Comments
No probs, Vituix is beyond my understanding and competence and I'm also interested to learn how it works.
I hope to have the proper XO wired up this weekend, but other things may get in the way.
Geoff
I often make mistakes too and I made the mistake this time. I NEVER use minimum phase now that I have a two-channel system. In this case, because Geoff started out using traced data, I was curious how big the difference would be if someone designed the speaker using traced and minimum phase data vs the actual measurements. I had literally made about 20 xo versions and at some point was looking at the minimum phase issue and must have selected minimum phase and never set it back. Once all of the driver measurements are loaded, I don't usually look at the "drivers" window anymore.
Geoff, just to point out what Bill was seeing in VituixCAD... You can see in the upper-left pane that the current reverse null (dotted blue overlay) is not nearly as deep as before. That in itself isn't a huge deal, in fact the on-axis SPL curve might be a little smoother in the 4-6kHz range. On the other hand, in the upper-right pane you can see the green and red phase curves are now running parallel to each other, whereas in the prior post they were almost perfectly overlapped. Rather than show the impedance curves in the lower-right pane this time, I am showing the vertical polar plot. I added a yellow line at 0-degrees and you can see that a little more of the output is BELOW the zero-degree line, thus Bill's observation that the main vertical lobe is tilting down somewhat.
Thanks David
Geoff