Member
Joined 2003
I've read the section on the Optimizer in the VCD 2 Help, but I found the VCAD 1.1 video was a lot more detailed and a lot easier to follow.Did you read what's in the help file?
(Did that record just skip again?)
v1.1 is simpler because some features were not yet done. v2 vs v1.1:
I have started to optimize by preference rating with own/customized multipliers. Just one or two clicks after multipliers are entered and parameters selected.
Projects with terrible on-axis response require optimizing with LW and power response, but usually preference rating can take care of balancing.
I have started to optimize by preference rating with own/customized multipliers. Just one or two clicks after multipliers are entered and parameters selected.
Projects with terrible on-axis response require optimizing with LW and power response, but usually preference rating can take care of balancing.
Member
Joined 2003
Given that you've read the documentation and watched the old YT video, do you have specific questions about it?
Given that you're loading traced data, I would stick to optimize by axial response or listening window at 100% weight. Off-axis information created using diffraction tool has limited accuracy so it is only to provide general idea of driver directivity based on size, but unlikely that it will match reality >1kHz for power & DI charts.
With full measured data, I tend to prefer optimizing by listening window and in-room response at 50% weight. I don't find I get better results using preference rating over this method. Generally my listening window target would be -0.2dB/oct slope from 100Hz - 10kHz, and in-room target slope will vary by the speaker, generally around -0.8 or -0.9dB/oct slope from 100Hz to 10kHz.
Keep in mind the optimizer does not design your crossover for you, only adjust the values as best it can to hit the target you provide. It also optimizes only amplitude response, so you still require understanding of driver limits such as distortion performance.
Thanks Guys. That's great information.
I'm trying to learn VCAD while I'm still building my enclosures (FAST design with a QWTL for the woofer).
I'm currently just using the manufacturer's FRD and ZMA files, but will be taking in-enclosure measurements outdoors to use for the actual crossover design.
Even though I have designed crossovers before, that was 30 years ago using a DOS version of CalSod.
CalSod was very basic compared to VCAD, and my memory is shot, so I could be considered a Newbie.
@DcibeL Regarding a question - when I read the v2 Optimizer Help, I wasn't sure whether the idea was to optimizer each 'leg', or whether to do some basic designing of the full crossover then run the Optimizer across the full crossover.
The old YT video clarifies that initially each leg should be optimized separately.
The old YT also shows all the settings to use before optimizing e.g using delay setting to align phase with minimum phase..
However, you have given me some great guidelines for some of those settings.
I'm trying to learn VCAD while I'm still building my enclosures (FAST design with a QWTL for the woofer).
I'm currently just using the manufacturer's FRD and ZMA files, but will be taking in-enclosure measurements outdoors to use for the actual crossover design.
Even though I have designed crossovers before, that was 30 years ago using a DOS version of CalSod.
CalSod was very basic compared to VCAD, and my memory is shot, so I could be considered a Newbie.
@DcibeL Regarding a question - when I read the v2 Optimizer Help, I wasn't sure whether the idea was to optimizer each 'leg', or whether to do some basic designing of the full crossover then run the Optimizer across the full crossover.
The old YT video clarifies that initially each leg should be optimized separately.
The old YT also shows all the settings to use before optimizing e.g using delay setting to align phase with minimum phase..
However, you have given me some great guidelines for some of those settings.
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Member
Joined 2003
The idea of how to best use the tool is up to you. It has features available to provide high pass or low pass or complex targets, and optimize all components or only a select few so there are many ways to utilize it.
I personally rarely use the optimizer for anything other than overall system response target. It doesn’t do so well with Notch filters I find, so if a design requires a notch it may be better to set up the notch manually then exclude those components for optimization .
Increment is 3 dB in initial/default user.config, but it's possible that increment changes to 5 dB if the value is missing or reading of user.config fails.
I just made tiny change to the latest build of 2.0.87.1 (2022-06-12): increment is set to 3 dB if value is missing or reading of user.config fails.
If that does not help, you need to modify user.config manually. Here is screenshot from my user.config:
Was the problem also with primary Directivity chart on the left, or just with secondary on the right (shared canvas with Impedance chart)?
I noticed that secondary chart was using chart object's default (5 dB) instead of setting in user.config (3 dB by default).
Anyway, I've abandoned polar map almost completely. Spinorama in Power & DI and Waterfall in Directivity is adequate in practice.
Designing and optimizing strategy depends on project and personal preference. Setting target curves for each driver takes some time, but it certainly helps visualizing how slopes and levels should be in order to get certain total response. For example:
1a. Set target curve for driver 1. Limit optimized frequency range; include band pass range and slopes 2-3 octaves, but not above break-up.
1b. Design XO connection for driver 1. Set initial values manually so that optimizer has easy job to finalize without running off the road.
1c. Select parameters to optimize for driver 1, and optimize to target. When done, exclude optimized parameters with Optimize off.
2a,b,c. Same steps for driver 2
3a,b,c. Same steps for driver 3
4a. Set polarities of drivers or active buffers.
4b. Set delay for mid and tweeter with active buffer if project has active filter.
5a. Set target curve for total axial or LW and power response or PIR, or select multipliers for custom preference rating (last equation). Set weighting factors for axial and average. As already said, optimizing with preference rating is much easier because you don't have to set target lines/curves. Just few multipliers. Optimizing with average requires off-axis data for all drivers, 0-90 deg for half space, and 0-180 deg for full space designs. Without off-axis data you can optimize on-axis only.
5b. Select parameters which are included for optimizing total. For example you can include capacitor(s) for each high pass slope, but leave all components for low pass slopes excluded. Include parameter which affects to gain of peak/notch filter, but exclude components/parameters which affect to center frequency.
5c. Optimize.
6a. Return back optimizing driver's band with different XO frequency or order if directivity features are impossible to get good enough.
Hey Kimmo.
I often use VituixCADs SPL Tracer. And quite often it is necessary to digitize and export graphs of impulse response (or even different scientific data !) from 0s or 0Hz, but VituixCAD now exports only from 5Hz (as I understand it is because of Hilbert transform that estimates minimum phase). Please, can you add an option to export the data without minimum-phase estimation but from 0hz, also Log SPL scale and extended frequency range option would be helpful in some case (VituixCAD has on of the most convenient graph digitizers so I often use it not only for SPL charts)
I often use VituixCADs SPL Tracer. And quite often it is necessary to digitize and export graphs of impulse response (or even different scientific data !) from 0s or 0Hz, but VituixCAD now exports only from 5Hz (as I understand it is because of Hilbert transform that estimates minimum phase). Please, can you add an option to export the data without minimum-phase estimation but from 0hz, also Log SPL scale and extended frequency range option would be helpful in some case (VituixCAD has on of the most convenient graph digitizers so I often use it not only for SPL charts)
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Hi, I feel the answer to this question should be on the forum somewhere but I can't find it so sorry if this has been asked and answered elsewhere.
The Vituix help file lists a number of filters available in the library with the linear phase filters highlighted in blue. However my installation doesn't have the linear phase filters in the library. How do I get hold of these? I'm running V 2.0.85.8
The Vituix help file lists a number of filters available in the library with the linear phase filters highlighted in blue. However my installation doesn't have the linear phase filters in the library. How do I get hold of these? I'm running V 2.0.85.8
I've answered my own question, you can select the active block and choose the shape from the drop down.
If you’d like a tool that’s less focused on audio and can handle other types of graphs or plots as well, I recommend WebPlotDigitizer. It’s available online as a web app or as a cross-platform download and handles multiple axes and datasets in the same image.Hey Kimmo.
I often use VituixCADs SPL Tracer. And quite often it is necessary to digitize and export graphs of impulse response (or even different scientific data !) from 0s or 0Hz, but VituixCAD now exports only from 5Hz (as I understand it is because of Hilbert transform that estimates minimum phase). Please, can you add an option to export the data without minimum-phase estimation but from 0hz, also Log SPL scale and extended frequency range option would be helpful in some case (VituixCAD has on of the most convenient graph digitizers so I often use it not only for SPL charts)
https://automeris.io/WebPlotDigitizer/
Actually VituixCAD has been able to trace and export linear X axis from 0 for longer than year with Edit->Copy raw SPL or Copy raw Z to the clipboard command, but there has been some limits in Y-axis maximum and minimum. Those limits are expanded in the latest revision to -10000...+10000 for both SPL and Z axis.but VituixCAD now exports only from 5Hz (as I understand it is because of Hilbert transform that estimates minimum phase). Please, can you add an option to export the data without minimum-phase estimation but from 0hz, also Log SPL scale and extended frequency range option would be helpful in some case (VituixCAD has on of the most convenient graph digitizers so I often use it not only for SPL charts)
For example tracing impulse and step responses at the same time: impulse with SPL scale and Step with Z scale:
Hi Kimmosto:
I've been looking at the room tab for a long time and only today wondered why there is no box for entry of an absorption figure for the left wall reflection. Surely it would be interesting to see the effect of absorption at the first reflection point! Looking in the help file for an explanation, I found " Adjustable absorption in dB is available for both walls, ceiling and floor."
not nitpicking, just curious
Jack
I've been looking at the room tab for a long time and only today wondered why there is no box for entry of an absorption figure for the left wall reflection. Surely it would be interesting to see the effect of absorption at the first reflection point! Looking in the help file for an explanation, I found " Adjustable absorption in dB is available for both walls, ceiling and floor."
not nitpicking, just curious
Jack