VituixCAD v2

[Reet]

Thank you Kinmo, I appreciate your insight.

[kimmosto]

...W-W distance of 620mm for the inner pair of woofers, so the distance is longer than half wavelength, closer to 1x.

That is okay if target is to avoid early vertical reflections. Vertical beam will be quite narrow at some frequencies.
My target is usually to attenuate primarily the lowest floor dip at ca. 300 Hz with WW-WW pair.

This is also WWMTMWW but with cardioid woofers. Woofer responses are simulated ideal super-cardioid. Not exactly comparable with your projects but might give some idea what lower XO would do.

[Reet]

In my case, currently I have a crossover point around 500Hz, and W-W distance of 620mm for the inner pair of woofers, so the distance is longer than half wavelength, closer to 1x. Perhaps I should lower the crossover frequency, but am trying to balance the ideal frequency ranges for distortion/SPL performance of the drivers, asking for low frequency output from the midrange drivers will increase IMD through the midrange which I would like to avoid. Vertical directivity looks a bit of a "laser beam" at the moment, however horizontal, power & DI are looking good to me.

[kimmosto]

For this design I have attempted the 0.5 way filter for the outer most woofer, however I didn't obtain a better result than just running all 4 drivers in parallel with a lower cost filter.

Sounds normal. W-W distance is usually shorter than half wavelength at XO so 0.5-way filtering can be even harmful. M-M pair could have some 0.5 way features for upper mid-range if mid drivers are large causing too much vertical directivity right below upper XO. It also turns main axis slightly upwards to support listening while standing. Not much, but flexibility might improve depending on listening habits.

[Reet]

Workaround is to mute others, save on-axis to overlay and then unmute. Needs redoing after changes. For example, 4-way with two side woofers:

Challenge is that certain driver name or index in driver list does not necessarily create a group or way. At least in theory the same driver data can be used for different ways/bands, though 0.5 ways and power tapering solutions are more typical cases where the same driver data is distributed with different filters into a single band.

Thank you, this is helpful. The design I'm working on is a WWMTMWW, the woofers are 8 ohm drivers in series/parallel arrangement, and the midrange is a pair of 4 ohm drivers wired in series. I am running some filter transfer function simulations using IR export and convolution via APO EQ, I just have to remember to add 6dB of gain to the IR export for a single driver.

For this design I have attempted the 0.5 way filter for the outer most woofer, however I didn't obtain a better result than just running all 4 drivers in parallel with a lower cost filter.

[kimmosto]

directivity plot in the diffraction tool.

I use this workaround. Export off-axis data to temp directory with default name and feed to driver. Fast to redo after a change in diffraction settings.

[kimmosto]

...plot of the total output of the pair of driver in series

Workaround is to mute others, save on-axis to overlay and then unmute. Needs redoing after changes. For example, 4-way with two side woofers:

Challenge is that certain driver name or index in driver list does not necessarily create a group or way. At least in theory the same driver data can be used for different ways/bands, though 0.5 ways and power tapering solutions are more typical cases where the same driver data is distributed with different filters into a single band.

[Reet]

Hi Kimmo,
I am designing a large system that uses a pair of the same driver in series. For this type of system, VituixCAD shows the actual SPL and filter response that each individual driver sees, so the response is 6dB lower than what the total output is. Ideally in this scenario I would like to see a plot of the total output of the pair of driver in series, this will make it easier to determine where the specific crossover frequency is, as well for exporting IR response. Currently I need to boost the level by 6dB to represent the correct output level. It would be great if there were an option for this.

Another addition you might consider is a directivity plot in the diffraction tool. I understand that the simulation of directivity is limited in accuracy, but I think it can provide a bit more insight into baffle shape/size choices and the impact of large vs small roundover.

[kimmosto]

3.0.1.7 (2026-08-20)

Main, Optimizer

• Hide button replaced with Close button.
• Added 'Hide targets when closed' checkbox.

Main, Copy biquad coeffs...

• Eliminated useless error message when coefficients were exported before project was saved.

[Reet]

Sounds good to me 😊

[kimmosto]

This is done, but not yet packed and published:
Hide button is replaced with Close button (ends optimizing and closes the window) and 'Hide targets...' checkbox added to hide or leave curves visible w. What do you think?

[kimmosto]

Hide button is a bit odd UI interaction, but it works for my purpose. Thanks.

I might have forgotten original purpose of Hide button. Perhaps it was for very small or low resolution displays and low CPU performance; to monitor optimizing and curves without keeping window open above chart area. Optimizer stays in memory and can run with hidden window. Closing with X stops and clears optimizer from memory. So it's kinda vintage feature.

[Reet]

Hide button is a bit odd UI interaction, but it works for my purpose. Thanks.

[kimmosto]

I prefer the manual control over which traces are shown.

Targets stay visible and can be hidden via context menus as earlier if you close Optimizer with Hide button. New logic still shows and hides the targets according selected option in the Optimizer. I publish charts quite often so hiding target curves every time after closing the Optimizer has started to glitch.

This is probably not the final solution so new ideas are welcome. For example, both SPL and CTA-2034 targets are now shown when 'Preference rating' is optimized even if the slopes are not optimized (SL_ON, SL_LW, SL_PIR and SL_SP are unchecked). Target curves are not used it the slopes are not optimized.

[Reet]

3.0.1.6 (2026-08-14)

Main

• Target curves of SPL, CTA-2034, GD&Phase and Filter charts are hidden when Optimizer is closed with X button.

I'm not a big fan of this change. I prefer the manual control over which traces are shown. Perhaps a toggle in the options to allow auto show/hide of targets or not would satisfy everyone?

[kimmosto]

3.0.1.6 (2026-08-14)

Main

• Position of splitter bar between Drivers/Crossover/Room tabs and chart area is saved to user.config also when the main window was maximized.
• Target curves of SPL, CTA-2034, GD&Phase and Filter charts are hidden when Optimizer is closed with X button.
• The graphs initially show the target curves used by the Optimizer.
  Exception: Phase target is visualized with ref. axis and listening window target, even though the phase is not optimized.

I'm not entirely sure if the change in the logic for hiding/showing target curves is a significant improvement. Hiding has caused extra work after optimization - especially if the charts were published. I also received some feedback from target hiding, but my interpretation might not be correct.
One option would have been to add new button or menu command for hiding all target curves.

[kimmosto]

I guess it's simple on-axis design with measured phase, and timing of the drivers has been biased manually or automatically; IR peak start to 0 s or so... Relative acoustic distances are adjusted with Z.
Seas has anechoic so actual total to on-axis can be compared to simulation, and Z mm and component values can be adjusted if responses with reversed mid don't match. It's 3-way with dome mid so the risk of high directivity error is quite low.
Many DIYers capture more data, but don't have anechoic to verify anything below midrange. Everyone does what they can and want to do. Some can't, and some others don't want 😀

[Reet]

Seas basic design has not surpassed the skillset of a beginner DIYer. The response data appears to be minimum phase, data is only measured to 60 deg anyway, so CTA-2034 is already lost.

[draki]

I was reading this white paper on the SEAS Storeglimt project.

What caught my attention was the Z-offset value attributed to the drivers on the V-CAD crossover schematics.

Looking at the enclosure, it has a straight front, all the drivers are on the same Z-plane.
Knowing what I know about V-CAD so far, their Z offsets should all be zero..?

What am I missing here? I presume the SEAS team knows more that I do....

[kimmosto]

3.0.1.5 (2026-07-28)

Main

• GD audibility warning and alarm traces in GD & Phase graph modified. See user manual for more information.
• Normalization of group delay traces to cycles removed because in practice audibility threshold is quite constant in milliseconds (not in cycles).
• Value of the selected (bold) curve at the mouse cursor is displayed as interpolated if there are only a few data points.

[technodanvan]

Just a note kimmo, the 'download' link in your signature points to VituixCAD2.

[kimmosto]

3.0.1.4 (2026-06-07)

Main

• Audibility warning and Audibility alarm lines added to GD & Phase graph.

Impulse

• Step and RMS curve smoothing reduced.
• Single IR file export filename changed.

[kimmosto]

3.0.1.3 (2026-05-23)

• Size of color window adjusted to fit all colors without scrollbars.

[kimmosto]

3.0.1.2 (2026-05-22)

Enclosure, Add/Edit driver

• Re max increased to 50 kOhm for piezo transducers.

Convert IR to FR, Impulse response

• Hanning window function renamed to Hann.

[kimmosto]

3.0.1.1 (2026-05-13)

SPL Trace

• Added image conversion to bitmap to 'Paste image Ctrl+V' command. Image formats that can be automatically converted to bitmap are supported.

This was mysterious because pasting e.g. jpeg was working with 2.0 using .NET Framework, but not anymore with 3.0 using .NET 10. Just a small change was needed to get other than direct bitmaps supported without File - Open image command.

[kimmosto]

3.0.1.0 (2026-05-05)

• Added File -> Export -> Filter response of All Drivers.

[kimmosto]

'No interpolation' is primarily designed for:
1) Coaxial 2-ways having both drivers at X,Y,Z=0,0,0 mm and R,T=0,0 deg because measured and simulated exit angles match to all off-axis angles.
2) Professionals who can measure in large anechoic at 2-3 m without time window, keeping rotation center (of mic or speaker) at the same position for all drivers. This enables setting all drivers to X,Y,Z=0,0,0 mm in the schematic because all exit angles match between measurement and simulation. Distance from each driver to mic will change while (vertical) rotation - especially with large constructions so there will be some dense phase wrapping in measurement data. That does not harm summing at the mic, but GD cannot be calculated to off-axis angles. Fortunately it's not usually needed.

One small thing in BartL's screen captures is testing with inverted polarity of mid. That method is not valuable while simulation. Phase mismatch is one possible tool to control direction of main axis usually in vertical plane, power balance and timing (reduce...minimize excess group delay). Inverted polarity method can be used as sanity check to compare timing of simulation and actual speaker. Sometimes mic or speaker stand bends causing error to timing and phase responses if designer forgets to double check actual distance from rotation center to microphone before measurement sequence. Required accuracy is just few millimeters if the highest XO frequency > 3 kHz.

So common people like us keep Interpolation checked. Mid-woofer and tweeter of tiny designs can be measured using the same mic position for both drivers. Interpolation does not help much with tiny speakers because error between simulated and measured exit angles is small. Interpolation is best to keep on that you don't forget it off.

With 15 deg angle step while measurements it's safest to simulate with 15 deg angle step to minimize effect of interpolation due to exit angle error. 5 of 5 measurements within 0-60 deg are probably quite close to simulated 0, 15, 30, 45, 60, ... deg.
Options:

3 of 5 measurements (0, 30, 60) would be close to measurement data if simulated angle step is 10 deg.
0 deg setting in Options uses measured angles only.

[Reet]

When driver coordinates are entered, woofer may be 5.6 degrees angle to the listening location centered on-axis with tweeter at 2500mm. With measurements at 10 degree intervals, interpolation would be required to provide an estimate of the result at 5.6 degrees. Without interpolation, it will simply use 10 degree measurement as-is since it is closest to the required angle.

Most will leave interpolation enabled as it is by default, unless you have some high resolution of angular measurements I don't really see any reason not to use interpolated data.

[BartL]

User manual says:

Still confusing 🤔 read it 3 times.
Still don't quiet understand what would be the correct setting in my case 😕.

The above picture is on axis. 0 degree measurement.
Still, toggling the interpolation on/off shows different results.

[kimmosto]

Listening window (LW) is specified in CTA-2034 to include -30,-20,-10,0,10,20,30 deg off-axis in horizontal plane and -10,+10 in vertical plane. That is one small reason why you could measure and simulate with 10 deg steps. You should also measure 0-180 deg to simulate CTA-2034 parameters for normal full space design.
VituixCAD is very flexible with interpolations enabled. It does not care much about angle step and coverage, but you could follow recommendations (in measurement instructions) and play with default settings to get more accurate results.

[kimmosto]

User manual says:

Frequency responses are interpolated between off-axis angles and planes loaded to drivers when Interpolate is checked. Program selects the closest off-axis angle loaded to driver when Interpolate is unchecked. This could cause some errors and discontinuities, but enables simple tests and projects with few responses only in Directivity chart.

Angle density of simulated and visualized off-axis directions is selected with Angle step list box. Available options are 0, 5, 10, 15, 20 and 30 deg. Off-axis angles loaded to drivers are simulated when 0 deg is selected. Initial value is 10 deg.

Generic 2D is configurable option allowing user to specify how plane and angle value are coded in frequency response filename. Plane keywords define how to distinguish between horizontal and vertical axis. Horizontal axis is selected if keyword of vertical plane is not found in the filename. Search from beginning/end defines whether VituixCAD should start parsing angle value from the beginning of the filename (hor +150 drivername.txt) or the end (drivername hor +150.txt). Angle multiplied by defines how angle value is formatted. For example if 1500 represents 15 degrees off-axis, use Angle multiplied by 100. This option is compatible with ARTA, CLIO in 2D mode.

[BartL]

V2.0.130.1

On the option Tab you have the possibility to interpolate off axis responses.
When I turn this feature on or off I got very different results.
I made measurements 0-15-30-45-60 degrees.
What is the correct setting for this option?





I'm confused 🤔

Do you need some adjustments on the "Listing window" settings to match the steps off the measurements angles? (step of 15 degrees in my case)
What is the meaning of user hor & ver?

[kimmosto]

3.0.0.2 (2026-04-27)

• Built with ApplicationHighDpiMode=DpiUnawareGdiScaled to avoid severe problems with display scaling other than 100 %.

[Reet]

I found no problem so far running Version 3.0 on a Windows 11 VM.

[kimmosto]

3.0.0.0 (2026-04-26)

• First release of version 3.0.
• Requires Microsoft Windows 10 or 11.
• Requires Microsoft .NET Desktop Runtime 10.0

Convert IR to FR

• Charts' background color follows Dark mode setting after session file is opened.

Enclosure

• Enclosure project can be opened with double click also when 'Auto open' is checked, but project list has just one row.

Auto update from 2 to 3 will be activated in a week or two - after some experience how 3 works in different setups.

[kimmosto]

2.0.135.2 (2026-04-25)

• This is presumably the last revision of VituixCAD 2.0.
• Auto update modified to download and install VituixCAD 3.0

[Reet]

I guess it should be some other than MS's AI for converting C# to non-Windows platform 😁

Probably . I hear Claude does quite well for code generation.

[kimmosto]

...all love to hate AI, in some cases it can be employed well to streamline operations, this code conversion may be one place where you could save some time by having code rewritten by a machine model, and then sift through it with a fine comb to ensure its clean and error free.

AI is our change to get application to some other language and platform. VCAD already has some algorithm which is optimized by copilot. It has been unable to produce anything complex and working so far. For example, it tried to get "2nd opinion" for minimum phase extraction. It tried about ten times without luck. In every step it explained that "sorry it is wrong, but this new version works, and this principle is used by REW and some others... blaa blaa". But it did not calculate right so I uploaded working source. After that it was happy and praised my solid approach and was able to make it ca. 20 % faster.
I guess it should be some other than MS's AI for converting C# to non-Windows platform 😁

[Reet]

Windows 7/8 support cycle ended 10 years ago. I'm sure there's plenty of these legacy systems still in service, but it's up to you on what level of support you want to offer to these users. At some point we all need to "get with the times" even if a modern system appears as a lateral or backwards movement.

My personal preference would be a move towards Java or something else that's more OS agnostic in order to provide Linux native installation and the max users too. I see many people moving away from Microsoft these days, however it will still be a while until businesses follow suit. At least, it is starting with some companies reconsidering their Office license agreements.

One suggestion on the Java migration, as much as well all love to hate AI, in some cases it can be employed well to streamline operations, this code conversion may be one place where you could save some time by having code rewritten by a machine model, and then sift through it with a fine comb to ensure its clean and error free.

[kimmosto]

Plan is to update source code for .NET 8.0, convert old practices to new syntax recommendations and rules, and simplify the code. .NET (core) is more modern and significantly faster in some tasks than .NET Framework. Basic work including more than 3000 modifications and code refactoring is already done. It's basically ready for beta testing. This was possible within a week while conversion to Java or something else would require a year or two.

.NET 8.0 will drop Windows 7 and 8 users out. .NET 5.0 would support Win 7 and 8, but I've not yet tested is it possible to step back from 8 down to 5. The latest .NET LTS version is .NET 10 supported until November 14, 2028, and .NET 8.0 is supported until November 10, 2026 so I already have small pressure to go forward.

What do you think?

[kimmosto]

2.0.135.1 (2026-04-10)

Main

• EASERA .etx file format added to Filter response of Driver -export. Sampling rate is special 79587 Hz to cover internal frequency range. Time samples is fixed 32768 so row count is 16385 including 0 Hz. Unit is 'Mag', Re + Im magnitude of transfer function at driver terminals.

Impulse

• Y-axis maximum and span of chart in Frequency domain tab are maintained until Y-axis unit (SPL/gain) changes to maintain temporary scale settings by user.

Enclosure

• Title of Group delay chart changes based on visible curves.

[kimmosto]

Online manual restored. Data transfer limit will be removed today.

[kimmosto]

Just want to mention that the VituixCAD help page appears to be missing today - 404 Not found.

Few days ago service provider informed that my site has exceeded maximum data transfer so I temporarily removed user manual to maintain download service without extra payments. Site uses <3 % of maximum size, but data transfer hits the limit.
Negotiations to balance maximum size and data transfer have started. Situation is that customer service did not understand Finnish or was too busy read my questions.
It's also possible to change service provider or move setup and help docs to somewhere else (shared cloud). Less revisions per month might not help because all - thousands of users would download within the same month anyway.

[Reet]

Hi Kimmo,
Just want to mention that the VituixCAD help page appears to be missing today - 404 Not found.

[kimmosto]

^I need to stabilize Y-scale in Frequency domain tab of Impulse response window anyway so I can look Enclosure too.