VituixCAD v2

[kimmosto]

27" 4K is adequate for main window including schematic and 6 charts. It's a bit too large in my opinion, and separate window for schematic would make working more difficult.
Main window owns speaker and chart data and calculation functions so separation won't happen.

[kimmosto]

My quicky answers for tktran. You know where this refers to.

1) What are main targets for horns / wave guides?
2) Is there alternative solution(s) for horn / wave guide to achieve majority of main targets, and what they are?
3) What is average EDT in your listening room? Is decay spectrum balanced/flat or not?
4) What listening distance you prefer?
5) What acoustic resolution as octave transmission index (of STI analysis) is achieved at typical listening point?
6) How many other speaker+listening room -combinations you have investigated by measurements and what are the results?
7) What are (subjective) consequences if directivity index is 0 dB at LF and 10...15 dB at HF in reflecting environment?
8) Do you prefer DI rise of ca. 10 dB from LF to HF or much less for example max 5 dB?
9) How many significantly different directivity concepts you have evaluated by listening?
10) What coffee roast and ice cream you prefer? Show data, not just obscure opinions.

1) Increase acoustic resolution at far field by increasing directivity below radiator's directive range. Reduce multi-source effects i.e. diffraction without half space application or mandatory requirement to round box edges in full space application. Those two usually lead to some indirect targets/possibilities such as smoother directivity, reduced crossover frequency and simpler passive crossover.
2) Reducing early decay time (EDT) of room acoustics to reduce flutter echo to reduce subjectively significant "reflection noise". The only possible method to reduce EDT is to improve room acoustics. Diffraction can be reduced with half space (flush mounted) application or rounding box edges in full space application. The last one is actually convex wave guide, but kinda opposite to concave horn and deep wave guide.
3) ~200ms, quite flat above bass
4) 220...300 cm is possible in practice. Preference is between those two, depending on location of speakers (3 location options in our living room).
5) Nowadays typical level and spectrum with conventional speaker concepts (without wave guide) is quite linear 0.85@125 Hz ... 0.94-0.97@8000 Hz. Some location-dependence exists because flutter echo depends on locations and cannot be "totally" eliminated for all speaker locations. Best measured in our living room is quite flat 0.89@125 Hz ... 0.98@8000 Hz. Large cardioid bass, passive cardioid at mid, no wave guide at HF, 19m^2 acoustic panels in 25m^2 room area.
6) More than 50 speaker+room combinations archived. Massive differences exist. The worst measured Oct.TI average is 0.78 with large deviation 125...8000 Hz, and the best is very linear 0.98.
7) Listening is focused to frequency range where hearing is the most sensitive for details (high mid...mid treble) and range where acoustic resolution is high due to high DI. It's difficult to follow whole band, composition and arrangement when edges and other HF details of the music is emphasized objectively and subjectively. Listening is not necessarily relaxed.
8) I prefer reasonable rise i.e. conventional speaker concepts without very directive HF or directivity concepts where LF directivity is significantly increased compared DI=0dB with large radiating surface or multiple drivers and unidirectional design.
9) Not full range omni-directional concepts, but close to everything else tested also at home. For example full range dipoles, dipole low+cardioid mid...high, full range cardioid, omni low+dipole mid...high, omni low+cardioid mid...high, omni low+cardioid mid+horn high, cardioid low+horn mid...high, line low+line high, line low+horn high.
10) 2½...3. Raspberry blueberry vanilla.

[JonMarsh]

My favorite monitor setup for VituixCAD is an LG 43UD79-B 43” 4K monitor, setup with 125% font scaling. They can be had for around $600, and though the color gamut isn’t adequate for photography, they’re clean off axis and great for CAD and documentation work.

[tktran]

Thanks for your answer Kimmo.

I recently bought Kali IN-8 for evaluation: measurements and brief listening; and concluded it was amazing product for what looks like a BOM of €50.

KH150 looks like a competent monitor without any gross errors.

[kimmosto]

100000 downloads in 2022 exceeded

[tktran]

Kimmo,

I would like to request a feature:

to be able to update/adjust the baffle AFTER it is created. Eg. Initialise baffle of dimension a x b mm, then drag/drop baffle corners/edges and see effect on diffraction.

[kimmosto]

Initialise baffle of dimension a x b mm, then drag/drop baffle corners/edges and see effect on diffraction.

That's how it has been since the first version.

[tktran]

Yes of course! And I have used this feature previously, I wonder why I had a brain fart. Apologies.

Is there a way to adjust edges eg. drag and drop the width or height of baffle?

[JonMarsh]

100000 downloads in 2022 exceeded

Congratulations!

[kimmosto]

Facebook group created. Let's see is it just extra trash to clean some day...

https://www.facebook.com/groups/454942413386350

I may post something also to twitter with vituixcad as @kimmosaunisto.

https://twitter.com/search?q=VituixCAD&src=typed_query&f=top

[kimmosto]

Is there a way to adjust edges eg. drag and drop the width or height of baffle?

This could be a bit better solution especially if number of corners is >4:

2.0.92.0 (2022-11-23)

Diffraction

• Set origin (0,0) command added to context menu of baffle image. Ctrl + mouse click is still available.
• Baffle width and height can be adjusted with text boxes after baffle is created with New button. Movement of corners is relative to selected origin (0,0).
• Baffle width and height are updated to text boxes after corner is moved with mouse or arrow keys or text box.
• Data type of location coordinates (x, y, width, height) changed from integer to floating point to avoid rounding errors in corner positions when baffle size is adjusted after initialization.
• Actual corner count and driver count saved to baffle project file.

[Nordo]

Currently using v2.0.92.0.
Have a problem with the Merger Tool.

The Merger Tool is basically divided into three sections - "Low frequency part" at the top; "High frequency part" in the middle; and the SPL graph at the bottom.
I want to increase the size of the SPL graph as I'm having problems differentiating between the graphs (near field, port, and windowed far field).
I can reduce the size of the "Low frequency part" but the "High frequency part" is staying full size, and hogging most of the screen.

Any ideas?

Also is there any hints to help achieve the best merge?

EDIT : Have now realised that the red graph line is my two Low frequency parts (near field measurements of driver and port) compiled into one graph.
Which means I can switch off the two separate near field measurements (green lines) which definitely makes reading the graph lines easier.

Still not too sure where to recognise the best place is to transition the two curves.
My gated window of the far field was 12ms, so the far field graph extends down to 83.3Hz.

BTW, I'll ask another question while I'm posting.
Should you trim out all the additional text REW adds to the start of a frequency text file?

[kimmosto]

It's possible to zoom in with frequency limits and adjusting Y scale with mouse wheel and Ctrl + mouse wheel when mouse cursor is closer to left Y scale. Minimum span is 10 dB.


Anyway, I could fix height of LF part and move splitter bar between HF part and graph. That would allow larger chart.

[Nordo]

Thanks Kimmo.🥂👍
I edited my post before I had noticed that you had already replied.

[Reet]

Still not too sure where to recognise the best place is to transition the two curves.
My gated window of the far field was 12ms, so the far field graph extends down to 83.3Hz.

far field window will define the low frequency extension and resolution of the far field measurement. For near field limitations you will find a calculator available under auxiliary -> near field. When done correctly you should see significant overlap of near and far responses given the large window used, making splice selection and easy choice.

[Nordo]

far field window will define the low frequency extension and resolution of the far field measurement. For near field limitations you will find a calculator available under auxiliary -> near field. When done correctly you should see significant overlap of near and far responses given the large window used, making splice selection and easy choice.

Reet Thanks.
Staying within the near field and far field measurements limitations, I'm just trying to get the best/smoothest compromise with my splice location.
But my best location seem to be just before the near field limit.

[Reet]

I guess all that work to get a 12ms window was a waste of time then, huh? You’ll need to share your work to get any more of a comment than that.

[kimmosto]

2.0.93.0 (2022-11-26)

Impulse response

• Added LisWin SPL MP - listening window average SPL as minimum phase version to Signal to show list box.
• Added Total SPL MP - total SPL to reference angle as minimum phase version to Signal to show list box.
• Added Freeze Y checkbox for skipping automatic scaling of vertical (Pa/V) axis.

Merger

• Splitter bar between Low frequency part and High frequency part moved below High frequency part to enable higher graph area.

Calculator

• Splitter bar added between B response and chart to enable higher graph area.

[kimmosto]

Very smooth window functions such as Blackman-Nuttal allow some reflections inside time window without severe problems. Time window could be for example two times longer than arrival of the first reflection.
Sharp windows such as Rectangular should end where the first boundary reflection starts to lift ETC curve. And then we have several window functions between those two extremes. For example Tukey 0.50 can end close to peak of the first boundary reflection.


Another problem with window functions is that they could corrupt magnitude response. Sharp window functions tend to add small over-shoot to frequency response just above HP slope. Very smooth window functions such as Blackman-Nuttal, Hanning or Cosine don't add hump, but they could smooth frequency response quite...too much at mid-range. If window function is for example Tukey 0.50, good merging frequency is just above small response hump, and of course below maximum frequency limit calculated from diameter (indicated in red). Possible merging range could be very narrow with large (12"...18") woofers if far field is measured indoors with short time window close to 4 ms. Ground plane measurement helps in that case. Anyway, Tukey 0.75 is one the best compromises between over-smoothing and over-shooting.
Few examples about response humps:

[kimmosto]

Few examples about merging range - how it could narrow with larger woofers. Usually merging is easy. Few tips: Remember to simulate diffraction response to 5-10 meters to apply full baffle loss with conventional boxes speakers. Small pressure losses could exist at mid-range with near field measurements so LF scaling in dB should not be too high.

4"midrange closed:


5.25"midwoofer vented:


6.5"midwoofer, 2 passive radiators:


7"midwoofer closed:


12"subwoofer closed:

[kimmosto]

2.0.94.0 (2022-12-02)

SPL Trace

• Added Manual checkbox to trace (or modify automatically traced curve) manually point by point.

[kimmosto]

Diyaudio's moderator banned me for criticizing FPGraphTracer as crap that needs some special protection and advertising from moderators. That was rude of course, but moderators seem to promote and support bad and limited and dated design methods and tools. Especially beginners are "encouraged" to use whatever they find first either accidentally or from a list of design tools including everything possible without much criticism, intelligence and modernity. I am not fishing for new users for VCAD. Just feeling sorry for users who get stuck with bad tool (such as FPG...) because "authorities" are over-polite chickens with some own agenda.

Few comments also about XSim. Moderator (AllenB) says "I'm interested in seeing Xsim's continuation and I hope that if needed the project finds a maintainer". Many years ago bwaslo provided some parts of XSim's source code for me to use in VituixCAD: coordinate system for components, node numbering, pin naming, network parsing, filling of (sparse) matrix with admittances and matrix solver. VCAD is still using close to same coordinate system, node numbering, pin naming and and matrix filling. Network parsing is simpler due to differences in wires, and matrix is dense with different solver. So VituixCAD is the "continuation" and I'm the "maintainer" in practice at least according to my interpretation. All features of XSim are there, but also 10PI times more. Dreaming about XSim which would just duplicate some small group of features does not make any sense.

So goodbye diyaudio for good.

[Reet]

That's a really poor move from DIYAudio, in particular Allen. Your criticism was quite polite honestly, certainly nothing more than "thanks for your opinion" and move on was warranted in my opinion. It's just a graph tracer, and not a great one, nothing to be up in arms over. It's unfortunate that criticism is so poorly received, but such re-occurring nonsense from _Force seems to have no consequence (or maybe it does behind closed doors, but clearly not a bannable offence).

I honestly don't know why people still use Xsim. Must be the basic feel for newbies since it only has a dozen or so buttons to choose from.

[tktran]

Disappointed to hear that you were banned. The SINAD of DIYAudio is getting lower and lower.

The problem with DIYAudio is that some of the mods are not very progressive. Stuck in their old ways of "designing speakers without measurements" or "use WinISD". Geeze, shall I take out my slide rule or abacus as a warm-up?

AllenB's own posts are often lacking in constructive detail, off-the-cuff, or flippant. At worse, bordering on trolling. Who moderates the moderators? I've gone to ignoring his post as much as I can. I mean he probably have some experience and old knowledge which makes his cryptic responses all the more frustrating.

Tell us which non-English forums you visit Kimmo, and I'll fire up the ol' Google Translate...

[kimmosto]

Your criticism was quite polite honestly

I wrote two messages, and the last one in "Favorite Threads and Posts..." on Multi-Way wasn't polite with "crap" word and direct criticism about moderators.
Anyway, question is why bad tools need more attention by the moderators than good tools. Of course everyone including myself has own subjective and probably biased opinion what is good and bad. Maybe VituixCAD is "too featured" and complex large forest compared to some simpler apps, but that alone does not make individual feature/tool any worse.

[Nordo]

Question regarding the Room Tab.
The default absorption of the reflective surfaces is 2dB.
Is there a reference or data base where these reflective properties can be refined?
e.g drywall on timber frame; drapes in front of full height glass sliding door; rug on concrete floor; etc.

Currently my simulated in-room response is so bad that I can't use it in my crossover design.

[Nordo]

Question regarding the Frequency Range in Optimizer.
Should be range be set for just the crossover range - e.g. 3000Hz to 5000Hz?
Or should it be set to the full range of your target curve?

When I run Optimizer, it runs wild and appears to ignore my target curve.
Even though the target curve is very close to my unoptimized crossover SPL.

[Reet]

Question regarding the Room Tab.
The default absorption of the reflective surfaces is 2dB.
Is there a reference or data base where these reflective properties can be refined?
e.g drywall on timber frame; drapes in front of full height glass sliding door; rug on concrete floor; etc.

Currently my simulated in-room response is so bad that I can't use it in my crossover design.

Unless the speaker design is for permanent installation, the room should not be considered for crossover design. Whole point of measurement process is to remove the room from the equation. Use in-room response on the power & DI chart for performance in a typical room relating to the crossover design.

Once complete and located in your space, you may apply some EQ to help the room response if you like, use moving mic method with REW to gather in-room response average of listening location and apply EQ from there.

Room tab in VituixCAD honestly isn't of much use other than to identify obvious relection locations based on speaker and listener location to nearby surfaces. My opinion is that you get greater insight of the room using the room simulation in REW.

[Reet]

Question regarding the Frequency Range in Optimizer.
Should be range be set for just the crossover range - e.g. 3000Hz to 5000Hz?
Or should it be set to the full range of your target curve?

When I run Optimizer, it runs wild and appears to ignore my target curve.
Even though the target curve is very close to my unoptimized crossover SPL.

Frequency range should be set to the range that you want the optimizer to target. For example, for system axial / listening window 100Hz - 10kHz may be appropriate, power response maybe 400Hz - 10kHz. If using for high pass or low pass filters, limit frequency range to a couple octaves above and below the filter knee. Targeting 20Hz-20kHz for a tweeter high pass at 2kHz will be problematic.

[kimmosto]

Room tab in VituixCAD honestly isn't of much use other than to identify obvious relection locations based on speaker and listener location to nearby surfaces.

I don't clearly recall why Room tab was added. In-room response as a sum of direct sound and individual first order reflection "rays" from floor, wall and/or ceiling is different view to result of Early Reflections; ER hor, ER ver, ER total and ERDI. Primary design parameters especially with small conventional speakers are spinorama responses in Power & DI chart, but designer can quickly check how those curves look as single sum of direct and mirrored reflections.
CTA-2034-A spinorama lacks understanding about floor gain which is one parameter to consider while designing tower speakers having woofer(s) very close to floor. It's ca. 3 dB using DI theory, but Room tab provides pressure theory as a second opinion for estimation how much LF can be dropped in anechoic response. But generally Room tab is quite invaluable.

I use Driver offset group to check is listening axis at proper level. If elevation (Y mm) of driver instances is not good, this is the easiest place and method to move all at the same time.

[kimmosto]

Tiny tweaks done to the latest rev.
SPL Trace

• Added Magnifier checkbox to show magnifier continuously (press and hold Shift key to show temporarily still exists).
• Frame of the magnifier shows color at mouse cursor while tracing.

---

[Nordo]

Reet @kimmosto
Thanks for your replies guys.
I was only using the Room tab because it was there, and because Room Response settings/preferences is available in Optimizer and Preferences.
I'll leave any reference to room response and ER out of my design.
Kimmo makes a good point regarding floor gain.
My design is transmission line towers, wher the tweeter (mid-range actually) is approx 1100mm above the floor; the woofer is 800mm above the floor; but the TL outlet is at floor level. All having completely different early reflections, especially from floor and ceiling.

On another point regarding my question on in-room surface absorption, surely the absorption (e.g. 2.0dB) is frequency dependant? So how can you put a fixed value to it?

[kimmosto]

So how can you put a fixed value to it?

VCAD is not room acoustics and material simulator. Frequency response of boundary would be just one extra parameter user would have to draw from his sleeve.
P.S. Simulator I programmed in the end of 80s' had two attenuation values (for 20 and 20k), but reflection simulation is not so important anymore because spinorama is more universal and focuses to speaker itself.

[Reet]

Reet @kimmosto
Thanks for your replies guys.
I was only using the Room tab because it was there, and because Room Response settings/preferences is available in Optimizer and Preferences.
I'll leave any reference to room response and ER out of my design.

Optimizer "in-room response" is in reference to PIR (orange) on power & DI chart, not room tab. Yes, you should consider this response in your design optimization.

[Nordo]

Optimizer "in-room response" is in reference to PIR (orange) on power & DI chart, not room tab. Yes, you should consider this response in your design optimization.

Aha, I thought the data that PIR used was based on the information you fed into the Room tab.
Thanks Reet.👍

[Reet]

Just a couple notes on REW as it relates to use with VituixCAD, the latest early access 5.20.14ea12 build of REW includes a a few more windowing functions to align with the IR processing features in VCAD: Tukey 0.5, 0.75, and cosine is now available, among other UI improvements and features.

https://www.avnirvana.com/threads/v5-20-14-early-access-build.11154/

[kimmosto]

I could try to update measurement instruction for REW in a month. At least new features related to reference channel and time windows.

[kimmosto]

2.0.95.0 (2022-12-07)

Main, Directivity Polarmap

• Visibility of contour lines moved to submenu as Show.
• Contour line step is adjustable: 1, 2, 3 or 6 dB.
• Number of contour levels is adjustable: 1, 2, 3, 6 or 10 lines.
• Top level of contour lines scaled automatically when chart is not normalized.

[kimmosto]

My previous message was classified automatically as a spam and needs approval by a moderator until it is shown. This is not the first time within a month. Possible problem is that I modified message quite soon to fix typos or add images. Upgrade posts are not very important, but that kind of spam filter is too sensitive imo. Corrections are best to do right away without looking time to avoid spam trap.

[Reet]

Agreed. I had this problem a little while back, other problem is moderator didn't seem to review the post and approve it, I simply re-posted the same information a day later.

In any case, the update info was spotted on Facebook. Welcome change to be able to adjust the contour step, though I don't really see the benefit in limiting the number of contour lines.

2.0.95.0 (2022-12-07)

Main, Directivity Polarmap

• Visibility of contour lines moved to submenu as Show.
• Contour line step is adjustable: 1, 2, 3 or 6 dB.
• Number of contour levels is adjustable: 1, 2, 3, 6 or 10 lines.
• Top level of contour lines scaled automatically when chart is not normalized.

[kimmosto]

I don't really see the benefit in limiting the number of contour lines.

Drawing contour lines is graphical loop where program scans all pixels in the bitmap and drops a pixel if color hue exceeds contour level in X or Y direction. So limiting up to 10 levels is to maintain performance especially as zoomed in. One possible usage for 1-2 lines is to visualize beam width at -3dB or -6 dB or both, but nothing else. Limiting up to 6 levels with 1 dB step could be important when designing HT speakers. Smooth balance within wide listening sector is an advantage. This change was requested by a manufacturer, but hopefully it's valuable also for DIY.

[Reet]

I do like the contour lines, it makes for a much clearer polar map IMO. Another option for clarity would be to limit to solid colour steps instead of continuous gradient and contour lines. Here's an example from a quick image search:

[kimmosto]

^That is one good option. It works well with 3 dB steps when SPL span is not very wide. I've not tested how many levels display and eyes can distinguish but 1 dB step with 40 dB span is probably quite close to gradient fill. Polarmaps/heatmap has one problem. Level steps / contour lines are not fact. Mostly just results of interpolation because they usually exist between measured/simulated off-axis angles. Directivity charts showing individual frequency responses (line chart, waterfall / area chart and surface chart) don't require any interpolation for graphics. Just for simulation in acoustical domain.

[kimmosto]

2.0.96.0 (2022-12-11)

Merger

• Added optional 'Diffraction response X mm' text box, open button and clear button to High frequency part. Baffle effect response simulated to actual measurement distance of far field High frequency responses is selected into this text box.
• 'Diffraction response' label in LF part renamed to 'Diffraction response 5-30 m'. Baffle effect response simulated to the longest ever possible listening distance is selected into this text box - just like before.
• Button for starting Diffraction tool removed from LF part

[kimmosto]

Previous may need some elaboration. If measurement distance of time-windowed far field responses is short for example 1000 mm, measured responses include less baffle loss and less baffle step hump than at the final listening distance for example 2.5 m. The latest version of Merger tool includes possibility to compensate short far field measurement distance by multiplying far field responses in HF list by relation between 'Diffraction response 5-30 m' and 'Diffraction response 1000 mm'. The same in dB: difference between blue curve (30m) and red curve (1m) is added to all far field responses in HF part. Compensation ends when red and blue curve intersect the first time above 3500 Hz. Compensation trick is not perfect because affects also to off-axis responses, but hopefully reduces risk of too high bass level and too low mid level to on-axis in SPL graphs while simulating XO. Feature is optional so you can leave 'Diffraction response 1000 mm' empty if possible small error is not a concern.

In the following example difference between 1m and 30m is ca. 0.5 dB within typical transition range, and a bit less at baffle hump.