VituixCAD v2

[kimmosto]

For myself, these cases are usually at the frequency extremes, so perhaps peak normalization from 200-8kHz would work well, and peak response outside of that frequency range can be shown towards white spectrum.

Peaking of top octave was probably the reason why normalisation was not originally done, but negative side effect is that we need to adjust generator's voltage to get mid-range close red / reference level (any major grid line).

The cheapest trick to ignore top octave is to look graphs within 20-10000 Hz. Peak is scanned within visible frequency range so HF peak alone does not drop mid-range. But that is also extra temporary adjustment such as generator's voltage.
Fixed range for normalisation is possible and very easy to do. One possible limit is that one could want to evaluate single HF or LF driver such as super-tweeter or sub-woofer without normalisation to reference angle.

For example peak scanning 40...10000 Hz with (equalized) huge peak at the top octave. I could probably live with that...

[Reet]

I like the peak amplitude normalization for the polar map. This is beneficial for the contours, as it ensures that 3dB contour steps are in 3dB increments from peak 0deg amplitude, where previous it appeared arbitrary. It also allows for adjustment on y axis of SPL and power & DI chart without making the polar map look out of place. Thanks!

The edge case would be some instance where some resonant mode or rising response should be shown as "above" the normalized value, which would normally appear white. White colour at the top of the palette however will never occur in this instance, instead the remaining response will be shifted down the scale. I'm not sure how that would be best addressed. For myself, these cases are usually at the frequency extremes, so perhaps peak normalization from 200-8kHz would work well, and peak response outside of that frequency range can be shown towards white spectrum.

[kimmosto]

2.0.114.0 (2024-06-25)

Main

• Added 'Klippel palette' option for directivity Polar map. Activated from context menu of directivity chart -> Contour lines -> Klippel palette.
• Peak level is normalized to red (dark red with Klippel palette) also while 'Normalized' is unchecked in context menu. Colors stay constant regardless of sensitivity and SPL max setting of SPL and Power & DI charts.
• Aspect ratio of directivity Polar map follows W x H in px setting in Options. Height is not forced with dB/dec setting though selected.

Main, Options

• Added 'CTA-2034-A power weights' checkbox to 'Power response & DI calculation' group. Power response is calculated using angle weighting factors with constant angle step of 10 degrees. Factors for angles between 10 deg steps specified in the table are calculated with spline interpolation.
  Note 1: Weighting factors are calculated with traditional integral sine if 'CTA-2034-A power weights' is unchecked or angle step of simulated off-axis angles is not constant.
  Note 2: CTA-2034-A table with 5 deg angle step is ignored (due to bugs) though simulated angle step is 5 deg or less.

Impulse response

• Initial filename of exported impulse response files does not contain crossover variant (var1, var2, ...) anymore.

Normal polar map palette.

Klippel palette. Contour lines are less transparent than earlier to be more visible with darker red.


CTA-2034-A power weights vs. default power calculation using integral sine. Difference is almost invisible.

[mv8]

Poll. Are you happy with XO variant S and R buttons - how they work? E.g. do you prefer that program would not save variants automatically when jumping to some other variant with R button i.e. clicking correct or any S button is required before jumping to some other variant? (project with one variant only would not require S button to save the project).

Single company is asking that kind of functionality, but I have quite high threshold to do changes to existing logic. I think variants are like pages in document editor. S button creates a copy of current page, and R button just changes current page without requirement to click or confirm anything else. Only problem at the moment is that Undo buffer is cleared when variant is changed (to save memory and simplify code).
For example LspCAD has different functionality, but it's difficult and illogical imo.

Hi Kimmo.
The ability to save slots with different filter variations is very useful, but one thing I find really annoying.

When designing filters, I use EQ APO at the same time. When exporting IR files for each driver, VituixCAD writes the individual Variant for that Var cell in its name. This is a big inconvenience for me, because every time I export a different filter scheme from a different Variant cell, I have to manually rename the files in the configuration for EQ APO.

If it were possible to make it so that the IR export saves the same file name, without the Var ending, then it would be possible to switch and export between crossover filter variants without editing the configuration in EQ APO, and this gives the possibility to listen to the saved filter cells in almost real time.

[kimmosto]

2.0.113.3 (2024-05-18)

Main, Crossover tab

• Component/parameter value stepping modified.
  LCR values using 5%/E12/E24/E48 snap are detected from unit instead of component category=passive.
  Added more stepping options with Ctrl and Shift key.
  Snap group not disabled while modifying other than passive components/blocks.

Main, Tune block window

• Added 'LCR snap' group: No, E12, E24 or E48.
  Selection saved to user settings.
• Block attribute value stepping modified.
  LCR values using selected snap are detected from unit.
  Added more stepping options with Ctrl and Shift key.
• Calculated LCR values of inserted blocks are using snap selected in Tune block window.
  Note! Optimized LCR values are still using snap selected in Optimizer window.

Enclosure

• 'Copy as xml', 'Delete rows', 'Duplicate rows' and 'Hide rows' commands disabled if whole rows are not selected.

[Nil L]

Poll. Are you happy with XO variant S and R buttons - how they work?

Yes.

[HTDT89]

Poll. Are you happy with XO variant S and R buttons - how they work?

Generally, yes.

re: auto-save, an optional warning about losing changes (like opening a different project without saving) probably would be easiest way to address the customer request. And after seeing it 21 times, user auto-saves before switching, right?

A visual hint that unsaved changes exist might help, e.g. R2*.

Not important, but I wish XO variants behaved more like browser tabs. Ctrl+PgUp/PgDn and Ctrl+1..8 to switch would be great.

[draki]

No issue with the current form. Having simply accepted as it is, after some practical use it becomes a natural action.

[Reet]

File menu, save project as ...

[JMB13]

I have found these buttons a little confusing at times. I will occasionally bring up one option and work with it and then click on another option and lose the original option of the first. I wonder if there is a way to have it in a cache so that one can work with an option and return to the original after doing so? Maybe a manual save option to temporary back-up cache that can be recalled after "playing" with alternatives? Just thinking out loud here. Thanks so much, Jay

[Reet]

I've no real issue either way. Many times when creating a new variant I want to start fresh, so the only extra tedious task is to select all and delete if I didn't want a copy of the existing crossover variant. Very minor inconvenience not worth talking about IMO.

The improvement I would have in mind would be to leave the functionality of S and R buttons as-is, but pre-populate all 8 variants with blank crossover pages, so you can start fresh if desired by simply recalling an unused variant, or S button can still be used for copy function. Alternative would be remove S button completely in this case, and user can copy/paste if desired.

If the intention would be for the user to hit the S button to save a particular variant before recalling another, otherwise changes made are lost, I am not in favour of that. It would require additional prompt "would you like to save changes?" on every variant change, which I would mostly find annoying.

[kimmosto]

Poll. Are you happy with XO variant S and R buttons - how they work? E.g. do you prefer that program would not save variants automatically when jumping to some other variant with R button i.e. clicking correct or any S button is required before jumping to some other variant? (project with one variant only would not require S button to save the project).

Single company is asking that kind of functionality, but I have quite high threshold to do changes to existing logic. I think variants are like pages in document editor. S button creates a copy of current page, and R button just changes current page without requirement to click or confirm anything else. Only problem at the moment is that Undo buffer is cleared when variant is changed (to save memory and simplify code).
For example LspCAD has different functionality, but it's difficult and illogical imo.

[kimmosto]

2.0.113.0 (2024-04-13)

Power dissipation

• Added Ptot in watts i.e. total power dissipation to tooltip of driver, resistor, coil and capacitor traces. Calculated as power average within simulated frequency range of 5-40k; sum of power values divided by number of simulated frequency points. Power should be selected in View group to show Ptot.
• M-Noise peak response updated.
• M-Noise RMS response updated to produce crest factor and power dissipation more compatible with current Music-Noise.wav files.

Main, Options

• Added 'Generic -a12' to DSP list. Same as 'Generic', but biquad coefficients a1 and a2 are multiplied by -1.
• Added sample rates: 88200, 93750, 352800, 384000, 705600, 768000 Hz.

Auxiliary

• Added sample rates: 88200, 93750, 352800, 384000, 705600, 768000 Hz.

Convert IR to FR

• Added sample rates: 93750, 352800, 384000, 705600, 768000 Hz.
• ETC smooth maximum increased from 8 to 32 samples.

Enclosure

• 'DSP system' combo box removed from Filter tab. Transfer functions are calculated using DSP settings in the main program.

Impulse response

• Added sample rates: 352800, 384000, 705600, 768000 Hz.
• ETC smooth maximum increased from 8 to 32 samples.

[kimmosto]

As a feature request, I think it would be nice to have an option for log scaling of Y axis for impedance charts.

Chart class has nothing ready for log Y scale so that wouldn't be too easy fast.

[Reet]

As a feature request, I think it would be nice to have an option for log scaling of Y axis for impedance charts.

[kimmosto]

Here is my comparison to LspCAD 6.65 Pro. Seas W21EX002 in 35.1 liters, BR, port 7x26.6 cm. About the same Q-factors etc.

Original


Re changed 6.4 -> 3.2 Ohms, BL changed 9 -> 6.505, without autocompute or crosscalc.


Added external resistance of 3.2 Ohms


Inductance simulation should be on in LspCAD 6 to get correct result


Both programs behave as expected with external network.

[Snickers]

I don't understand why you play with parameters and mix them with external circuit.

Not sure I would go into too much detail on that, but it does indicate that something strange is going on. I consider doing an identical simulation in LspCAD for comparison.

[kimmosto]

I don't understand why you play with parameters and mix them with external circuit. The best method to verify is calculation okay with external passive filter components (Cs, Ls and Rs) is to export SPL and Z responses without filter components, load responses to Drivers tab in the main, build test network to Crossover tab, export Driver's frequency response, load it as overlay to SPL chart in Enclosure and finally set up the same filter components and values to Filter tab. Result is exact match at the moment so calculation is correct at least with single driver. Two examples.
Rs=10 Ohms:

Cs=470uF, Ls=2.2mH (0.1 Ohms), Rs=5 Ohms:

Some old versions handled Rs as addition to Re in some calculations, but not anymore. Rs is pure external component which drops voltage at driver terminals Ze/(Rs+Ze), calculated with complex numbers. Very simple and correct.
Crosscalc prioritizes fundamental parameters. Locking makes possible to create impossible combination of overlapped parameters so it's highly unlikely that I would add it.
Row duplication works though it does not inform if whole rows was not selected. Rows should be selected using row header (gray cells on the left).

[Snickers]

I may have found another bug.



So I put a driver in a BR enclosure. Then I modofied the driver to have 2 ohms less Re, and adjusted the Bl back to its original value to see the values for Qts and Qes be updated. Then I put a 2 ohm resistor in series with the driver, so the total serial resistance is back to its original value. This is like taking just 2 ohms of Re and move it just outside the coil. It should give the same response. We should not see a dip like that at 160Hz, neither a raise in pass band sensitivity like this as the circuit is the same.

Either, I have done a huge mistake, or there is a pretty significant bug somewhere in here. I do believe we got a different result in the previos version (where Rg was just next to the input voltage), but my memory may also be playing with me a bit.

While testing this, I also found it hard to clone a driver. There are some menu choices for this, but they did not seem to work. I also find it hard to alter parameters using cross calc as they can not be locked, so I need to figure out in which order they are altered so I can change them back manually.

[JonMarsh]

The Earthworks M30 is a great mic in my experience, highly recommended- of course, it should be, considering the price.

For enclosure interior measurements, I strongly recommend checking detailed specs, and proceeding cautiously with drive levels, as SPL in cabinet is high. Mic's like the ECM8000 and Dayton EMM-6 have maximum working levels around 120-125 dB.

[kimmosto]

Did you receive my email?

Yes, sorry about delay. I have CLIO MIC-01, Earthworks M30, Sonarworks Xref 20 and probably still one very old but unreliable ECM8000. I don't usually do own distortion measurements so no truths or recommendations to share. I would probably try Earthworks M23. My M30 individual does not require calibration. It should tolerate quite high pressure, but this is just guessing.

[tktran]

Hello Kimmo,

Did you receive my email?

[kimmosto]

how are your adventures with Java going?

Not well. No progress since 2023-08-09.

[Reet]

Thanks Kimmo!

By the way, how are your adventures with Java going?

[kimmosto]

2.0.112.0 (2024-03-24)

Merger

• Added 'Delay mm' column to LF response list for travel difference to main/cone radiator on front baffle at typical listening distance (2-4 m) on-axis.
• Directivity to 90 deg is added to LF radiators located on other than front panel i.e. BS (baffle step) checkbox is unchecked. Directivity is simulated for ideal circular piston with 'Diam mm'. Support for rectangular surfaces might be added later.

[kimmosto]

About a week ago I already tested adding delay (in mm) to all rows in LF near field response list. That could be quite adequate addition to Merger tool assuming that directivity information included in far field measurements is "good enough" also for LF part. Entered delay would be travel difference between port and main/cone surface to typical listening position at e.g. 2-4 m.
Adding simulated directivity of radiating surface to 90 deg for top, bottom, side and rear ports/passives would be another helpful addition. That can be significant especially with passive radiators. Effect can be calculated using existing 'Diam mm' column (when BS is unchecked), though ports can be rectangular.
Baffle step exists on-axis when radiating surface is in front panel, but very close to zero on top, bottom, side and rear radiators. Existing BS checkbox takes care of that.

I will add those two features to the next revision. Using main program is a bit too complex so let's try simpler one first.

[Reet]

Time locking of near field measurements takes care of internal delay compared to main/cone radiator

Thank you for your response. I understand, that internal time of travel from driver cone to port exit is accounted by locking the timing, however I am thinking about the additional time of travel from port exit back to the driver location once the signal leaves the cabinet, so near field is represented as single point in space measurement. When measuring driver and port exit individually, physical location of mic may differ by 0.5m or more on a large cabinet, so this is what I was expecting to address with a simple additional delay, in the same sense that Hornresp includes an "Acoustic path length between outputs" in its calculations.


It makes little difference in <100Hz range, but as we know there can be significant output up to 500Hz+ that affects overall response through the merge frequency range. An example of some data provided to me by another user for a TL speaker. Here, the delay value of the TL output >200Hz has significant impact on the combined result, so just trying to confirm that the normal locked timing process is providing the expected result.


It sounds like I could take a step further and process each near field response individually with diffraction and delay through the main program if I want to go the extra length on this process. Thanks for this idea, I will explore a little more.

[kimmosto]

When processing nearfield measurements, for woofer nearfield and port or TL exit, does it make sense to incorporate some delay to the port output if it's located a significant distance from the woofer? ...

Time locking of near field measurements takes care of internal delay compared to main/cone radiator, but as we already know, that's the easiest part in this merging puzzle. Significantly better summing of near field responses would require directivity/baffle loss simulation of each radiating surface, location X, Y, Z, rotation R and tilt T. With this data LF near field measurements could be transformed to far field, and then merged to far field HF measurements. Merger tool can do the last part but nothing more. Diffraction tool can simulate directivity for individual radiators i.e. convert ports etc. to far field with off-axis, and main program is able sum dual plane far field data with X, Y, Z, R and T parameters. I have done it few times to reduce some errors, but the procedure is not very easy. All those features integrated in Merger tool would be nice, but it's quite big change and probably more difficult to understand and operate.

[kimmosto]

2.0.111.4 (2024-03-18)

Main

• Parameter min and max limits read from crossover variant before the value to prevent limiting between default min and max.

Enclosure

• Total SPL max trace in SPL chart limited with real power of driver instead of power to Re. Note! Result depends on 'Show effect of inductance' setting.
• Max length of vent increased to 9999 cm.
• Max diameter of vent increased to 112.8 cm, 9993 cm^2 as area.
• Max number of vents increased to 50.

Convert IR to FR

• Output file format selection changed from radio buttons to list box.
• Added LMS output file format.

[Snickers]

Max port length of 500cm while still simulating longer ports.

I was simulating a huge infra bass subwoofer. When I lower the tuning or increase the port diameter to the point where the length passes 500cm, the simulation seems to still work as intented, but the port lenght shown on screen never passes 500cm. As this equals a pipe resonance of 34Hz, it is not a big deal, but still what is shown on screen is incorrect. Also, with a quarter wave calcelling path, a 5 meter port could be useful up to just above 50Hz, so some might look for a solution like this.

[Reet]

When processing nearfield measurements, for woofer nearfield and port or TL exit, does it make sense to incorporate some delay to the port output if it's located a significant distance from the woofer? Physical distance from port exit to woofer nearfield location can sometimes be in the range of ~1m. I've always processed the port and woofer nearfield together in the IR - FR tool, pressing "near" on the woofer impulse, and port output is always very slightly delayed anyway, but perhaps there could be some benefit to providing additional delay to the port output if the physical distance is significant? For something like a TL, there is often still significant output in 200-500Hz range, so the phase / delay of the response can make a significant difference in the merged result.

It can be done of course by adding delay in the calculator tool, however if this process makes sense as "common practice", perhaps it would be a good addition to the merger tool, to allow individual delay adjustment of each response in the "low frequency" portion.

[Quza]

Small bug report:
When switching between crossover variants VituixCAD resets the Z position of a speaker to the default limit of 2000 if the value entered was bigger than this.
Reproduce by:
-increase Min/Max values to 5000
-enter Z 4000mm
-switch to different crossover variant and back
-Z is 2000mm again

This isn't a huge deal for designing loudspeakers, only a little annoying when simulating subwoofer arrays

[Nil L]

kimmosto,
There is a suggestion about the space to the right of the crossover cirquit. Now it is possible to disable one graph out of six. After disconnecting, the space remains empty. If you turn off 4 graphics, the remaining 2 can be placed one above the other. Then the detail of the remaining graphs will increase. There will be 2 times more horizontal space and 1.5 times more vertical space. It is rare that you need to see all 6 charts at the same time. And two at once very often. It is possible that three at once is even better, but it is not clear how to arrange them.

[Snickers]

kimmosto


I find these drawings extremely informative in regards to the end correction function. They seem to fit rather perfectly with practical testing.

Do you think these could be added to the user manual?

[JonMarsh]

As a former college of mine was fond of saying, "I'm in violent agreement with you!"

[kimmosto]

I found it worked "well enough" for a pair of 10" passive radiators I had without documentation.

Sometimes solver is able find very good match, but it may require solving of extended impedance parameters too. Here is an example with Purifi PTT6.5X04NFA with two passive radiators. So we can simulate accurate impedance response if we have the same system as actual for calibrating T/S and extended impedance parameters Not much sense imo but it's there.

[kimmosto]

If the chosen port length or diameter was not calculated very accurately, and this only became clear after the final assembly of the speaker with the crossover, I assumed that using the Enclosure Tool I could look and select more correct port sizes. Or disassemble the box and increase its volume.

For example effective volume and End correction are parameters which cannot be calculated with reasonable amount of data so simple box+driver simulators cannot calculate accurate vent length for certain resonance frequency. End correction should be estimated by user. We can use some experimental values, but internal supports, curved vents, flares, vicinity of internal walls etc. makes estimation difficult. Here is commonly used guide for end correction. So tolerance of length is ca. (2.227-0.732)*Dv. Value range in VituxCAD is 0.60-2.40. Of course we could also ask if certain resonance frequency is very important and constant...


Still trying to say that box+driver simulation will not be very high class science no matter how much we add features into software.

[Nil L]

Reet, kimmosto, I read the manual and understood what it was for. Thank you.

[Reet]

I found it worked "well enough" for a pair of 10" passive radiators I had without documentation. I was able to at least get usable enough parameters to put them to use with confidence, but I wasn't that particular about Qa, Ql, etc. for that purpose.

For a bass reflex cabinet however, I think it is easy enough to just measure dimensions and port as a starting point. Again, I don't think exact value of Qa, Ql is that important, use real world measurements of the driver, port, impedance, etc. to determine if the system is underdamped, overdamped, has internal reflection issue, etc.

[kimmosto]

Right. This is how it works. 1) Load Z overlay(s) to graph.

2) Then you can select correct overlay from solver window.

Anyway, I'm quite sure that solver is not able to find solution because it requires almost exact match. That is quite rare in real life.

[Reet]

Where's your impedance overlay to solve with? Read the manual.

https://kimmosaunisto.net/Software/VituixCAD/VituixCAD_help_20.html#Radiator_type

Scroll down a bit, you'll see "Solving parameters of passive and bass reflex radiators".

[Nil L]

What "select button" and solver?

If you click on the field or button to the right of the field marked with a red arrow, you cannot make a selection.

If the chosen port length or diameter was not calculated very accurately, and this only became clear after the final assembly of the speaker with the crossover, I assumed that using the Enclosure Tool I could look and select more correct port sizes. Or disassemble the box and increase its volume.

[kimmosto]

The Enclosure tool has a solver to fit the appearance of the impedance curve to the target. But when I press the file select button, the file system explorer does not appear.

What "select button" and solver? Calculate T/S or Bass reflex or Passive radiator? Everything I have tested works here as designed.

There is a ready-made enclosure with a driver and a port, and there is a measured impedance in this box. T/S driver parameters are included in the database. The shape of the proposed impedance curve is not similar to the measured one.....

What is the problem? Recommended procedure is that after you have actual box, you measure SPL and Z responses, tune if needed, load responses of accepted box+driver to Drivers tab in the main program, design XO with simulator and configure or build XO. That's it. There is no need to override parameters in driver database or try to imitate measured Z response with Enclosure tool and driver database or worry about "normal" parameter differences between (possibly old) datasheet and actual driver samples you have. All that is just extra work after cabinet is accepted and measured for XO simulation.

T/S parameters could have quite large tolerance and changes while burn-in, but that does not cause much or significant effect to box volume. Vent length needs some tuning almost without an exception. Qa, Ql, Qp and Qm of passive are kinda irrelevant. Main target for filling is not to get certain Q. It's to damp possible resonances due to standing waves down to acceptable level. No more.

...many people have this situation.

Why they make this a problem if at least some datasheet version is available and driver is already purchased. Parameter measurement needs driver and some test box or mass(ses). That can be done if T/S parameters are totally unknown or designer suspects that difference to datasheet is radical and wants to verify values of his driver samples before building prototype box (though measurement does not represent global exact values or average).

As already told, Enclosure tool or any other basic box+driver simulator has very narrow purpose. It's not to give accurate impedance curve or filling density, location or Q factors or vent length, location or diameter and so on. Unfortunately it's much less so don't try to put all hopes for it.

[Nil L]

kimmosto,
The Enclosure tool has a solver to fit the appearance of the impedance curve to the target. But when I press the file select button, the file system explorer does not appear. Second. There is a ready-made enclosure with a driver and a port, and there is a measured impedance in this box. T/S driver parameters are included in the database. The shape of the proposed impedance curve is not similar to the measured one. I tried to use the parameters Qa, Ql, Qp to match the appearance of the proposed curve to the measured one. This improved the similarity, but not completely. Then I went through the Table and Ql options on the Align tab. And I repeated the adjustment of the Q parameters. This brought the curves even closer. Then I added 20 liters to the volume of the box of 180 liters. But still the curves were not the same. Question. Can a program do this work on a button solve? If you give her a file with actually measured impedance with amplitude and phase. And using as fitting variables all the parameters that I used and possibly the TS parameters. Because the TS parameters from the manufacturer were created in 2011. Since then, something has changed, improved, and so on. And many people have this situation. After all, there is an actually measured impedance curve. Based on it, you can select the size of the port, the volume of the box (slightly), the frequency of maximum output of the port, and the transient response.

[kimmosto]

New build of 2.0.111.3 has signal limits of 400 Vrms and 80 kW. Switching from P to U signal was not yet fixed in Enclosure.
The same limits in Power dissipation window.

P.S. Enclosure tool is already quite difficult to maintain and update. Too small changes to remember how everything works so number of bugs has increased. Tool is already overshoot for box+driver design though database browser is nice and useful imo. Product quality is done with something else than "volume and vent calculator". Basic simulation with T/S is far from adequate for much more than purchasing decision and preliminary values of those two. More complex radiator concepts are not supported. According feedback users don't seem to see much more than box simulation.