VituixCAD v2

[tktran]

Merger tool can also use “Diffraction response (5-30m)”
If you omit it and select “No baffle loss” it will output 2pi

[Quza]

The default SPL trace in the Enclosure tool is 2pi, 4pi can be shown when a diffraction response is added. I'm wondering what the result of the Merger tool is when combining NF response from cone and port with diffraction response, also 4pi? If so, can the 2pi response be calculated?

[Quza]

You can just send them an email. Dr. Sean Olive answered my questions on head and torso simulators within a few minutes and was highlighting the cons of each option, even though we never spoke before. Erin Hardjson is also open to suggestions on his reviews.
And fwiw I agree and am curious on their answers.

[tktran]

Some suggestions on this topic: https://kimmosaunisto.net/Misc/speak...w_feedback.pdf
I may not have enough courage to publish or send that as PM on ASR or EAC. Wall of Toole's and Olive's science bubble is so strong on those medias.
Any thoughts?

Yes I agree with many of your points.

I came to similar thoughts about usefulness of globe charts and normalized polar maps and harmonic distortion.

In general, much of the science in Toole's book is about 20 years ago and may be represent the research at the time on the speakers of the time.

In my field, by the time something's published in a book it's already outdated. Not completely wrong but has been further refined.

So for audio, following Toole and Olive may be easier for the consumer to understand. And perhaps that is the point of it- to help consumers make a purchasing decision. But it leaves a lot to be desired/understood in the current era. Active, DSP driven speakers, small (consumer) and large (PA) that might not rate highly on the Preference scale, as seen by Spinorama.org.. perhaps that's why they've changed to 'tonality'

With science we are willing to refine/change our thinking.

Changing process is more difficult eg. ASR methodology.

[kimmosto]

Can't see it.

1234

[tktran]

Re: 61 Celestion drivers added to online database.

Can't see it. What am I doing wrong?

[kimmosto]

all this is kinda part of long term plan to turn twisted or narrow scope of objective evaluation, and encourage to select acoustical concepts which have possibilities to produce both shallow and linear enough directivity slopes.

Some suggestions on this topic: https://kimmosaunisto.net/Misc/speak...w_feedback.pdf
I may not have enough courage to publish or send that as PM on ASR or EAC. Wall of Toole's and Olive's science bubble is so strong on those medias.
Any thoughts?

[kimmosto]

2.0.118.4 (2024-10-25)

Enclosure

• Align Closed gives warning "Increase Qa to normal range 2-120 to avoid too small volume." if Qa < 1.5.
• Minimum volume with Align Closed decreased from 0.1 to minimum value of Vb text box (0.0001).
• Align Closed calculation of 2.0.109.2 (2023-10-05) restored to get Qtc detected from impedance response closer to selected target.

61 Celestion drivers added to online database. Thanks to Simon R/Celestion for entering data.

[kimmosto]

I understand a need for accuracy and consistency among multiple systems that are claiming to produce the same charts. To understand the context of this change of calculation, are we talking about something significant, that would impact design decisions, or just some "hair splitting" of small errors / differences.

Small differences do not probably have any effect to project which is already designed mechanically and acoustically and designer is already tuning XO.

In practice, slope of directivity responses is as important as smoothness - especially for casual listening. Correct slope results enable one consistent feedback mechanism to explain and learn why certain speakers sound bad and some others good in the same environment and locations.
This looks weak point in Toole's and Olive's studies because listeners were probably nailed to the spot. Narrow band deviations and smoothness got high significance and slopes none. This probably reflects also to results and conclusions by reviewers and preference rating enthusiasts who rely (too) much on narrow scoped studies. Boomy or/and muffled speakers might be praised due to biased interpretation of spinorama.

So all this is kinda part of long term plan to turn twisted or narrow scope of objective evaluation, and encourage to select acoustical concepts which have possibilities to produce both shallow and linear enough directivity slopes.

[Reet]

Great, another unapproved post, for no reason this time. Love this forum...

[Reet]

I understand a need for accuracy and consistency among multiple systems that are claiming to produce the same charts. To understand the context of this change of calculation, are we talking about something significant, that would impact design decisions, or just some "hair splitting" of small errors / differences.

[kimmosto]

2.0.118.3 (2024-10-18)

Main

• CTA-2034-A button in Options does not change SPL/Directivity span, Aspect ratio of exported images and Angle step if 5 or 10 deg. Other angle steps are changed to 10 deg.
• Default width of exported graphs changed to 640 px.

Sorry that I continue to undo old modifications requested by some users. Graphical recommendations such as 50 dB span of spinorama and aspect ratio of 25 dB/dec in SPL charts presumably support publishing of CTA-2034 and other SPL graphs, but they don't support everyday design work. That is priority #1 so they won't be defaults anymore.
Klippel owners calculate CEA 2034 with 10 deg angle steps, but for example I usually run Outline ET with 5 deg steps and use the same resolution for calculations. So CTA-2034-A button in Options won't manipulate settings which are fully acceptable for designing and probably give more accurate result also in spinorama.

[kimmosto]

Modifications around spinorama are not far from parody anymore. Available written references have been 'Sound reproduction' by Toole and CTA-2034-A final. Both are quite simplified and indefinite so at least Klippel, Pierre of spinorama.org and I have made own inquiries, interpretations and comparisons.

One of the first and biggest problems was ER Rear calculation due to wrong interpretation what "Hor 180 deg, +/-90 deg" means. It's whole rear sector in hor plane, but some of us interpreted it wrong. For example, mistake in Klippel affected years to ER Horizontal, ER Total, PIR and ERDI results published on ASR and everywhere else. Most of the reviews still have wrong results visible. The latest reviews look okay, but I have not verified very carefully.

Another PITA is power response / sound power calculation. CTA decided to provide their own weighting factors which deviate from textbook values and calculation. Table for 10 deg angle steps is okay but 5 deg is totally screwed up. Anyway, CTA specifies:
"The sound power is the weighted rms average of all 70 measurements, with individual measurements weighted according to the portion of the spherical surface that they represent. Calculation of the sound power curve begins with a conversion from SPL to pressure, a scalar magnitude. The individual measures of sound pressure are then weighted according to the values shown in Appendix C and an energy average (rms) is calculated using the weighted values. The final average is converted to SPL."
BUT Klippel, spinorama.org and VituixCAD with CTA-2034-A power weights checked do not use that order (as I read it). All three calculate: pressure squared -> weighting -> summing -> square root -> to SPL. VituixCAD does not force to use CTA's factors and formulas so I'm the worst skeptic allowing traditional textbook calculation (by unchecking CTA-2034-A power weights). Difference is not huge though.

The latest disappointment was to notice that VituixCAD is the only app. without squaring LW, ER and SP before weighting for PIR calculation. Squaring is not specified in CTA. PIR is not "official" curve in spinorama so maybe it's okay to skip. Toole has written that spec. to his book. I found it after comparison to Klippel and spinorama.org so there was small error for quite many years.

[kimmosto]

2.0.118.2 (2024-10-17)

Main

• Predicted in-room response calculated as PIR=sqrt(0.12*LW^2+0.44*ER^2+0.44*SP^2).
  Squaring is specified in Sound Reproduction by Floyd E. Toole. Not in CTA-2034-A final.

Preference rating

• Default slope targets of PIR modified for updated PIR calculation.

[kimmosto]

2.0.118.1 (2024-10-16)

Enclosure

• 'Paste T/S parameters' command improved (to support format on Celestion's web site, Celestion drivers are coming to online database).
• Clicking Manufacturer in header row sorts driver table by Manufacturer and Model (this was actually done to 2.0.118.0).

[kimmosto]

2.0.118.0 (2024-10-15)

Preference rating

• Values in slope column shown in dB/oct and dB/dec as tooltip.
• Default slope targets by 'Full space' button modified.
• Default slope targets by 'Half space' button modified.

Enclosure

• Added driver database filtering criteria for passive radiators. Criteria appear when PR is checked.
• Enclosure project name removed (as too temporary) from window title.
• Driver database file is shown in window title with full pathname. Helps to track location of current database especially if user has several databases in local or cloud drive.

SPL Trace

• Maximum frequency limit increased to 10 MHz.

[kimmosto]

2.0.117.1 (2024-10-12)

Main

• 'CTA-2034-A power weights' setting in Options saved to project file.

Impulse response, Convert IR to FR

• Peak value of WAV files with integer data type normalized to maximum positive value - 2: 16-bit PCM 32766, 24-bit PCM 8388606, 32-bit PCM 2147483646, 64-bit PCM 9223372036854775806.

Preference rating

• Adjustment range of slope targets widened to 2.

Calculator

• Fixed reading of 'Linear input mag.' checkbox of B response. For example Protection cap A z B has not been working since 2.0.111.0 (2024-01-05).

[kimmosto]

Impulse response paragraph in online user manual modified 2024-07-28.

"Electrical signals (Buffer outputs and Driver inputs) exported at once have common scaling factor to maintain gain differences.
Acoustical signals (Driver SPL and Total SPL) exported at once have common scaling factor to maintain sensitivity differences.

Level normalization with WAV files:

• Peak value of exported 16-bit PCM wav files is normalized to 32760.
• Peak value of exported 24-bit PCM wav files is normalized to 8388607.
• Peak value of exported 64-bit IEEE wav files is normalized to 1.0.
• 32-bit IEEE wav files transfer original signal values (without normalization) to maintain correct SPL and gain values when IR is converted back to frequency domain with FFT.
  Note! Values > 1.0 will cause clipping and some unexpected results with applications expecting scaling within +/-1.0 of standard 32-bit IEEE audio wav. In that case you should select some other output format: 16-bit PCM, 24-bit PCM or 64-bit IEEE, or adjust generator's voltage to reduce absolute peak level below 1.0."

[kimmosto]

I think more polar map palettes won't be available. Klippel palette was requested by one user who wanted to compare to Klippel and avoid too wide green + cyan area which is common/unavoidable with computer screens and linear color circle. Gray palette could be okay for b&w (paper) publications.
Drawing of contour lines was originally done as graphical operation using linear color circle only. That logic was not changed for Klippel and gray palettes because it would require full reprogramming. So with other than linear color circle palette, every pixel should be transformed back to linear color circle to get correct result.

[Quza]

I'm a little late to the color palette party, but Colorcet perceptually accurate palettes may be helpful. (https://colorcet.holoviz.org)
Also, some colorblind options, like matplotlibs RdYlBu may be a nice addition for some users. (https://matplotlib.org/stable/users/...colormaps.html)
I'm using RdYlBu_r for our datasheets and think it looks great. (https://images.static-thomann.de/pic..._en_online.pdf)

[kimmosto]

2.0.117.0 (2024-07-22)

Enclosure

• Added Import button to 'Add new driver' window. Supports VituixCAD .vxd, WinISD .wdr, Basta! .bastaelement, Hornresp .txt, SpeakerSim .sdrv and Speakerbench .json T/S parameter files.
• Importing can be done also by Drag & Drop to the window.
• Paste button disabled while window is in 'Edit parameters' mode to avoid resetting all parameters.

[kimmosto]

Equivalent circuit of an inductor is compatible with LTspice. Still quite simple but gives some tools to simulate losses.

[kimmosto]

2.0.116.0 (2024-07-20)

Main

• Added parallel resistance Rpar and parallel capacitance Cpar parameters to passive Inductor component. Rpar is included in calculation if Value < 1 MOhms. Power dissipation of Rpar is ignored. Cpar is included in calculation if Value > 100 pF.
• Optimize Off (Ctrl+E) command in context menu of XO schematic resets Opt attribute of all parameters.

Merger

• Save button renamed to Merge.

[kimmosto]

2.0.115.2 (2024-07-12)

Merger

• Added 'Visible frequency range only' checkbox.

[kimmosto]

2.0.115.1 (2024-07-12)

Convert IR to FR

• Allowed any sample rate within 44100...768000 Hz.

[witwald]

Thank you for that. It's much appreciated.

[witwald]

I'm at a loss to understand why someone would want to use HFD as a measurement tool, it's quite bad.

Please note that I am NOT using HFD as a measurement tool. I inadvertently did one rapid frequency sweep without any data capture, so that's the total of my "experience" using HFD as a measurement tool. It sure startled me!

Some software purpose built for measuring like REW or ARTA would be a better solution,...

Not to forget some other measurement systems, such as CLIO, IMP/M, Audiosuite, MLSSA, B&K Pulse, etc.

...where active filter design can be completed by VituixCAD, and filter blocks copied over to HFD simply to push them to the DSP.

In a roundabout way, that is something that I am trying to do, as VituixCAD has much better overall simulation capabilities (of course) than HFD. Funnily enough, I have encountered some major issues using HFD, as it routinely produces "Access violation errors" when I try to read in the text files containing impulse response data. This error seems to corrupt things within HFD's memory space, sometimes in a way that the simulated curves in HFD are modified. The biggest problem that I have encountered is that when I load a tweeter impulse response file into HFD, the frequency response is shifted down in frequency for some unknown reason.

That's where VituixCAD comes to my rescue, allowing me to perform the simulations that I need to be able to work with.

[kimmosto]

My wild guess is that the files are response data for some project originally designed for Hypex DSP, and witwald wants to return it to simulator for possible tuning or conversion for some other DSP gear. The first option wouldn't add much value because VituixCAD is not able to show or do much more than HFD so it must be conversion...🤔

[Reet]

I'm at a loss to understand why someone would want to use HFD as a measurement tool, it's quite bad. Some software purpose built for measuring like REW or ARTA would be a better solution, where active filter design can be completed by VituixCAD, and filter blocks copied over to HFD simply to push them to the DSP.

[kimmosto]

...it would greatly promote interoperability.

VituixCAD does not officially support Hypex due to proprietary biquad coefficient calculation of HFD i.e. simulated responses won't be exactly the same as produced by Hypex DSP. I would expect some co-operation and interoperability promotion also from Hypex.
Anyway, any sample rate between 44100...768000 Hz will be allowed in the next revision, though VituixCAD's main tasks with IR files are:
a) Read raw measurement data, typical sample rates divisible by 22050 or 24000 Hz.
b) Produce/export processed frequency response files or IR files with any - also Hypex's odd sample rates.

[witwald]

I have been trying to load impulse response files written in the MLSSA format into the "Convert IR to FR" tool. When I use a file whose time step between samples is 0.010666666666667 milliseconds, corresponding to a Hypex DSP-compatible sampling rate of 93750Hz, I get an error message: "Samplerate 93750 Hz is not supported".

The first few lines of my file are as shown below:

0
0.010666666666667
65536
-2.082129E+02
3.694307E+03
1.558122E+04
1.405175E+04
-6.690195E+02
:

Is this a bug, or is there a way that I can use my impulse response file?

[witwald]

I am trying to use VituixCAD's "Convert IR to FR" capability. I have an impulse response text file containing a sequential list of 65536 sampled floating-point values, where the sampling rate used was 93750Hz. This sampling rate is used by the Hypex DSP-enabled plate amplifiers. A snippet of the data at the beginning and end of the file is shown below:

-208.21291788177
3694.30732619709
15581.2232067774
14051.7458438195
-669.019517933816
-4681.39384516699
-1202.73093352386
   :
   :
1.65295396072906E-05
-2.75267613005781E-05
2.66568804363487E-06
2.76369109997177E-05
0

When I try to read in the file, I use the "Impulse response files (*.pir,*.mls,*.crp,*.txt,*.wav)" option:



After selecting the file and clicking Open to load it, I get the following error message:



Then I try to select the sample rate of 93750Hz, which is available from the drop-down list:



When I click OK, I then get the following error message:



Would it be possible to support the 93750Hz sample rate, as well as impulse response files that don't have a header? These are in the format used by the Hypex Filter Design program, and if VituixCAD was able to support that format it would greatly promote interoperability.

[witwald]

Thank you for the clarification. With 48 points per octave, starting at 5Hz, that makes the last point in the 5Hz–40000Hz range set to be equal to 5*2^(12+46/48) = 39793.948 Hz, which matches the exported data. I now much better understand how those frequency settings work.

[kimmosto]

All of the above seems to be at odds with having the ability to set the frequency limits using the Options dialog box.

User manual says:
"Frequency axis
Internal frequency range is fixed 5...39794 Hz with density of 48 points/octave, but you can define initial visible scale with minimum 5...5000 Hz and maximum 40...40000 Hz."
So graph scale settings in Options don't limit anything. Just set initial values user can adjust temporarily if needed.

The reason is that limited frequency range is one the most poisonous features in input and output data. Range should be as wide as possible at both ends that VCAD and other applications should not have to extrapolate. Extrapolation is possible if target system has wider range, but it requires conversion to time domain, resampling to sample rate of max freq. x 2 e.g. with some interpolation for HF and assumptions or window function for LF and finally conversion back to freq. domain.
It's not rare that the same data is used for different projects e.g. analog XO and 48k DSP XO. All input data is better to be 5-40k to be compatible with any project.

Of course there is one exception: projects with DSP XO sample rate < 80 kHz . Data is displayed and exported up to Nyquist.

[witwald]

I've been doing some simulations, and I've noticed that I can't use the cursor to read off a point at 20000Hz, even though the frequency limits are set to 5Hz and 20000Hz. Is this by design? See the screen snapshot below for an example.

Interestingly, when I use the cursor to investigate the value at 5Hz, I can do so. Also, if I change the high-frequency limit to <=10000Hz, then I can get the final value.

Also, I have noted that, when results are exported to a text file, the data always covers the range from 5Hz to 39793.9Hz, irrespective of the frequency axis limits that have been set. An example of this behaviour is shown in the following snippet of exported data shown below.

Freq[Hz] dBSPL Phase[Deg]
5.00000 -54.079 -7.161
5.07273 -54.081 -7.264
5.14651 -54.084 -7.369
5.22137 -54.087 -7.474
:
:
38106.8 -71.176 -81.846
38661.1 -71.299 -81.956
39223.4 -71.422 -82.064
39793.9 -71.546 -82.171

All of the above seems to be at odds with having the ability to set the frequency limits using the Options dialog box.

[kimmosto]

2.0.115.0 (2024-07-07)
Main

* Added 'Gray palette' option for directivity Polar map. Activated from context menu of directivity chart -> Contour lines -> Gray palette.
* Default palette' command in context menu restores standard colour circle palette.

Preference rating

* Removed radio buttons for Olive's equations 9 and 10.
* Added Sound pressure slope target SL_SP.
* Added 'Show target' checkbox. Selected target is shown in Power & DI chart.
* Slope targets displayed also in dB/dec (in addition to dB/oct).
* Added 'Full space' button. Initializes slope targets for conventional (boxed) design.
* Added 'Half space' button. Initializes slope targets for flush-mounted design.
* Added 'Constant DI' button. Initializes slope targets for constant directivity design.
* SM and NBD are calculated as slope-independent with all parameters.

[kimmosto]

I am a bit confused why the "with sub" check box has turned into a "ignore LF" button.

I thought button would work but it did not because preference max. of 10.0 requires that LFX x it's weight and LFQ x it's weight should be constants > 0 in the equation to produce certain effect/gain to different variables. So 'with sub' is now restored as it was.

Another change is that Olive buttons are removed. Olive's factors can be set by pressing Ctrl or Shift while clicking 'Full space' but that could stay hidden/secret feature.

Default initial factors may require some tuning to prefer minimum NBD_PIR over maximum SM_PIR i.e. slightly curved PIR is allowed but without narrow resonances visible to many directions. Both can be good at the same time, but real life produces some errors and differences.

[Reet]

I like the idea of displaying the slope target in the main window, it makes it easier to visualize and set the target appropriately. I am a bit confused why the "with sub" check box has turned into a "ignore LF" button. I like Ignore LF as a better description, but why the change to a button? In any case, I still primarily rely on the axial and in-room response optimization over the preference rating tool. Once I find a good result using axial and in-room response at 50/50 weight, if I try to re-optimize using preference rating, any change in the result has been very minor.

[kimmosto]

Sketching PR window...
Slope target is possible to show in Power & DI. Cursor in SL_PIR field or SL_PIR checked alone shows PIR target etc.
Three initial weighting factors for Equation group; default, Olive 9 and Olive 10. Olive presets uncheck slope targets. Factors for Full space with default weights are visible below.
Three initial slope targets; Full space (conventional box), Half space (flush-mounted) and Constant directivity.
Ignore LF resets LFX and LFQ which are >0 with Olive preset.

This may look complex, but should be quite easy to use. Normally just click Full space, select Slope target e.g. check SL_LW and run Optimizer with 'Preference rating'.
Any opinions/comments?

[kimmosto]

Polar map with gray palette is done too, but not much value imo so it could stay hidden reserve.

P.S. Resolution of contour lines is lower due to 8-bits only.

[kimmosto]

I'm cleaning Olive's equations and adding sound power slope target (SL_SP) to PR window because this is design tool. No more comparison to spinorama.org, ASR etc.

Olive's weighting factors would be easy to copy to the fields, but calculated rating is much higher because SM and NBD are insensitive to slope with this custom equation.

[kimmosto]

2.0.114.2 (2024-06-30)

Main

• Unit of group delay traces in GD & Phase chart changed from milliseconds (ms) to cycles (cyc) when 'Normalized' is checked in context menu.

[Reet]

I like it. Limiting the normalization to max 10kHz also allows one to extend the frequency range to 40kHz to show ultrasonic tweeter breakup without negatively impacting the overall chart scaling.

[kimmosto]

2.0.114.1 (2024-06-28)

Main

• Peak level within 20-10000 Hz is normalized to red (dark red with Klippel palette) in directivity Polar map also while 'Normalized' is unchecked.

Enclosure

• Fixed calculation with multiple passive radiators. Bug since version 0.1.4.13 (2016-06-20).

[Reet]

Yes, I would prefer that. As it is, the example you show above will appear very orange/yellow, with a red peak at 15kHz and with no ability to change it.


Another idea would be to provide an option for user adjustment of a single frequency for palette normalization could work well enough for most people, complete speaker or individual driver evaluation. For a complete speaker, something like 1kHz could be used, then user adjusts to perhaps 5kHz for a tweeter only chart, or 200Hz for a woofer chart. The software could provide automatic peak detection to set the normalization frequency for most use cases, with user ability to adjust to a non-peak frequency if desired.