VituixCAD v2

[Reet]

For the intended purpose of diffraction simulation, which would be to apply to nearfield response of a woofer, I would probably just take the size of the facet directly horizontal to the centre of the woofer and apply that as a roundover and call it good, so red trace if I understand your descriptions properly.

I know you have some completed speakers with these big facets, why don't you compare with your own real-world measurements? Which one of these responses when applied to the nearfield response and merged, has the best alignment with the final speaker measured response?

[DaveFred]

At the risk of splitting hairs, I am wondering how to best model enclosure diffraction when the cabinet has beveled facets.

Here is the cabinet drawing, 350mm tall, 180mm wide, driver 190mm from bottom, driver SD 54cm^2,



And here are some diffraction simulations,

Orange - 180mm cabinet width with square edges ignoring the bevel
Red - 180mm cabinet width, treating the bevel as a roundover based on where the bevel lands in the middle of the woofer
Purple - 180mm cabinet width, treating the bevel as a roundover based on where the bevel is at the top of the woofer
Green - 150mm cabinet, treating the cabinet width as being the bevel in the middle of the woofer.

I realize that for the purpose of baffle step, these are all within 1/2 dB and not going to make a world of difference, I was just wondering which simulation would you consider most correct?

My poorly educated guess would be "Red".



Thank you,

David.

[kimmosto]

2.0.131.1 (2025-11-02)

Diffraction

• Movement of effective acoustical center to off-axis angles is simulated by subtracting group delay at 5-7 Hz from all off-axis responses, including diffracting waves. This eliminates e.g. shifting of high-pass frequency of open baffle on frequency axis as the radiator size changes.

[kimmosto]

Ok, thanks! Let's try wider publication.

2.0.131.0 (2025-10-29)

• Target framework changed from .NET Framework 4.5.2 to 4.8. That's the last supporting Windows 7 sp1.

[Reet]

As far as I can tell, everything is working normally via Wine, though with slower performance and ugly aliased charts. There were some messages spit out to the terminal, I'm not sure how detrimental they are. Here's an example:

01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01d8:fixme:thread:NtQueryInformationThread ThreadIsIoPending info class not supported yet
019c:fixme:olepicture:OLEPictureImpl_QueryInterface () : asking for unsupported interface {c3fcc19e-a970-11d2-8b5a-00a0c9b7c9c4}
019c:fixme:olepicture:OLEPictureImpl_QueryInterface () : asking for unsupported interface {b196b283-bab4-101a-b69c-00aa00341d07}
019c:fixme:olepicture:OLEPictureImpl_QueryInterface () : asking for unsupported interface {af86e2e0-b12d-4c6a-9c5a-d7aa65101e90}
019c:fixme:olepicture:OLEPictureImpl_QueryInterface () : asking for unsupported interface {ecc8691b-c1db-4dc0-855e-65f6c551af49}
019c:fixme:olepicture:OLEPictureImpl_QueryInterface () : asking for unsupported interface {94ea2b94-e9cc-49e0-c0ff-ee64ca8f5b90}
019c:fixme:olepicture:OLEPictureImpl_QueryInterface () : asking for unsupported interface {00000003-0000-0000-c000-000000000046}
019c:fixme:olepicture:OLEPictureImpl_QueryInterface () : asking for unsupported interface {00000144-0000-0000-c000-000000000046}
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF960, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF960, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF960, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
01a4:fixme:ole:thread_context_callback_ContextCallback 00007F2821451798, 00006FFFF9F52B80, 00007FFFFF4FF850, {d7174f82-36b8-4aa8-800a-e963ab2dfab9}, 2, 0000000000000000
019c:fixme:oleacc:find_class_data unhandled window class: L"WindowsForms10.COMBOBOX.app.0.141b42a_r7_ad1"
019c:fixme:oleacc:find_class_data unhandled window class: L"WindowsForms10.COMBOBOX.app.0.141b42a_r7_ad1"
019c:fixme:oleacc:find_class_data unhandled window class: L"ComboLBox"
019c:fixme:oleacc:find_class_data unhandled window class: L"ComboLBox"
019c:fixme:oleacc:find_class_data unhandled window class: L"WindowsForms10.COMBOBOX.app.0.141b42a_r7_ad1"
019c:fixme:oleacc:find_class_data unhandled window class: L"WindowsForms10.COMBOBOX.app.0.141b42a_r7_ad1"
019c:fixme:oleacc:find_class_data unhandled window class: L"ComboLBox"
019c:fixme:oleacc:find_class_data unhandled window class: L"ComboLBox"

[draki]

W11 Pro 25H2/ 64: works OK, can't notice any problem so far...

[Reet]

I primarily have been using VituixCAD in a Windows 10 VM. I pushed many buttons and found no issues installing the updated version above.

Within Linux, I have avoided VituixCAD running under Wine for two reasons - performance, and right click context menu often disappears immediately after clicking, making the UI unusable. Give me a little time and I will test the new version.

[kimmosto]

I'm going to change .NET Framework requirement from 4.5.2 to 4.8 which is the last one Windows 7 sp1 supports. Would you care to test it on real Win7, Win10, Win11, some Virtual machine on macOS or linux, and possibly with Wine 10.12 or later.
I have tested on Win 11 Pro 25H2 and Win 7 sp1 on VMware Workstation Player 16 (on Win 11 Enterprise 23H2).
No functional changes compared to 2.0.130.1.
---Link removed---

[kimmosto]

Few examples about time windowed far measurements without any post-processing could give some answers about usability of directivity data also with short time gate. Absolute accuracy is different thing, but we can make quite safe assumptions especially with simple conventional concepts without surprises in directivity:

6.5" boxed woofer, 8" passive radiator in the back. There is some extra directivity at LF due to time window, reflections, possible noise and DC offset. That can be reduced with 'Force to gradient' feature.



2x15" woofers in I-frame dipole baffle, hor plane. DI at LF may be a bit less than in theory, but generally directivity is captured down to 20 Hz. Very much smoothed but again, we know that it is smooth with quite plain I-baffle.



Designer can use Diffraction tool to simulate directivity to 0-180 deg, and Calculator to include that directivity to any on-axis response, and finally merge two sets of far field responses with Merger: LF part contains simulated directivity and HF part measured directivity. Merging could be e.g. at 150 Hz with blending of 3-4 octaves. This is also "wrong", but so is everything (including NFS) except real far field measurements at 2-3 m in anechoic.

[mv8]

Thanks for the explanation, Kimmo

[kimmosto]

...in his opinion, the technique of combining near-field measurements and off-axis far-field measurements (as is done in VituixCAD) is wrong.

Of course it is wrong, and all credits belong to something else 😁 But seriously, most of the messages by Bohdan seem to include some wrong assumptions how Merger works - or at least what is possible with Diffraction+Calculator+Merger. Very short answer to default usage is that directivity of merged LF data is adopted from far field HF responses. So it does not merge plain near field multiplied by on-axis diffaction to far field with some blending. Of course not, because that would produce radical error. Time window causes smoothness to directivity data at LF. That is one of inaccuracies in default usage. Other inaccuracies are near field measurement itself (cone behavior), simulated diffraction and magnitude+phase error at LF due to time window and selected window function.

[mv8]

Of course though I prefer e-mail and delayed answering after few months.

Okay, I wanted to send you a link to a conversation I had with Bohdan about merging measurements. I am not competent enough to discuss this topic at the appropriate level, but here are a few of Bohdan's answers in which he explains why, in his opinion, the technique of combining near-field measurements and off-axis far-field measurements (as is done in VituixCAD) is wrong.

I remembered this conversation, and that's why I asked my first question about the implementation of Matched Filter in VituixCAD.

https://groups.io/g/Soundeasy/topic/odp_soundeasy_using_the/102932391

[kimmosto]

May I send you a private message?

Of course though I prefer e-mail and delayed answering after few months.

[mv8]

kimmosto Thank you for your reply and explanation. May I send you a private message?

[kimmosto]

If you have the time and the will to read a bit of the SoundEasy manual, it might be worth adding this feature to the Convert IR to FR tool?

I had time to read. Procedure contains multiple steps, parameter adjustments both numerically and graphically, and some evaluations and possible undos for each measurement. Parameters probably variate depending on off-axis angle. This does not fit very well to preferred measurement procedure where each driver is measured semi/full automatically 0-180 or 0-360 with steps of 10 or 5 degrees, and LF+MF drivers at near field. Bohdan also says:
"In addition, before you start using this tool, please be aware, that close-mike measurement technique, coupled with diffraction analysis, will yield equally good, if not better results, simply because the reflections are attenuated by the virtue of the measurement technique...
Therefore, once you become confident with Cepstral Deconvolution, you may try to use it for all quick, first-cut activities, and move to close-mike measurements for the final results."

I kinda disagree with Bohdan because near field and diffraction simulation are not difficult and complex compared to cepstrum method. The only possible problem is accuracy of simplified diffraction model. SE probably has better diffraction simulation compared to VCAD's rapid and easy approach.

By the way, someone else asked averaging of impulse responses measured from different distances. That would require probably 10x more measurements for each driver, automatic and manual (sub-sample) fine tuning of timing, magnitude scaling with distance etc. Also this is possible for on-axis only, but way too extreme for off-axis with dual plane or balloon measurement.

[mv8]

Sure, I understand.
Matched Filter and Cepstral Deconvolution operations are performed on impulse measurements, so I think the easiest way would be to include such a function in the Convert IR to FR tool.
Most importantly, these functions do not require any additional measurements, so when measuring far field, we have data for possible further processing.

I also see no reason why these options could not be implemented in REW.

[Reet]

Frankly I gave up on SE on version 26 after feeling like I was paying to be a beta tester, and struggling to converse with the developer on simple concepts like whether baffle step should be treated as an energy gain or an energy loss. My comments above were simply thinking about what a practical implementation in VituixCAD would look like.

Perhaps the cepstral editor question could be posed to John Mulcahy of REW as well.

[mv8]

I don't see anyway around the merge process in VituixCAD, regardless of the method to fill in the low frequency portion of the windowed response, you still need a mechanism to apply it to the complete "high frequency portion" measurement set in bulk.

There's nothing preventing you from loading an un-windowed measurement as an overlay, use active filter components to design the equivalent matching filter and use that as the low frequency portion in the merge tool. I'm not sure it's saving many steps though, it may actually be a faster process just to measure near field and simulate diffraction.

Cepstral editing was one of the more unique features of SoundEasy when I used it. I thought it was a very cool feature with a very clunky UI, and at the time I was using SE it was limited to only a maximum of 48kHz measurement sample rate.

Have you tried measuring spinorama on a turntable using SoundEasy with the Matched Filter function?

[Reet]

I don't see anyway around the merge process in VituixCAD, regardless of the method to fill in the low frequency portion of the windowed response, you still need a mechanism to apply it to the complete "high frequency portion" measurement set in bulk.

There's nothing preventing you from loading an un-windowed measurement as an overlay, use active filter components to design the equivalent matching filter and use that as the low frequency portion in the merge tool. I'm not sure it's saving many steps though, it may actually be a faster process just to measure near field and simulate diffraction.

Cepstral editing was one of the more unique features of SoundEasy when I used it. I thought it was a very cool feature with a very clunky UI, and at the time I was using SE it was limited to only a maximum of 48kHz measurement sample rate.

[mv8]

kimmosto Kimmo, I sometimes use SoundEasy for measurements, which, in my opinion, has an interesting function of “cleaning” measurements from the influence of the room. It is solved using the Cepstral Deconvolution or Matching Filter function. If you have the time and the will to read a bit of the SoundEasy manual, it might be worth adding this feature to the Convert IR to FR tool?

When used correctly, this feature allows you to avoid combining near-field and far-field measurements.

https://www.bodziosoftware.com.au/ SoundEasy V30 Reference Manual: Chapter 16.2, from page 16 to the end.

[kimmosto]

2.0.130.1 (2025-09-28)

Enclosure

• Fixed compliance calculation with isobaric configuration. Bug since 2.0.15.1 (2019-04-28).
• 'W to Ohm' text box updated also with isobaric configuration.

[Reet]

1m measurement distance is still not completely far field as 3m typical listening distance, so 1m diffraction response allows for small improvement of accuracy. For a similar reason, near field diffraction is completed using 10-30m distance, not 1m. It helps to avoid speakers sounding too thin due to inadequate BSC from inaccurate response data.

[bnilsson]

Thanks.
That brings up another related question regarding Merger.
I have never been able to understand, or missed it completely in the instructions, why does Merger need two diffraction correction files, one near (e.g. 1000mm) and one far (e.g. 5000mm)?

[bnilsson]

Thank you, that fixed the problem.

[kimmosto]

I have a cylindrical enclosure standing vertical with the driver mounted on top, pointing upwards.
Consequently the orientation is 90 degrees vertically in reference to the listener.
I have selected a listening/microphone distance of 1000mm, which will be in the same plane as the driver mount, sideways to the cylinder axis.
In the layout graph describing the baffle, driver and microphone, where should the microphone be located to conform to this geometry?
Should it be in the middle of the driver, or at the bottom, outside the baffle?

Baffle step is not visible to 90 deg off-axis with this kind of very simple diffraction simulation. Response includes directivity of an ideal piston, but nothing more. If you are creating diffraction response for Merger tool, you can create circular baffle (36 corners, height=width), driver and mic in the center point, and export response to 90 deg off-axis. Hor or Ver does not matter. Axis distance should be what Merger needs; one export to 30000 mm and another to distance where actual far field measurements are captured.

[kimmosto]

If I connect a first order 1000Hz 6dB HS and a first order 1000Hz 6dB LS in series I expect them to give a straight 6dB gain, no frequency dependence.

There are two different specifications for corner frequency of shelving filters. I would call them "analog" compatible and "RBJ digital" compatible. Corner frequency is kinda "-3 dB point" with "analog", and middle gain (in dB) with "RBJ digital". For example Sigma Studio and miniDSP use "RBJ digital", and most of European brands use "analog" specification. The same problem exists with 2nd order shelf and Bessel HP/LP filters. This is really annoying imo too.

So you need to select suitable DSP system in Options window to be compatible with your gear or app. Generic should be compatible with Sigma Studio. Another gear using Sigma project is Platin SM 48k, but it's for 48k sample only. I use that DSP amp quite often.

[bnilsson]

I have a question about low and high shelf filters in VituixCad.
If I connect a first order 1000Hz 6dB HS and a first order 1000Hz 6dB LS in series I expect them to give a straight 6dB gain, no frequency dependence.
This is how such a filter combination behaves in REW, and also in SigmaStudio DSP design software.
However, in VituixCad I get a bump of +2dB at 1000Hz over the +6dB flat. Why?
This behaviour make a design tuned in VituixCad not transferrable to e.g. SigmaStudio, which is annoying.

[bnilsson]

Dear all,

I have a question about the Diffraction Tool.
I have a cylindrical enclosure standing vertical with the driver mounted on top, pointing upwards.
Consequently the orientation is 90 degrees vertically in reference to the listener.
I have selected a listening/microphone distance of 1000mm, which will be in the same plane as the driver mount, sideways to the cylinder axis.
In the layout graph describing the baffle, driver and microphone, where should the microphone be located to conform to this geometry?
Should it be in the middle of the driver, or at the bottom, outside the baffle?

BN

[tktran]

Kimmo,

You are correct that the 8260A was the first coaxial that was made into a Genelec. It was Ilpo's idea but the design was such they could only make 6 a day.

After this they decided to use 2 oval woofers, above and below the centrally mounted large "baffle" 8351A - Genelec.com but to do this, they needed to hire a transducer designer. (Genelec could not design/simulate driver's prior to this) The smaller Ones came out later. 8341A, 8331A, together marketted as The Ones: gen_theones_brochure_210x279_12pager_lowres_0.pdf

The larger 8361A and updated 8351B came later.

But putting subwoofer against a hard surface might be OK for subwoofer egs. <120Hz, but woofers that cross up as high as 320Hz to meet the coaxial.

Well the designers must be listening with their eyes. Or people are measuring incorrectly and not paying attention to Time Domain.

[tktran]

I can. They are good for beginner level. Only problem is he is using single channel measurement technique and Xsim.

As a previous course user, I reach out to him and said, you should update your course for dual channel and using VituixCAD2, and he vehemently agreed. When he has some time...

[tktran]

I asked this question in 2019...

https://www.audiosciencereview.com/forum/index.php?threads/should-we-i-get-into-speaker-testing-measurement.7904/post-191634

Today it's just a tool for marketing using some old science from the 20th century, from Floyd Toole's book to KEF and Genelec products that generate a clean looking spinorama.

They can't even measure a Soundbar, nor make sense of what makes a good one from a bad one. And whenever serious comment or a question is raised, there's a heap of hand waving going on. eg. my recent exchanges with Lars or Jack

[Reet]

I would say yes, but I also know that writing a book is a lot of work, and I already have a full time job. Also, in the effort of keeping with the times, a video series would be much more popular with "internet education" in mind. Again, a lot of work to do it well and cover many topics in depth.

For sale, Marius from Audio judgement sells some courses here:

https://audiojudgement.com/courses.html

I can't vouch for how good they are or the accuracy of information contained within, however.

[kimmosto]

Where should one go to find a consolidated gospel of truth, laid out in a concise progression path like a textbook for a complete understanding of acoustics as it related to loudspeaker design?

I agree that available textbooks and internet sites are not very inclusive, and data has been scattered to many places. The best books for beginners are DIY speaker books such as Dickason's (in English) and Tuomela's (in Finnish). CTA-2034-A standard fills few holes in those because it's just 2+ decades old. For example ER, PIR and SP. Lack of goals/recommendations and best practices is a big problem. Usefulness of old generic basic/filtered studies (by Toole), deep theories (by Beranek&Mellow) and publications in AES Library is quite light for designing imo.

AI can search and summarize, but it could lie smoothly or just quote forum discussions so everything must be questioned and verified.
Maybe we should write something better

[Reet]

You may be surprised how many are oblivious to much of these "general basic things known for four decades", especially in DIY Audio where most are trying to educate themselves via the internet. Most are struggling with basic concepts and interpretation of SP and PIR, let alone group delay, step response, etc. Where should one go to find a consolidated gospel of truth, laid out in a concise progression path like a textbook for a complete understanding of acoustics as it related to loudspeaker design?

[kimmosto]

Relevant: https://www.aes.org/tmpFiles/elib/20250731/17839.pdf

I'm developing an allergy to Toole's documents and Sound Reproduction book. They seem more useless every day. Close to nothing for speaker designing and different concepts. Just general basic things known for four decades, added with indefinite statements that can also be interpreted as false claims.
For example timing / phase distortion in 3rd edition, chapter 4.6, pages 77-78: "...humans are very sensitive to variations in amplitude vs. frequency, and very insensitive to phase shifts. In other words, we do not "hear" waveforms per se, but we are very sensitive to their spectral content."
Everything is left to interpretation. He himself interprets it as not having to worry about the excess group delay - of any length, so the phase response is either systematically omitted from the documents or downplayed so much that gullible reader becomes convinced of its complete insignificance. However, the audibility is easily detectable even with headphones with phase distortion equivalent to some actual speakers+subwoofer. Tested again a few minutes ago.

[Reet]

Relevant: https://www.aes.org/tmpFiles/elib/20250731/17839.pdf

[augerpro]

I don't remember what authoritative source I heard that from, as you said some form of it has bounced around the forums for a long time. I'm almost sure it was in Sound Reproduction, but I just don't remember anymore.

[kimmosto]

augerpro Your Waveguides page contains this image:

I tried to find the reference for "-6dB 100-10khz drop on axis vs power response found by Harman to be most preferred in listening tests". In the beginning also ChatGPT answered that ca. -1 dB/octave slope is recommended, but in the end it didn't find any references, papers or books and page numbers. Some posts in diy audio forums, and general statements by Toole et al. without exact values or ranges. Do you remember where you got that phrase from?

This question is related to slope targets in VituixCAD. My plan is to clarify the ranges and logic between different slope targets in Preference rating window. So far I've been using statistics of measured speakers and concepts, and referred book "Tee itse hifikaiuttimia" by P. Tuomela's including this text: "A suitable power response reduction is typically 5-6 dB between 200 Hz and 12 kHz. An exact guideline value cannot be given, as it is also affected by the free-field response and the directivity of the speaker". Those sentences leave out acoustics, listening setup, "bad" 80s recordings etc. so more tolerance may be needed.

Current calculation formulas for target ranges can be found here:

Slope target limits as C# code for...

[kimmosto]

2.0.128.0 (2025-07-29)

Diffraction

• Added very simple emulation for directivity of a waveguide. Does not emulate change in efficiency and on-axis SPL. 'Waveguide mimic' group includes Enable checkbox, Cutoff in Hz and Slope in dB/oct text boxes. A circle in green dashed line is drawn outside the driver(s) when emulation is enabled.
• Axis Hor and Axis Ver can be non-zero at the same also with rectangular driver.

Poetry in the user manual:

Waveguide mimic
This is a simple emulation for directivity of a waveguide. Emulation does not include change in efficiency and on-axis SPL. There is no response boost (and anyhing for impedance) so result cannot be used for designing equalization. Actual waveguide/horn simulation would be much more complicate requiring all dimensions, shape of cross-section(s) and driver parameters.
Emulation is activated with Enable checkbox in 'Waveguide mimic' group. A circle in green dashed line is drawn outside the driver(s) when emulation has been enabled.
Frequency where directivity starts is adjusted with Cutoff textbox in Hz.
Change in directivity as a function of frequency is adjusted with Slope text box in dB/oct. Value to be adjusted is slope of off-axis response to 90 degrees in half space (infinite baffle without directivity due to baffle edges). Range is from -0.1 to -6.0 dB/oct.
Root response for emulated off-axis responses is transfer function of the 1st order low-pass filter. That is manipulated with Slope parameter and direction (angle) from the driver to virtual mic/listening point. Waveguide is assumed to be circular. Directivity calculation of the driver (as an ideal piston) is limited between -50 and +50 degrees i.e. opening angle of the throat is assumed to be ca. 100 degrees.

[augerpro]

Looks great to me!

[kimmosto]

Test app simplified to circular due to some mathematical challenges

[kimmosto]

Mockup with simple directivity. That could use ca. transfer function of 1st order low-pass at cut-off manipulated by slopes and off-axis angles (up to 90 deg).

[kimmosto]

I wonder if you could create a driver type for the baffle diffraction simulator that would mimic a waveguide? Define a cutoff frequency and directivity slope above that slope.

Yes I could. The simplest solution would be tiny throat (without directivity of the driver) and constant circular directivity slope down to cut-off frequency, but I'm afraid directivity of the driver to small off-axis angles, closer to CD with steeper cut-off, and elliptical, square or rectangular wave guide with different parameters for horizontal and vertical planes will be asked quite soon. This may open Pandora's box

[augerpro]

I wonder if you could create a driver type for the baffle diffraction simulator that would mimic a waveguide? Define a cutoff frequency and directivity slope above that. Currently when prototyping where I intend to use a waveguide on the tweeter, I just use a driver diameter (say, 4") that is similar to the actual waveguide response around the intended crossover frequency so I can understand how the response will combine with the midrange response. But above some frequency the driver response drops off quickly offaxis, which the actual waveguided tweeter does not do.

[kimmosto]

2.0.127.3 (2025-07-16)

Enclosure

• Added 'Equivalent Peak Dissipation Resistance' (EPDR) trace to impedance chart.