PETTaLS Flat Panel Speaker Simulation Software

The sample I have is transparent. It was a glass coming with a frame. Ikea frames mention also polystyrene for their glass.
It is sold here as a substitute to real glass in different thickness.
I heard about PST/HIPS as high impact polystyrene. I will try to see if it is referenced like that in the DIY store.
Christian
Christian...I think the material you describe is most likely acrylic
Eucy
 
inspection of the impedance curves suggests a significantly higher Q for the plywood than for the PMMA.
I am surprised by that, but it is the crux of the issue in modelling the various panel materials in use.

I went by the 5 value used for MDF and bumped it up a bit, but you're suggesting a huge leap...

And then we take the raw material and apply coatings....🤷‍♂️

We need a full blown lab 😵‍💫😵‍💫
Eucy
 
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I just got a macbook so that I can compile the code for iOS - should be coming within a few days!
Oh wow thanks Dave, no pressure as I'm sure I can borrow a PC or it may work on my windows workaround I just haven't tried yet. Looking forward to having a play with it and trying different placement options non physically.
Have you had any contact with Ben Zenker of Xcite? I'm not sure if he views the DML full range forum or partakes under another name. I'm sure your program would be of interest to him as I remember from one of his videos he manually tried many many placements to model panel behaviour.
 
Do you know what is this transparent variant of PS used as protective glass for frames
In my experience..acrylic Christian
acrylic

Picture frame glass and acrylic both come in clear finishes. This choice is common for most artwork and photography, especially for pieces with vibrant colors. It offers full, window-like clarity, allowing all the detail to pop right out of the frame.
 
In my experience..acrylic Christian
acrylic
I also thought so, until I read what Wiki says:
"Polystyrene (PS) /ˌpɒliˈstaɪriːn/ is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene.[5] Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to air and water vapor and has a relatively low melting point.[6] Polystyrene is one of the most widely used plastics, with the scale of its production being several million tonnes per year.[7] Polystyrene is naturally transparent, but can be colored with colorants."

I have never seen transparent polystyrene myself. This is all new to me.
 
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Oh wow thanks Dave, no pressure as I'm sure I can borrow a PC or it may work on my windows workaround I just haven't tried yet. Looking forward to having a play with it and trying different placement options non physically.
Have you had any contact with Ben Zenker of Xcite? I'm not sure if he views the DML full range forum or partakes under another name. I'm sure your program would be of interest to him as I remember from one of his videos he manually tried many many placements to model panel behaviour.
The iOS version is now available on github!

Getting in touch with Ben is on my list. My students and I are still trying to figure out the best way to model the DA exciters we have, so I was hoping to get through all of that first.
 
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My students and I are still trying to figure out the best way to model the DA exciters we have, so I was hoping to get through all of that first.
Hello Dave,
I would be interested to have a better understanding of how PETTaLS models the exciters. As there are already 2 exciters in the current version, I thought it was a closed topic. Seems not?
Christian
 
I would be interested to have a better understanding of how PETTaLS models the exciters. As there are already 2 exciters in the current version, I thought it was a closed topic. Seems not?
Some exciters, like the two models that are in my software already, are easy to model. Some, like the DAEX32Q-8, behave a little differently. I'm trying to come up with a comprehensive model that works for everything... it might be overkill, though.

The model is still pretty close to Ch.5 from my thesis. It's now probably closer to what's outlined in This paper, but it was pretty hard to make heads or tails of what was going on in those old NXT papers (because they wanted to keep it proprietary, I'm sure).
 
The iOS version is now available on github!

Getting in touch with Ben is on my list. My students and I are still trying to figure out the best way to model the DA exciters we have, so I was hoping to get through all of that first.
Thanks Dave! I didn't expect you to do it so fast or at all!

I was more meaning Ben would be interested in using PETTals rather than asking for more exciters to be loaded.

I downloaded the iOS version but it says it can't be opened on my Mac as it says it's damaged and should be moved to the bin, should it work on MacOs or is it for iOS on an IPad? Or is there other software needed to host it? Sorry I couldn't find info on the host program on the Github but I remember there was something needed to run it on Windows?

Thanks again
 
Dave,
I want to emphasize how much I appreciate this post. I think it really helps me put some things in a new perspective.
In flat panel speaker "lore" there is a lot of idealization of the "pebble in pond" wave, as in these snips from the Goebel site:

View attachment 1437596
View attachment 1437598

I've always thought that the Goebel site was at least a little "hyperbolized" (like most audio lit), but now I'm more convinced that there is really no great advantage of the PIP pattern over the simply "localized" pattern. Both excite a sufficient number of modes to produce a very wide and even radiation pattern. So I'm a a lot less inclined to target the "PIP" response over a wide frequency range, if the "localized" response provides similar directivity without the need for extreme damping measures.
Does this make sense, or am I missing something?
Eric
Eric -

I've been thinking more about the high-frequency schemes, and I think there's more to be said that's difficult to quantify...

One of the perceptually interesting things about sound coming from a panel is that the source really is "distributed" over space, as opposed to a traditional loudspeaker where the size of the driver is normally meant to be much smaller than the wavelength of the reproduced frequency, so that the sound appears to emanate from a single point. The picture below is one example of how modal patterns produce a really distributed acoustic source, the "localized" pattern is somewhat in between, and the PIP pattern is a very localized source. The bottom row of graphs is a nearfield SPL map with the speaker at the bottom center.

1742755014919.png


The PIP pattern is probably almost always above coincidence, though, which muddies the results a bit.
 
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Thanks Dave! I didn't expect you to do it so fast or at all!

I was more meaning Ben would be interested in using PETTals rather than asking for more exciters to be loaded.

I downloaded the iOS version but it says it can't be opened on my Mac as it says it's damaged and should be moved to the bin, should it work on MacOs or is it for iOS on an IPad? Or is there other software needed to host it? Sorry I couldn't find info on the host program on the Github but I remember there was something needed to run it on Windows?

Thanks again
Yeah, I meant macOS. I renamed the file. I'm mostly an iPhone user so I just had iOS in the back of my mind. Oops!

This is apparently just a problem with macOS not liking third party apps. This worked for me:

https://discussions.apple.com/thread/253714860?sortBy=rank
 
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I was more meaning Ben would be interested in using PETTals rather than asking for more exciters to be loaded.
JoskaNZ,
I'm sure Ben would be interested to try Pettals, but he has his own version of it, I would say. He describes in section 3 the attached paper. It's not something you or I could run, however without pretty expensive software and even more extensive knowledge of how to use it! Dave has put it in a form that is inexpensive (free!) and accessible. It's a great thing.
Eric


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