Hello Oliver!
Thank you for the critical revision of my prior post and correcting the severe mistake in it, as it is essential.
Also my prior statement in this post:
"Basicly there is a gain of efficiency above coincidence frequency."
in context with
"The output from some pistonic action is not considered here."
is a little bit sloppy/ misleading too.
Obove coincidence frequency output is gained from bending wave operation.
Below coincidence frequency things get even more complicated. IMO (and as you have noted before) the panel can be seen as an array of multiple dipole sources all having a common orientation but different phase relation. The output from the panel below coincidence is due to pistonic action and not from bending wave operation anymore. This is important because below coincidence phase cancelation effects definitely come into play and the panel size now even more plays a major role regarding LF output. The influence of panel size on modal density is of course still effective.
One problem is that below coincidence the excursion of the exciters' voicecoil has to increase quite fast with decreasing frequency to keep the acoustical output constant. The available exciters are not designed to exhibit large linear excursion. Especially the panels' lowest modes will drive the voicecoil out of the linear excursion range resulting in drastical reduced maximum output respectively high distortion figures clearly audible over the whole range.
Another problem is if we are useing high stiffness materials, the Q-factor of modes (especially the lowest ones) will be very high resulting in a peaky response with very high excursions, so damping becomes meaningfull for FR and reducing excursion.
In any way it should be avoided to excite the lowest modes of the panel because the described effect is most dramatic here (the energy of the modes decreases with rising order), otherwise the maximum possible undistorted output will be comparably low.
Understanding this is IMO one of the key factors when a as small as possible panel size with high output capabilities is the goal.
Please correct me if there is something wrong in this thoughts.
P.S.
I know there are many people in this forums who think this is all just uninteresting technical babbling and don't see the point.
I just like to understand as much as possible of the interactions of the design factors involved and I've learned much (also from "mistakes") since I joined the discussion.
My intention is in helping to define some sort of "practical design corridor".
My point is that I don't have to try out a square wheel when I knew before by envisioning it in my mind, it won't work. My aim is to help saving precious time and money and to accelerate progress in this field, independent of each individual design goal. I'm convinced that there are many possible choices of appropriate panel materials/compositions depending on what someone wants to achieve. It's all about choosing the right compromises in the distinct design. I certainly advocate any attemps in finding meaningful measurement procedures as they can give insight in problems which simply can't be captured by ear. Measurment has always been and will always be an important tool for me just as important as a set of screwdrivers.
Again - IMO something as the "ultimate" panel material for all purposes just can not exist - this would be some sort of closed-minded/ dogmatic point of view and will IMO slowdown progress respectively keep us turning in circles.
with kind regards
Markus
Thank you for the critical revision of my prior post and correcting the severe mistake in it, as it is essential.
Also my prior statement in this post:
"Basicly there is a gain of efficiency above coincidence frequency."
in context with
"The output from some pistonic action is not considered here."
is a little bit sloppy/ misleading too.
Obove coincidence frequency output is gained from bending wave operation.
Below coincidence frequency things get even more complicated. IMO (and as you have noted before) the panel can be seen as an array of multiple dipole sources all having a common orientation but different phase relation. The output from the panel below coincidence is due to pistonic action and not from bending wave operation anymore. This is important because below coincidence phase cancelation effects definitely come into play and the panel size now even more plays a major role regarding LF output. The influence of panel size on modal density is of course still effective.
One problem is that below coincidence the excursion of the exciters' voicecoil has to increase quite fast with decreasing frequency to keep the acoustical output constant. The available exciters are not designed to exhibit large linear excursion. Especially the panels' lowest modes will drive the voicecoil out of the linear excursion range resulting in drastical reduced maximum output respectively high distortion figures clearly audible over the whole range.
Another problem is if we are useing high stiffness materials, the Q-factor of modes (especially the lowest ones) will be very high resulting in a peaky response with very high excursions, so damping becomes meaningfull for FR and reducing excursion.
In any way it should be avoided to excite the lowest modes of the panel because the described effect is most dramatic here (the energy of the modes decreases with rising order), otherwise the maximum possible undistorted output will be comparably low.
Understanding this is IMO one of the key factors when a as small as possible panel size with high output capabilities is the goal.
Please correct me if there is something wrong in this thoughts.
P.S.
I know there are many people in this forums who think this is all just uninteresting technical babbling and don't see the point.
I just like to understand as much as possible of the interactions of the design factors involved and I've learned much (also from "mistakes") since I joined the discussion.
My intention is in helping to define some sort of "practical design corridor".
My point is that I don't have to try out a square wheel when I knew before by envisioning it in my mind, it won't work. My aim is to help saving precious time and money and to accelerate progress in this field, independent of each individual design goal. I'm convinced that there are many possible choices of appropriate panel materials/compositions depending on what someone wants to achieve. It's all about choosing the right compromises in the distinct design. I certainly advocate any attemps in finding meaningful measurement procedures as they can give insight in problems which simply can't be captured by ear. Measurment has always been and will always be an important tool for me just as important as a set of screwdrivers.
Again - IMO something as the "ultimate" panel material for all purposes just can not exist - this would be some sort of closed-minded/ dogmatic point of view and will IMO slowdown progress respectively keep us turning in circles.
with kind regards
Markus
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It's a polyswitch for protection of the transducers.
Like these: Parts-Express.com: Raychem RXE110 1.10A Polyswitch | temperature polyswitch fuses fuse
regards
Markus
Hello Markus,
i think i understand your search for a "design corridor" and
came to similar conclusions so far.
Kind regards
Hello Oliver,
regarding the Aerogel topic discussed some time ago - this is not completely out of sight. There is a hydrophobic granulate material comercially available used for window insulation which is also not too expensive. So it could probably be used in a composite material to contribute to the desired behaviour in a panel.
regards
Markus
regarding the Aerogel topic discussed some time ago - this is not completely out of sight. There is a hydrophobic granulate material comercially available used for window insulation which is also not too expensive. So it could probably be used in a composite material to contribute to the desired behaviour in a panel.
regards
Markus
Hi Markus,
yes why not !
Most likely every good panel material will be a composite
(possibly developed by some audio fanatic) ...
By looking at composites used in the aircraft industry
or in sports equipment, we can see e.g. certain parameters
varying across the size of structures.
The making of musical instruments is full of such
techiques too. Different material properties are
combined to get closer to a desired behaviour.
There are myriads of possibilities.
Concerning your former post:
I just like to add that most of the techiques
used for bass reproduction are resonators.
Examples:
- a dynamic speaker in a closed cabinet is a second order system.
- an open baffled speaker is a second order system often aligned
to have Qts from 0.7 ... 2 to compensate baffle rolloff.
Which not necessarily causes bass response to be "boomy" or low quality ...
- a dynamic speaker in a br cabinet is a fourth order system.
The Qm of the br cabinet itself can easily be > 10 !
In the case of a br cabinet it is the Thiele & Small alignment, which
leads us to controlled and auditively acceptable behaviour.
- Transmissionline cabinets e.g. can have similar behaviour like
DML (-> impedance plot). The resonating structure is a pipe filled
with air, exhibiting resonances according to length, form and kind
of porting at both ends.
Those examples should illustrate, that a resonator with high Q
involved in a system is not a problem in itself necessarily.
It depends on how the whole system is designed and aligned as a
network, including all coupled compliances, mass reactances and
resistances.
Kind regads
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Hello Oliver
I'm aware of the fact that high Q-systems are a very common practice in the loudspeaker business and of most of the examples you mentioned. Often it's a good compromise to keep the systems compact. The other thing is that when room acoustics come into play, IMO many of the side effects of this high Q systems are blurred anyway.
Over the years i had the opportunity to gain much experience regarding sounddesign of large scale high-end sound reinforcement systems (for up to 25000 people) with various different subwoofer approaches and source designs (different stacks, sub arcs, cardioid configurations,...). High Q systems are common here, as high Q has an interrelation to high efficiency. However - high Q-factors in the speaker design is clearly audible to me especially in open air situations and not always in a way that i'm delighted from the performance.
Personly i don't have to like this approach too much and as a designer i have the opportunity to push the compromise away from this. In the end it's a matter of what is required and personal taste.
with kind regards
Markus
I'm aware of the fact that high Q-systems are a very common practice in the loudspeaker business and of most of the examples you mentioned. Often it's a good compromise to keep the systems compact. The other thing is that when room acoustics come into play, IMO many of the side effects of this high Q systems are blurred anyway.
Over the years i had the opportunity to gain much experience regarding sounddesign of large scale high-end sound reinforcement systems (for up to 25000 people) with various different subwoofer approaches and source designs (different stacks, sub arcs, cardioid configurations,...). High Q systems are common here, as high Q has an interrelation to high efficiency. However - high Q-factors in the speaker design is clearly audible to me especially in open air situations and not always in a way that i'm delighted from the performance.
Personly i don't have to like this approach too much and as a designer i have the opportunity to push the compromise away from this. In the end it's a matter of what is required and personal taste.
with kind regards
Markus
Well, this is certainly a new Bit of DIY distraction...I just got 2 pairs of the Parts Express Specials for $10....That, and one 20" x 30" sheet of Black Elmers Foam Board for $5 at the local Stationary Store..Cut in Half....And how I have a Pair of very Different speakers..The first thing you need to do, is pull the Clear Plastic Covers off the Drivers..That, and a goodly amount of properly applied Masking Tape...And..Go Figure..They actually work. Maybe a bit Light on the Bass, but they're only 15" x 20". A nice size to get the Idea of the Potential of these....Pretty much the Sound of a Full Range Single Driver Speaker, but way Cheaper and so many DIY Options..Many more hours of Fussing ahead.
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DML skript
Just some info if anybody is interested in DML simulation:
http://www.randteam.de/_Docs/Aes104 Distributed Mode Loudspeaker simulation model.pdf
The contained skript runs on Akabak.
Download - Akabak
Manual: http://home.comcast.net/~rhcamp0217/acoustics/Manual_Ak21_Main_US.pdf
There is an syntax error in the 3rd line - "**" (Bending stiffnessBs) instead of "B"
Wow! - the censoring algorithm works great here!
regards
Markus
Just some info if anybody is interested in DML simulation:
http://www.randteam.de/_Docs/Aes104 Distributed Mode Loudspeaker simulation model.pdf
The contained skript runs on Akabak.
Download - Akabak
Manual: http://home.comcast.net/~rhcamp0217/acoustics/Manual_Ak21_Main_US.pdf
There is an syntax error in the 3rd line - "**" (Bending stiffnessBs) instead of "B"
Wow! - the censoring algorithm works great here!
regards
Markus
Last edited:
Well I finally got these to Sound Good...First, Round the corners and cover the edges with Black Tape. That takes care of any Buzzing. Then, remove the drivers from the Spider Cases...With the Daytons this is easier than Shucking a Clam....Next, attach them to the Panels with double sided tape. I used some that I use for covering windows with plastic for the winter. This Stuff will stick them on for Keeps. Finally, you need to Crank the Bass up and the Treble down a Click...They will play Bass if it's Cranked. These sound quite nice now from a Sure TA2024 Amp...And Remarkably Loud to Boot...All for a Total of $21....
Hello Markus,
i did run the script, but there was something which makes me wonder:
The element types "DMPanel" , "Exciter" , "DMCoupler"
are neither part of the documentation nor are they integrated into
the forms of the "Def" menu, are they ?
So those DML Elements in Akabak 2.1 seem to be undocumented
builtins ?
Maybe Jörg Panzer had already integrated some DML modeling into
that early Akabak 2.1 version, since he already worked with NXT.
It is a very nice tool to check out some basics concerning panel and
exciter paramers and the effect of both on the behaviour of a DML.
But since i feel, the description of those elements mentioned above
is hidden, it is not a good base for further
understanding and discussion and maybe future refinement and
customization of the model ...
e.g. simulation of panels which have different stiffness dependent on
direction cannot be simulated with that "DEF_DMPanel" function.
I am sure that current software from Panzer/NXT will have evolved.
For those who are interested in DML modeling, this early AkAbak version
may serve as a starting point for pre selecting materials, panel sizes
and so on.
Kind regards
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Hello Oliver!
You are right - there is obviously no documentation of the DML components included in the standard AkAbak Manual - I have not found any further information.
I just posted the link of that specific Manual version as it gives the following information on its' first page:
"NXT has selected AkAbak to be the base for its software front end 'NXT Designer'. The latter is part of the NXT licensee package and incorporates the DML components and tools for panel design. AkAbak is developed in parallel with the NXT Designer, i.e. both packages are compatible. The only differences are the DML components."
The manual gives information about the structure of the script language so that anybody who is interested can at least get an idea how to modify this DML script to his needs. I have no idea if there are more DML functions included in Akabak or not.
There is no doubt that the capabilities of this example script are very limited and some things are not taken into account. It is certainly not the last step in Joerg Panzers modelling approach - actually it is one of his first steps.
It's definitely not my intention to start a discussion on this topic - I just wanted to share what I have found out - that there is a tool you can play with - for free. Maybe it can help to get more insight in this technology as the interactions of the design parameters lead to effects that can not be easely captured in an intuitive way, as one might think. For me it definitely cleared up some things.
with kind regards
Markus
PS. I'd like to share some more information i found - for those who are interested:
http://www.randteam.de/_Docs/Aes105 Radiation Simulation.pdf
http://www.randteam.de/_Docs/Aes106 DML Enclosures.pdf
http://www.randteam.de/_Docs/Aes107 Modal Network Solver.pdf
Some infos about Joerg Panzers projects in the past (from the R&D Team Website):
"AkAbak for DMLs This special implementation of AkAbak is able to simulate the response of multiple exciters on a plate. The plate was assumed to be infinite and some assumption about the radiation were made. This project was done for Mission UK (1996).
PanSys This software simulates the fully coupled system: Lumped elements for the exciter and electronics, modal analysis for the plate, the enclosure and the radiation. PanSys is very powerful in prediction and a particularly useful tool for the design of rectangular plate speakers. The code-base of PanSys is huge and it took us several years to develop (1997).
AFR-Designer simulates the radiation and motor parameter of a fully coupled motor-plate-acoustic loudspeaker driver. The model is based on modal-analysis and axis-symmetry. AFR-Designer makes use of Vacs as output device. This approach dramatically reduced the cost of development because the design concentrates only on the implementation of the mathematics and on the input part. AFR-Designer was designed after specification for Nxt (2003)."
Some info out of the PanSys Manual (this was posted some years ago in the Visaton Forum by somebody who has the NXT System Designer Software):
"The material properties of a panel control the modal distribution of the plate. They are directly linked to the coincidence effects of the acoustic radiation. They describe the material properties of a ready-made panel, which is cut-out in a certain direction (see Panel materials - Width/Height stiffer chapter for details).
The input parameter for the panel material, which PanSys needs are not generic, such as Young's modulus etc. Rather effective parameter of ready made and cut-out panels are used, such as area density and bending rigidity. It has been found that this approach yields more realistic and realisable results than generic parameter. This is especially true for layered panels.
A simulation is only as good as the quality of its input parameters. This is, of course, especially true for the panel parameters. Therefore PanSys comes with an extensive panel database. These parameters are determined and confirmed using a scanning laser interferometer together with a modal identification software tool. As the identification tool uses the same model as implemented in PanSys, this method yields the best fitting parameters.
At very low frequencies the total mass of the plate together with the compliance of the exciter-suspension and supports determine the rigid body resonance frequencies. A panel’s first rigid body mode can be a piston motion as with the conventional loudspeaker. The next possible rigid body mode allows the plate to rotate. If all sides of the plate have Free boundary conditions (FFFF) the first bending mode is close to f0, which is the fundamental engineering parameter of a DML. However, the real first bending mode is shifted because of the coupling to components and to the acoustics. In FFFF mode the on-axis response of the DML is controlled by the first rigid body mode only. The bending modes support the off-axis response. However, in practise the coupling to components masks this ideal effect.
At low and medium frequencies the plate is in pure bending and the vibration pattern is determined also by the plate stiffness in x- and y-direction and some other material constants. The finite size and mechanical conditions at the edges of the plate enforce a field of standing waves, or, so-called bending modes. At higher frequencies shear wave fields add to the bending wave field. The bending wave field is dispersive, whereas the shear wave-field is not. In this frequency range the thick plate theory is applied and gives reasonable good results.
At very high frequencies the plate and its components are vibrating as an elastic volume. At very high frequencies the implemented plate theory stops to be valid.
The simulation model is based on the Kirchhoff-Mindlin plate theory. In principle this theory is valid for flat, thin and homogeneous plates. Any curvature increases dramatically the resonance frequencies of some of the modes due to coupling between bending and membrane effects.
The plate must be thin enough to ensure that the front and rear surfaces of the panel move in parallel. As a rule of thumb, the thickness should be smaller then a sixth of the bending wave-length.
Homogeneous, means that section parameters are constant along any direction. In the transverse (z) direction this constraint is not satisfied by usual sandwich constructions. However, since there is assumed to be no wave field in the z-direction, the different material parameters of each layer are lumped into so called section parameters, such as the effective bending rigidity of the panel.
The panel can be stiffer in one direction than the other, which is taken into account by the two components of the bending rigidity, D1 and D2. If D1 = D2 then the plate is said to be isotropic, otherwise an-isotropic. In the context of the program, D1 and D2 are assumed to be aligned with the edges of a rectangular cut-out. Panel parameters are therefore always annotated by the degree under which the panel was cut-out (for example: 0/90 or +/-45 degree).
In a plate, the bending wave field cannot be completely separated into independent fields in x and y direction. This is because there is coupling resulting from shear-mechanics and lateral/direct strain. Coupling is controlled by the in-plane-shear (Shr) and the Poisson ratio parameters, which are also dependent on the way the panel is cut-out.
Although the panel is assumed to be infinitely thin with respect to transverse waves and with respect to diffraction, there are some important effects related to the thickness, which modify the bending wave field. The thicker the plate, and the higher the frequency, the more influential the effects of finite transverse shear rigidity and the inertia of rotation of a section. The controlling parameters are called “thick plate parameter” (see thickness, t, and shear modulus, Gz).
In addition to the bending and shear wave-fields, there is a local elasticity at any driving point. The effect of elasticity can be observed at high frequencies where the local stiffness goes in resonance with the mass of the voice-coil and the mass-type reactance of the aperture effect.
At very high frequencies (usually around 10kHz) the driving point mechanics become very complex. With the help of the in-build plate model extensions it is possible to go beyond the limits implied by the usual plate theory and to display all effects involved. However, in the upper frequency band the uncertainty of the result-curves increases with frequency."
You are right - there is obviously no documentation of the DML components included in the standard AkAbak Manual - I have not found any further information.
I just posted the link of that specific Manual version as it gives the following information on its' first page:
"NXT has selected AkAbak to be the base for its software front end 'NXT Designer'. The latter is part of the NXT licensee package and incorporates the DML components and tools for panel design. AkAbak is developed in parallel with the NXT Designer, i.e. both packages are compatible. The only differences are the DML components."
The manual gives information about the structure of the script language so that anybody who is interested can at least get an idea how to modify this DML script to his needs. I have no idea if there are more DML functions included in Akabak or not.
There is no doubt that the capabilities of this example script are very limited and some things are not taken into account. It is certainly not the last step in Joerg Panzers modelling approach - actually it is one of his first steps.
It's definitely not my intention to start a discussion on this topic - I just wanted to share what I have found out - that there is a tool you can play with - for free. Maybe it can help to get more insight in this technology as the interactions of the design parameters lead to effects that can not be easely captured in an intuitive way, as one might think. For me it definitely cleared up some things.
with kind regards
Markus
PS. I'd like to share some more information i found - for those who are interested:
http://www.randteam.de/_Docs/Aes105 Radiation Simulation.pdf
http://www.randteam.de/_Docs/Aes106 DML Enclosures.pdf
http://www.randteam.de/_Docs/Aes107 Modal Network Solver.pdf
Some infos about Joerg Panzers projects in the past (from the R&D Team Website):
"AkAbak for DMLs This special implementation of AkAbak is able to simulate the response of multiple exciters on a plate. The plate was assumed to be infinite and some assumption about the radiation were made. This project was done for Mission UK (1996).
PanSys This software simulates the fully coupled system: Lumped elements for the exciter and electronics, modal analysis for the plate, the enclosure and the radiation. PanSys is very powerful in prediction and a particularly useful tool for the design of rectangular plate speakers. The code-base of PanSys is huge and it took us several years to develop (1997).
AFR-Designer simulates the radiation and motor parameter of a fully coupled motor-plate-acoustic loudspeaker driver. The model is based on modal-analysis and axis-symmetry. AFR-Designer makes use of Vacs as output device. This approach dramatically reduced the cost of development because the design concentrates only on the implementation of the mathematics and on the input part. AFR-Designer was designed after specification for Nxt (2003)."
Some info out of the PanSys Manual (this was posted some years ago in the Visaton Forum by somebody who has the NXT System Designer Software):
"The material properties of a panel control the modal distribution of the plate. They are directly linked to the coincidence effects of the acoustic radiation. They describe the material properties of a ready-made panel, which is cut-out in a certain direction (see Panel materials - Width/Height stiffer chapter for details).
The input parameter for the panel material, which PanSys needs are not generic, such as Young's modulus etc. Rather effective parameter of ready made and cut-out panels are used, such as area density and bending rigidity. It has been found that this approach yields more realistic and realisable results than generic parameter. This is especially true for layered panels.
A simulation is only as good as the quality of its input parameters. This is, of course, especially true for the panel parameters. Therefore PanSys comes with an extensive panel database. These parameters are determined and confirmed using a scanning laser interferometer together with a modal identification software tool. As the identification tool uses the same model as implemented in PanSys, this method yields the best fitting parameters.
At very low frequencies the total mass of the plate together with the compliance of the exciter-suspension and supports determine the rigid body resonance frequencies. A panel’s first rigid body mode can be a piston motion as with the conventional loudspeaker. The next possible rigid body mode allows the plate to rotate. If all sides of the plate have Free boundary conditions (FFFF) the first bending mode is close to f0, which is the fundamental engineering parameter of a DML. However, the real first bending mode is shifted because of the coupling to components and to the acoustics. In FFFF mode the on-axis response of the DML is controlled by the first rigid body mode only. The bending modes support the off-axis response. However, in practise the coupling to components masks this ideal effect.
At low and medium frequencies the plate is in pure bending and the vibration pattern is determined also by the plate stiffness in x- and y-direction and some other material constants. The finite size and mechanical conditions at the edges of the plate enforce a field of standing waves, or, so-called bending modes. At higher frequencies shear wave fields add to the bending wave field. The bending wave field is dispersive, whereas the shear wave-field is not. In this frequency range the thick plate theory is applied and gives reasonable good results.
At very high frequencies the plate and its components are vibrating as an elastic volume. At very high frequencies the implemented plate theory stops to be valid.
The simulation model is based on the Kirchhoff-Mindlin plate theory. In principle this theory is valid for flat, thin and homogeneous plates. Any curvature increases dramatically the resonance frequencies of some of the modes due to coupling between bending and membrane effects.
The plate must be thin enough to ensure that the front and rear surfaces of the panel move in parallel. As a rule of thumb, the thickness should be smaller then a sixth of the bending wave-length.
Homogeneous, means that section parameters are constant along any direction. In the transverse (z) direction this constraint is not satisfied by usual sandwich constructions. However, since there is assumed to be no wave field in the z-direction, the different material parameters of each layer are lumped into so called section parameters, such as the effective bending rigidity of the panel.
The panel can be stiffer in one direction than the other, which is taken into account by the two components of the bending rigidity, D1 and D2. If D1 = D2 then the plate is said to be isotropic, otherwise an-isotropic. In the context of the program, D1 and D2 are assumed to be aligned with the edges of a rectangular cut-out. Panel parameters are therefore always annotated by the degree under which the panel was cut-out (for example: 0/90 or +/-45 degree).
In a plate, the bending wave field cannot be completely separated into independent fields in x and y direction. This is because there is coupling resulting from shear-mechanics and lateral/direct strain. Coupling is controlled by the in-plane-shear (Shr) and the Poisson ratio parameters, which are also dependent on the way the panel is cut-out.
Although the panel is assumed to be infinitely thin with respect to transverse waves and with respect to diffraction, there are some important effects related to the thickness, which modify the bending wave field. The thicker the plate, and the higher the frequency, the more influential the effects of finite transverse shear rigidity and the inertia of rotation of a section. The controlling parameters are called “thick plate parameter” (see thickness, t, and shear modulus, Gz).
In addition to the bending and shear wave-fields, there is a local elasticity at any driving point. The effect of elasticity can be observed at high frequencies where the local stiffness goes in resonance with the mass of the voice-coil and the mass-type reactance of the aperture effect.
At very high frequencies (usually around 10kHz) the driving point mechanics become very complex. With the help of the in-build plate model extensions it is possible to go beyond the limits implied by the usual plate theory and to display all effects involved. However, in the upper frequency band the uncertainty of the result-curves increases with frequency."
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Btw - there is the parameter AbsorbCoeff missing for the Radiating component in the example script.
It's possible to simulate a closed back DML with it (I guess) when it is set to 1. Default setting is 0 for radiation from both sides.
Syntax:
|Radiating component
DMPanel 'DM1' Def='DM1' AbsorbCoeff=0
x=0 y=0 z=0 HAngle=0 VAngle=0
regards
Markus
It's possible to simulate a closed back DML with it (I guess) when it is set to 1. Default setting is 0 for radiation from both sides.
Syntax:
|Radiating component
DMPanel 'DM1' Def='DM1' AbsorbCoeff=0
x=0 y=0 z=0 HAngle=0 VAngle=0
regards
Markus
Is it possible that 'AbsorbCoeff' models the
inherent mechanical loss of the panel ?
I do not know, maybe your interpretation is right.
Kind regards
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