Calvin.
If you want to know how a driver stops then you should use a signal that stops as well. A Step does never ever stop at all !!
Regards
Charles
If you want to know how a driver stops then you should use a signal that stops as well. A Step does never ever stop at all !!
Regards
Charles
I have no idea how these factors impact upon sound quality, but here is my take on some of the issues raised in this thread.
There is the physical issue of energy flow. What we are trying to do is take the energy from an aperiodic electrical power source and convert it into acoustic energy.
The problem, is that to do this with most conventional drivers, most of the effort is expended in moving a large mass (the driver motor & diaphragm.
This has the other "side effect" of adding phase shift, and for transient signals, characteristic risetime and overshoot - even ringing, depending on the mass, spring force and damping parameters of the mechanical assembly. I would have thought most drivers are sufficiently damped to avoid significant overshoot and ringing. Does this not just leave us with phase shifts and a certain frequency response?
Cheers,
Ed
There is the physical issue of energy flow. What we are trying to do is take the energy from an aperiodic electrical power source and convert it into acoustic energy.
The problem, is that to do this with most conventional drivers, most of the effort is expended in moving a large mass (the driver motor & diaphragm.
This has the other "side effect" of adding phase shift, and for transient signals, characteristic risetime and overshoot - even ringing, depending on the mass, spring force and damping parameters of the mechanical assembly. I would have thought most drivers are sufficiently damped to avoid significant overshoot and ringing. Does this not just leave us with phase shifts and a certain frequency response?
Cheers,
Ed
454Casull said:
You are moving a 4-space object in 4 space and we are seeing a 3-space projection of it in our space. As it is a force field i see no reason why a baffle in 3-space couldn't bisect the 4-space object.
dave
I was thinking more above 500Hz as a wide BW unit, however (big however), seeing as you mention it, there is no real reason why one could not design or drive, say, a bass horn with a suitable compression unit, or several compression units. IMO, you'd be better off with a couple of high quality direct radiating HE 15in woofers, but YMMV as ever of course.
As for material resonance, I tend to take the view that ringing like a bell is not automatically a problem in & of itself. It depends where it occurs in the FR, and if it's well above the operating BW, who cares? Same goes for the resonant BW of cabinet panels for that matter. An active filter / XO would be preferable of course, given the issues many metal cones & passive XOs have -look at the Seas Thor kit & the XO mods many people have been compelled to make. But then, they're preferable anyway IMO.
A famous quote from Colin Chapman (adapted from Ed Heinemann) I tend to keep in mind though for most things: 'simplify and add lightness.'
As for material resonance, I tend to take the view that ringing like a bell is not automatically a problem in & of itself. It depends where it occurs in the FR, and if it's well above the operating BW, who cares? Same goes for the resonant BW of cabinet panels for that matter. An active filter / XO would be preferable of course, given the issues many metal cones & passive XOs have -look at the Seas Thor kit & the XO mods many people have been compelled to make. But then, they're preferable anyway IMO.
A famous quote from Colin Chapman (adapted from Ed Heinemann) I tend to keep in mind though for most things: 'simplify and add lightness.'
454Casull said:
Before that can be answered we'll actually have to figure out how to build things in 4-space (if even possible)
dave
At that point my math ability waves the white flag. I just don't have that kind of mind.
PS -Dave, are you OK? Haven't seen you round much recently.
PS -Dave, are you OK? Haven't seen you round much recently.
Scottmoose said:
I have a flu, and my eyeballs feel like they have gravel in them from the recent pollen rains (my truck is no longer white, it is yellow)
Thanx for asking.
dave
rjbond3rd said:
The local honey is good, but the problem with the pollen isn't allergies... it is the pollen being blown directly into my eyes -- so very fine gravel.
dave
Hi,
I don´t think that we have different opinions about the working principle of the Manger. I´ve read the papers and patents. I Just say that in praxis it doesn´t work so much after theory as it is implied by the marketing departement, ie. website 😎
Below app 500Hz it doesn´t work as bendingwave transducer but as a pistonic dynamic driver. Its just above this frequency range that it begins to work in a bending wave fashion (this is not so much different to any other dynamic driver of the 8" class. The ´break-up-frequency is a bit lower, because of the very soft membrane, but that´s all) . According to the theory and the explanation on the website one should see in the pics that with increasing frequency more and more parts of the membrane should remain still and ever smaller parts of the membrane should be in movement. In contrsat to this You can see that the complete membrane is in motion even at 10kHz (I don´t know if the colouration of the pics just shows different phase angles of the motion or if the colour contains information about the excursion level of this mambrane segment too). Anyway, it clearly shows that the whole membrane is moving, which is in contrast to the claimed behaviour. It´s the same behaviour a stiff membrane could show with frequencies small compared to the length of the circumference.
The difference is, that the break-up modes are better dampened with the soft membrane and don´t execute high Q-values like a much stiffer cone.
If You look at the dispersion of the Manger it is very similar to any other 8" driver, with the lobing of the dispersion beginning at ~2kHz and increasing strongly and in a very similar way a soft-membraned bass (e.g PP-membranes) would do. One can see distinctive comb-filter-effects ~8kHz and above. So again nothing seriously different to a normal dynamic driver.
CSD plots.....again nothing really differnet ...nothing outstanding
Distortion values.....rather highish and similar to other large membraned drivers ´misused´ for tweeter purposes.
So apart from the step response I don´t see any advantage for the Manger using classical measurement methods.
It would be interesting to see if other measurement parameters like ETC-curves et al show any remarkable differences. I like the idea of reducing the number count of energy storage mechanisms and think that there must show some measurable effect that correlates with the claims and which improves the driver´s behaviour.
jauu
Calvin
I don´t think that we have different opinions about the working principle of the Manger. I´ve read the papers and patents. I Just say that in praxis it doesn´t work so much after theory as it is implied by the marketing departement, ie. website 😎
Below app 500Hz it doesn´t work as bendingwave transducer but as a pistonic dynamic driver. Its just above this frequency range that it begins to work in a bending wave fashion (this is not so much different to any other dynamic driver of the 8" class. The ´break-up-frequency is a bit lower, because of the very soft membrane, but that´s all) . According to the theory and the explanation on the website one should see in the pics that with increasing frequency more and more parts of the membrane should remain still and ever smaller parts of the membrane should be in movement. In contrsat to this You can see that the complete membrane is in motion even at 10kHz (I don´t know if the colouration of the pics just shows different phase angles of the motion or if the colour contains information about the excursion level of this mambrane segment too). Anyway, it clearly shows that the whole membrane is moving, which is in contrast to the claimed behaviour. It´s the same behaviour a stiff membrane could show with frequencies small compared to the length of the circumference.
The difference is, that the break-up modes are better dampened with the soft membrane and don´t execute high Q-values like a much stiffer cone.
If You look at the dispersion of the Manger it is very similar to any other 8" driver, with the lobing of the dispersion beginning at ~2kHz and increasing strongly and in a very similar way a soft-membraned bass (e.g PP-membranes) would do. One can see distinctive comb-filter-effects ~8kHz and above. So again nothing seriously different to a normal dynamic driver.
CSD plots.....again nothing really differnet ...nothing outstanding
Distortion values.....rather highish and similar to other large membraned drivers ´misused´ for tweeter purposes.
So apart from the step response I don´t see any advantage for the Manger using classical measurement methods.
It would be interesting to see if other measurement parameters like ETC-curves et al show any remarkable differences. I like the idea of reducing the number count of energy storage mechanisms and think that there must show some measurable effect that correlates with the claims and which improves the driver´s behaviour.
jauu
Calvin
And the thing getting worse with the theory. Please point any book in which it author explains in depth how traveling wave radiates sound below coincidence (subsonic plane waves). Manger simulates infinite plate so truncated wave-field in the far-field does not apply.
Anti Pollen masks
Hi Planet 10
Just a quick idea on eye protection that might help you.
I have seen local farm workers and grain transport drivers wear what looks like ScubaPro silicone diving masks to protect their eyes.
You can get the masks in all sizes and some dive shops offer a heated mold service to custom shape a mask to the exact contours of your face.
Overall not a cool look (!) but it should stop the pollen / dust getting into your eyes.
To all, I will catch up soon on the outstanding replies, family and work hectic right now!
All the best
Derek.
Hi Planet 10
Just a quick idea on eye protection that might help you.
I have seen local farm workers and grain transport drivers wear what looks like ScubaPro silicone diving masks to protect their eyes.
You can get the masks in all sizes and some dive shops offer a heated mold service to custom shape a mask to the exact contours of your face.
Overall not a cool look (!) but it should stop the pollen / dust getting into your eyes.
To all, I will catch up soon on the outstanding replies, family and work hectic right now!
All the best
Derek.
A little OT but for those interested in the aforementioned new Beyma coaxial - I just found a preliminary data sheet:
http://www.supersonic.se/links/6CX200Nd_tec.pdf
An analog crossover for this driver could be quite a brainteaser.
Regards
Charles
http://www.supersonic.se/links/6CX200Nd_tec.pdf
An analog crossover for this driver could be quite a brainteaser.
Regards
Charles
Overkill website
I took my website offline about 10 months ago (you haven't visited in a long time...???!!!) when I sold the business.
I had some good IP and two very good design concepts for on wall speakers utilising NXT's little BMR drivers with the rigid (paper) cones.
I am still waiting to see if I will actually ever earn any royalties....!
On the Beyma coax... a simple passive will be tough but if any one can do it its you!
With a 10dB sensitivity difference between the drivers, I think one of your phase accurate active analog designs is the way to go.
Then there is no need for some big hot "Thermal Compression in a tube" resistors to destroy the efficiency of the compression driver.
Could you also build in a "little wiggle" of EQ maybe?
For my application I only need the driver to go down to 80Hz at -3dB. Small sealed box (special shape & materials) so no ABR's, slots, ports or resonance.
All the best
Derek.
I took my website offline about 10 months ago (you haven't visited in a long time...???!!!) when I sold the business.
I had some good IP and two very good design concepts for on wall speakers utilising NXT's little BMR drivers with the rigid (paper) cones.
I am still waiting to see if I will actually ever earn any royalties....!
On the Beyma coax... a simple passive will be tough but if any one can do it its you!
With a 10dB sensitivity difference between the drivers, I think one of your phase accurate active analog designs is the way to go.
Then there is no need for some big hot "Thermal Compression in a tube" resistors to destroy the efficiency of the compression driver.
Could you also build in a "little wiggle" of EQ maybe?
For my application I only need the driver to go down to 80Hz at -3dB. Small sealed box (special shape & materials) so no ABR's, slots, ports or resonance.
All the best
Derek.
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