Cone breakup and similar effect WILL reflect in distortion.
Just look at any aluminum cone and see how the curve basically is "copied" in the distortion.
3.1.4
https://www.klippel.de/fileadmin/_m...linearities–Causes_Parameters_Symptoms_01.pdf
-of course a lot of what's seen in the more obvious bell-mode "aluminum cone" results is a by-product of amplitude gain from that bell-mode (raising non-linear distortion that "trails" with increasing-order harmonics "left" and "right" of that peak in amplitude). "Notch-it-out" and there is typically a substantial reduction broad-band with respect to those "trailing" higher order harmonics because the problem at that bell-mode is now suppressed in spl relative to the average.
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Yes, I am extremely familiar with Klippel's work, but don't really see why Klippel is important here?
Notching it out will do a little with the lower harmonics.
They still will be present. Look at any measured speaker incl crossover, and you will still see it.
Don't really understand even why this needs to be quoted?
Everyone who ever measured things and made their own crossovers/filters will be familiar with this phenomenon?
I happen to just had a look at D&D 8C a while back;
Dutch & Dutch 8c Speaker Review
In the distortion plots down below, you see the very typical distortion from a aluminum cone.
I have worked with similar speakers in the past, they all will give the same distortion pattern, even when filtered.
(I wish so badly that they put these distortion plots in percentage instead actually)
Notching it out will do a little with the lower harmonics.
They still will be present. Look at any measured speaker incl crossover, and you will still see it.
Don't really understand even why this needs to be quoted?
Everyone who ever measured things and made their own crossovers/filters will be familiar with this phenomenon?
I happen to just had a look at D&D 8C a while back;
Dutch & Dutch 8c Speaker Review
In the distortion plots down below, you see the very typical distortion from a aluminum cone.
I have worked with similar speakers in the past, they all will give the same distortion pattern, even when filtered.
(I wish so badly that they put these distortion plots in percentage instead actually)
Looking for clarity....We've been discussing F... Fb issues are easily viewed and explored in the Horn category...as well thewy line up with the discussion here.
Should I be concerned with Fc regarding these theories and how they might apply to a midrange?
This thread inspires good design perspective...
Should I be concerned with Fc regarding these theories and how they might apply to a midrange?
This thread inspires good design perspective...
I am gonna correct myself on one of my previous conclusions.
Which was another brain-fart at the same time.
I discovered this brain-fart by just browsing though some measurements and noticed some correlation. Result was the DOH! moment.
Because demodulation rings do multiple things, not only just the inductance vs displacement, but of-course also improving the additional reluctance force as well as reducing eddy currents. *
So for a good mid you do need demodulation rings.
*John Eargle has a good explanation of this in his book "Loudspeaker Handbook" from page 55 and on.
Which was another brain-fart at the same time.
I discovered this brain-fart by just browsing though some measurements and noticed some correlation. Result was the DOH! moment.
Because demodulation rings do multiple things, not only just the inductance vs displacement, but of-course also improving the additional reluctance force as well as reducing eddy currents. *
So for a good mid you do need demodulation rings.
*John Eargle has a good explanation of this in his book "Loudspeaker Handbook" from page 55 and on.
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OR something that just doesn't have much linear excursion and is otherwise well-designed.
As an example, note Zaph's comments for the PHL 2521 near the bottom of this page:
Zaph|Audio
As an example, note Zaph's comments for the PHL 2521 near the bottom of this page:
Zaph|Audio
No, you're missing an important point here.
Those other non-linear effects don't care about excursion, and will always be there.
One exception would be having an alnico 5 magnet instead of ferrite.
Just read Eargles book, and you will understand.
Yes, technically one could maybe go through all the trouble of hyper optimizing the magnetic circuit.
But a demodulation ring will hit a couple of birds with one stone, and is cheap, so why not using it?
Anyway, for system integrators (=99.8% of us) that is not a relevant discussion.
Those other non-linear effects don't care about excursion, and will always be there.
One exception would be having an alnico 5 magnet instead of ferrite.
Just read Eargles book, and you will understand.
Yes, technically one could maybe go through all the trouble of hyper optimizing the magnetic circuit.
But a demodulation ring will hit a couple of birds with one stone, and is cheap, so why not using it?
Anyway, for system integrators (=99.8% of us) that is not a relevant discussion.
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I'd argue that you go back and read that paper (in full, several times) from Klippel that I linked to. You would be far better off doing so. 
Ex. Inductance affects the magnetic circuit of the motor causing distortion - so even regardless of excursion it is a component of the driver's non-linear result.
-and of course other sources of distortion do (also) "care" about excursion.
Ex. Inductance affects the magnetic circuit of the motor causing distortion - so even regardless of excursion it is a component of the driver's non-linear result.
-and of course other sources of distortion do (also) "care" about excursion.
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I'd argue that you go back and read that paper from Klippel that I linked to. You would be far better off doing so.
Ex. Inductance effects the magnetic circuit of the motor causing distortion - so even regardless of excursion it is a component of the driver's non-linear result.
If you're familiar with Klippel, you would know that they say the same thing as Eargle says. Or I guess that is what you're trying to say?
I already told you I know Klippel's paper.
That paper only doesn't explain a whole lot, just summarizes things.
Back in the day we even did a course with them about all of this.
Sometimes you just have to read an explanation a certain way to make it click.
Eargle's way of writing always makes things click for me.
In fact, in retrospect I already knew, hence the brain-fart I mentioned before.
Just pointing people to different sources so they can read about it themselves.
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I am really sorry camplo, probably it's just me, but I sometimes struggle with understanding your messages.
The way I see it, is that the driver's Fs is leading.
In relationship with the cone excursion like Mark says.
In a closed box the resonance frequency naturally always will be higher, unless you force it with a linkwitz transform or other types of EQ.
Using the system beneath the drivers Fs will cause the same problems.
Only with a vented enclosure (or TL/horn) it is possible to extend this a little because of the dip in the cone excursion.
I think this can also be seen in the distortion measurements of BR systems.
Obviously not taking additional non-linearities into consideration. There is no free beer in this.
The way I see it, is that the driver's Fs is leading.
In relationship with the cone excursion like Mark says.
In a closed box the resonance frequency naturally always will be higher, unless you force it with a linkwitz transform or other types of EQ.
Using the system beneath the drivers Fs will cause the same problems.
Only with a vented enclosure (or TL/horn) it is possible to extend this a little because of the dip in the cone excursion.
I think this can also be seen in the distortion measurements of BR systems.
Obviously not taking additional non-linearities into consideration. There is no free beer in this.
Or maybe you mean what happens below the frequency of the box itself?
Well in general, more cone excursion will create more non-linear behavior of the box.
Or in other words, the smaller de box (higher Fs), will create also more non-linear behavior.
This is because of the (non-linear) compression of the air -> creates asymmetric load on the speaker.
Luckily that is only 2nd order, so it isn't that bad.
As what happens below the box's resonance frequency?
(not taking the driver's Fs into account).
I can't think of any things at the moment.
edit: Well, except some practical limitations, to get the sealed box stiff enough (= Q of the sealed box)
Well in general, more cone excursion will create more non-linear behavior of the box.
Or in other words, the smaller de box (higher Fs), will create also more non-linear behavior.
This is because of the (non-linear) compression of the air -> creates asymmetric load on the speaker.
Luckily that is only 2nd order, so it isn't that bad.
As what happens below the box's resonance frequency?
(not taking the driver's Fs into account).
I can't think of any things at the moment.
edit: Well, except some practical limitations, to get the sealed box stiff enough (= Q of the sealed box)
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The higher Fb or Fc I think you mean....
So at Fc and Fb there is pressure. At Fs there is no pressure or at least no where near fb/fc otherwise, there must be evidence at Fs.
So excursion is the star of the topic....I've had that drilled in my head enough and you guys, in this thread, have found new way to end up here again lol. I enjoy the scenery on this route.
It exposes the relationship of BL vs resistance (whether from pressure or suspension or both)
BL is not static? It falls as diaphragm leaves center? So thats a problem as well.
Distortion created at frequencies with larger excursion transfer to the frequencies that are being produced at the same time but require less excursion. So keeping a midrange 1.5X above Fb/fc is misleading unfortunately. Keeping midrange away from more than 1-2mm of excursion is the most revealing answer, unless we are saying something more than excursion is a problem at Fb/fc, like pressure for example.....Fb/fc does not equal a final excursion..... Desired Spl vs Sd equates to this. Its a different way to look at it.
Isobaric must lower distortion caused by Resistance. I always read that isobaric has no benefit for midrange...I would agree with this because of the small excursion needed for midrange (where Le dominates) in a lot of cases but if it lowers distortion in bass excursion then this will be less distortion transferred to any midrange it is also producing at the time. I wonder if Isobaric helps to keep the woofer dampened in the face of cabinet reflected energy transferring back out of the woofer?
Hmm I forget or don't know how to calculate that Frequency.
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