lol!
It really comes down to the individual. I know some pretty clueless people who all manner of letters after their name. Others that are really with it, brilliant who exist without any sign or designation.
One thing I have noticed. The truly great people help others. They are willing to pass knowledge on.
It really comes down to the individual. I know some pretty clueless people who all manner of letters after their name. Others that are really with it, brilliant who exist without any sign or designation.
One thing I have noticed. The truly great people help others. They are willing to pass knowledge on.
OK..... given that I actually have a degree in Physics.
Where, Oh All Knowing, in the Physics 221/222 textbook would this be covered?
It just so happens I have that old book on my shelf.
...
Now back to the discussion.
But that is exactly what happens. the current starts to flow immediately. There is no delay until it starts, but it starts from zero, of course.
The inductor controls the rate of change but not the starting point.
Same thing for an RC low-pass fed with a unit step. The output voltage starts to rise immediately.
That is true. Current rise is delayed, but the electron flow begins immediately. To the outside observer, there is a delay before current levels reach their full value. So there is an effective delay in the motion of a speaker cone for example, before full force is applied. How long? Depends and it may not be an issue.
Hmm... so then capacitors don't have to charge, they just snap! into voltage.
Automobiles get up to speed immediately.
The acceleration of a system is ZERO as velocity is reached immediately.
And square waves are always square... the rising edge perfectly vertical with no overshoot.
Automobiles get up to speed immediately.
The acceleration of a system is ZERO as velocity is reached immediately.
And square waves are always square... the rising edge perfectly vertical with no overshoot.
Hi Tony,
With zero source impedance, a capacitor will snap to full voltage. In the practical world, there is always series impedance that delays the voltage across the capacitor terminals. This also occurs within the capacitor structure. With zero impedance the instantaneous current would be impressive.
The real world vs isolated theory.
With zero source impedance, a capacitor will snap to full voltage. In the practical world, there is always series impedance that delays the voltage across the capacitor terminals. This also occurs within the capacitor structure. With zero impedance the instantaneous current would be impressive.
The real world vs isolated theory.
The best ways to maximize the damping factor are to use Kenwood Sigma Drive [ https://www.patreon.com/posts/prototip-moei-v-59316750 ] or Toshiba Clean Drive [ https://audio-database.com/AUREX/amp/sb-66.html ] [ https://www.patreon.com/posts/toshibka-v-aurex-100032492 ]
Attachments
Hmm... yeah... imagine the current.
I would not want to be anywhere near a capacitor that instantly charged.
At best, it would blow up... at worst it would launch itself into a 200 mph trip across the lab.
Actually, the complete theory takes such things into account, but a lot of people look at the static states not at how states change and what happens when the state changes. In electronics, I always like to show them a square wave ( or a pulse train ).. LOOK! LOOK! ringing! overshoot! delay!
I do mostly digital electronics. When it comes to "instantly reaching a new state", digital is where it's at.
We deal constantly with distortions coming from analog effects. You get those hardware designers with their simulators and emulators... then you put the whole thing in the actual circuit and things don't work because of issues with the analog electronics interactions in the board.
Ooops!
It's funny when the "firmware guy" tells them to bring in a good board designer! ;-D
Kids.
OK. Let analyze this:
Hi Sonce,
You may debate an idea reasonably, but personal comments are off limits.
Flat panel membrane (magnetostatic - like Magneplanar, or electrostatic) has mass m.
Acceleration a of that mass m is governed by the applied external driving force/signal F by this equation:
a = F/m
As there is no time t in this equation, there is no time delay in reaction of this membrane to the applied force/signal! Elementary physics!
Conventional cone loudspeaker membrane, for example, has mass of 100m (or 1000m, whatever)
If we apply force/signal 100 times bigger than the previous example (planar membrane):
a = 100F/100m = F/m
Surprise, surprise - acceleration of heavy cone (when force/signal is proportionally larger) is the same as acceleration of the light mass planar membrane!
???
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The effective mass of a planar speaker is lower than a voice coil.
Magnepans are heavier than electrostatics but still order of magnitude lower than a cone.
The reason why they are inefficient is mostly the design of the field and the size of the panel.... extremely low displacement that requires quite a bit of total motive force across a very large radiating area
But, the mass of the membrane is far lower than a cone speaker.
Again, you are using static equations for steady states, not looking at the behavior with respect to time... F(t) = m dot a(t
Magnepans are heavier than electrostatics but still order of magnitude lower than a cone.
The reason why they are inefficient is mostly the design of the field and the size of the panel.... extremely low displacement that requires quite a bit of total motive force across a very large radiating area
But, the mass of the membrane is far lower than a cone speaker.
Again, you are using static equations for steady states, not looking at the behavior with respect to time... F(t) = m dot a(t
Hi Sonce,
Your response was personal. The substance is another argument. Learn to separate the two.
Hi Tony,
Classic digital is analogue with two fixed states. We interpret it as digital. Now that we have PAM4 encoding, we have more levels to consider. Still, we call it digital.
As you've pointed out, real life is somewhat different than any abstraction we choose to apply. Things just don't really work that way.
Your response was personal. The substance is another argument. Learn to separate the two.
Hi Tony,
Classic digital is analogue with two fixed states. We interpret it as digital. Now that we have PAM4 encoding, we have more levels to consider. Still, we call it digital.
As you've pointed out, real life is somewhat different than any abstraction we choose to apply. Things just don't really work that way.
You could always use two enclosures, connected by an aperiodic vent to damp cone movement.
The more I fiddle with speakers, the more I'm starting to believe that the inductor in series with a bass driver causes a lot of issues, including reducing damping, but also affecting Dynamics.
The more I fiddle with speakers, the more I'm starting to believe that the inductor in series with a bass driver causes a lot of issues, including reducing damping, but also affecting Dynamics.
Way back in the early 1990's I designed boxes as you describe. A tower, two spaces connected with a port, undamped. They worked extremely well and we sold a bunch.
What calculations did you use ? The only ones I have found just say use an enclosure for the driver a 1/3 of the VAS, connected to a second enclosure 2/3 of the VAS.
A close box with a lot of stuffing (I use cotton wool) provides a bit of damping as well.
Hard to remember, I used Douglas Weems book as a guide. I think I designed the larger enclosure as optimal, the smaller one 1/2 that volume. I don't know if I could find the design for you. I still have the proof of concept prototypes. They used Peerless drivers, stuffed cheaper Philips in for the proof. 8" woofers.
Everyone searched for the subwoofer, it was pretty funny.
Everyone searched for the subwoofer, it was pretty funny.
It doesn't change anything.
Again:
a(t) = 100F(t)/100m = F(t)/m
If we apply force which is 100 times bigger, than acceleration (with respect to time) is the same for the heavier cone and the lighter panel, although cone has 100 times (or 1000) the mass of panel.
YES - I would call that correct.
When it comes to speakers, they are purely analog electro dynamic devices and hence have varying degrees of nonlinear distortion.
Although a little Off Topic, many people forget that speakers exhibit COMPRESSION over their full dynamic range. [ SPL range ]
This is perfectly synonymous with the realized compression of analog magnetic tape.
Many say they like the 'smooth & compressed' sound of analog SATURATION.