Funniest snake oil theories

Status
Not open for further replies.
Jump to Latest
#2,407
jan.didden said:
It'll move until the elcectromotive force equals the spring force. As Vacuphile notes this is not linear so doubling the DC doesn't mean it moves twice as far - the suspension resistance is not linear and neither is the electromagnetic motor.

Now if you change the DC faster and faster, you'll find that the cone hasn't moved to where it would like to move, before you have reversed or changed the DC. But now it actually is AC of course....😉

Jan
Click to expand...

There is NO spring force as this is a pure electro mechanical system.
With DC = 0 volt applied the voice coil are in the mid position.
A positive current moves the voice coil out to the position the current demands - the same for a negative current - just the opposite direction.

If you use a potentiometer connected to + and - with the wiper DC coupled to a DC coupled amplifier then you can adjust the cone from the outmost to the inmost position and the cone will stay where the input reference are set.

No magic - only pure reality - but ordinary limitations must be eliminated 🙂
 
#2,410
jan.didden said:
It'll move until the elcectromotive force equals the spring force. As Vacuphile notes this is not linear so doubling the DC doesn't mean it moves twice as far - the suspension resistance is not linear and neither is the electromagnetic motor.

Now if you change the DC faster and faster, you'll find that the cone hasn't moved to where it would like to move, before you have reversed or changed the DC. But now it actually is AC of course....😉

Jan
Click to expand...

Not correct - it will first move nearly to the intended position (limited by the spring force), but then the spring force will move it back and the fight between the electromagnetic and spring force will cause a resonance..
 
#2,411
vacuphile said:
Even electrostats need 'some kind of spring-power' to keep the foil centered, and electromechanical drivers need spring power to keep the voice coil centered in the air gap, so this must be an entirely new working principle. I am always open to new things, so let's hear more!

Btw, any driver would eject its vibrating diaphragm under DC if it weren't for spring power keeping it in check. In Dutch we call this kind of tale a monkey-sandwich story.
Click to expand...

Even the electrostatic drivers I have made work normal -> if the foil have 0 volt and there are a 6000 volt positive and a 6000 volt negative stator then the foil will be positioned in the middle of the two stators.
The same with a ribbon driver. No current = stay in neutral position, but a negative or positive current will move it in the respective direction.

Sometime in the mid 80ties I modified Infinity Emits and Emims, made OB versions of the Emits and removed the spring acting foil on both so they become true ribbons - Did they work properly - yes of course.
 
#2,413
OK, I got it.if I were to hold your driver in my two hands & move it front to back, I would see the cone move forward & back from its own mass.??Yes?
So the suspension applies no "centering", zeroing of the cone mass.
Only when the cone reaches the cone travel limits is there a rapidly rising "barrier", (spring)...OK got it.
So if I got this right the Qms, mechanical damping, would be very very high, greater than one, Five, Ten? Have I got this right?


__________________________________________________Rick.........
 
#2,414
RayCtech said:
There is NO spring force as this is a pure electro mechanical system.
With DC = 0 volt applied the voice coil are in the mid position.
A positive current moves the voice coil out to the position the current demands - the same for a negative current - just the opposite direction.

If you use a potentiometer connected to + and - with the wiper DC coupled to a DC coupled amplifier then you can adjust the cone from the outmost to the inmost position and the cone will stay where the input reference are set.

No magic - only pure reality - but ordinary limitations must be eliminated 🙂
Click to expand...

So how did you get rid of the springiness of the surround? Do you have a surround?

Jan
 
#2,416
jan.didden said:
So how did you get rid of the springiness of the surround? Do you have a surround?

Jan
Click to expand...

I designed my own surround shape that have close to zero spring effect in the pluss minus 6mm range (12mm peak to peak) and a slowly increasing spring effect from there up to 15mm (30mm peak to peak).
Made of pure silk.
Normally movement when playing 105dB peak are around 1 to 2mm and practically impossible to see with your eyes only.
But some effects like when someone are blowing in the microphone, or hitting the microphone can cause full peak to peak movements, natural instruments like organs, contrabass etc. may cause movements up to zero spring range, but only records that are overdone = clipping cause greater movements.

That said there are a lot of recordings that clips in the bass region and I used a long time to investigate these issues as I clearly could hear the effects, but was not sure what the real cause was...
On some records the bass clippings was a nasty experience as it felt like a car was hitting you house or a earth quake - witch I also have experienced - I both heard, felt and saw the neighbor house collapse due to a earth quake.
 
#2,417
So we have a restoring force but nothing to cause it? People need to understand that when a scientist says 'spring' he does not necessarily mean a small metal helix but almost any mechanical arrangement which imposes a force roughly proportional to displacement.

I'm still puzzling over the 'down to DC' music room, which needs an airlock and, perhaps, sweets to help people keep their eustachian tubes unblocked. Oh dear! I have just remembered: our ears are only sensitive to pressure difference so as soon as you swallow you lose the signal. Now that would create DBT listening fatigue: compare these two speakers but you can't swallow - not even a build-up of saliva.

OK, just seen latest post. A change of restoring force from near zero to something more at a particular point will cause distortion. Fortunately some of this will be subsonic so not audible. RSM?
 
Last edited:
#2,418
DF96 said:
So we have a restoring force but nothing to cause it? People need to understand that when a scientist says 'spring' he does not necessarily mean a small metal helix but almost any mechanical arrangement which imposes a force roughly proportional to displacement.

I'm still puzzling over the 'down to DC' music room, which needs an airlock and, perhaps, sweets to help people keep their eustachian tubes unblocked. Oh dear! I have just remembered: our ears are only sensitive to pressure difference so as soon as you swallow you lose the signal. Now that would create DBT listening fatigue: compare these two speakers but you can't swallow - not even a build-up of saliva.
Click to expand...

What have you been injecting 😀
 
#2,419
RayCtech said:
Even the electrostatic drivers I have made work normal -> if the foil have 0 volt and there are a 6000 volt positive and a 6000 volt negative stator then the foil will be positioned in the middle of the two stators.
The same with a ribbon driver. No current = stay in neutral position, but a negative or positive current will move it in the respective direction.

Sometime in the mid 80ties I modified Infinity Emits and Emims, made OB versions of the Emits and removed the spring acting foil on both so they become true ribbons - Did they work properly - yes of course.
Click to expand...

That's why I mentioned that even an electrostatic drivers needs a spring force (the membrane is stretched, isn't it) to not accelerate into space under DC.

I complement you on what, for the moment, is a funny snake oil theory. I hope you don't believe it yourself.
 
#2,420
vacuphile said:
That's why I mentioned that even an electrostatic drivers needs a spring force (the membrane is stretched, isn't it) to not accelerate into space under DC.

I complement you on what, for the moment, is a funny snake oil theory. I hope you don't believe it yourself.
Click to expand...

You are wrong as the spring force are NOT to control a DC = no signal condition, but only a means to limit excursion and possibly other non-linearities and resonances...
And of course the diaphragm needs to be centered between the stators to have a even / linear movement region and thus need a minimum level of stretch...
 
Last edited:
Status
Not open for further replies.
Top Bottom