Fully magnetic cone edge suspension with complementary characteristics to VC.
I claim the patent rights.
How big of a magnetic field do you need to get a linearish area that you're using for centering?
You know most modern drivers are using very compliant rubberish stuff, ya? At least the ones that are intended to have a wide frequency response. You seem to be talking about JBL and pro driver suspensions.
any driver which has low distortion (cone type) will have its suspensions carefully balanced with each other to provide linear excursion.
I only mention this because a lot of thinking is going into the VC/magnet maybe thinking it is thee non-linear driver source.
Very compliant rubberish stuff.... isnt apparently good enough.... distortion is poor still.... meaning very audible. One edge is held in place and pivots back and forth and if short, will draw an arc. Or attempt to.... which tugs on the cone/Vc to make its otherwise linear motion, less so. A longer 'arm' is useful. The accordion surround at edge will 'stretch and compress with the VC movement for more linear motion (lower distortion) --
Just sayin'
Maybe the magnet/VC isnt the big problem but the tail end of it.
THx-RNMarsh
I only mention this because a lot of thinking is going into the VC/magnet maybe thinking it is thee non-linear driver source.
Very compliant rubberish stuff.... isnt apparently good enough.... distortion is poor still.... meaning very audible. One edge is held in place and pivots back and forth and if short, will draw an arc. Or attempt to.... which tugs on the cone/Vc to make its otherwise linear motion, less so. A longer 'arm' is useful. The accordion surround at edge will 'stretch and compress with the VC movement for more linear motion (lower distortion) --
Just sayin'
Maybe the magnet/VC isnt the big problem but the tail end of it.
THx-RNMarsh
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Yes distortion is higher in audiophile drivers. But they play a much larger frequency range. That's the price you pay. If you look at all the pro drivers with lower distortion, you don't get 5-8" drivers playing into the 30hz. All the easy solutions involve increasing the size (like an M2). And they have that cone edge suspension/surround that acts like a compression brake - which must be more valuable than some linearity to pro sound guys.
Would it be possible to have a guide slick enough, that you didn't have to lubricate with graphite or something every song?
Would it be possible to have a guide slick enough, that you didn't have to lubricate with graphite or something every song?
???
How can-you center a voice coil when there is no signal in it with a magnetic field? It is copper or silver ....
Good start. a lube and ferro-fluid in one, maybe? or 3-4 Teflon buttons at top and bottom of VC form?
-RM
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photoelectric switch feedback that Keantoken mention could be possible. Although I actually am back to thinking it requires a switch that extends to the Xmax in both directions... perhaps I'm wrong but I can't see around that yet.
There are two centering issues here.
The suspension has to apply a restoring force to keep the vc centered on the axis of movement. Otherwise it can drift back and bottom out, or forward out of the gap.
If you try to tailor the gap field such that more BL product compensates against the pull, it will exaggerate the vc return when signal polarity changes, so that's out.
Perhaps one could put say, a sensing coil embedded in the vc former such that the spider restoring force could be compensated out. Hmm, I seem to recall somebody mentioning that construct in this thread.
And the active comp would keep track of vc position, so would not allow it to drift in or out.
As to centering the vc between pole and plate, an active solution would be very difficult . If a shorting ring were superconducting, it would repel the vc. Course, the eddy currents would be rather interesting...as in permanent.
Jn
The suspension has to apply a restoring force to keep the vc centered on the axis of movement. Otherwise it can drift back and bottom out, or forward out of the gap.
If you try to tailor the gap field such that more BL product compensates against the pull, it will exaggerate the vc return when signal polarity changes, so that's out.
Perhaps one could put say, a sensing coil embedded in the vc former such that the spider restoring force could be compensated out. Hmm, I seem to recall somebody mentioning that construct in this thread
.And the active comp would keep track of vc position, so would not allow it to drift in or out.
As to centering the vc between pole and plate, an active solution would be very difficult . If a shorting ring were superconducting, it would repel the vc. Course, the eddy currents would be rather interesting...as in permanent.
Jn
Hi John,
How about a capacitive sensor? Or to be off the wall, an LC oscillator where the frequency is well above our hearing range and the L is the voice coil? The phase might tell you on which side of the pole you're on. I'm not sure about the details on how it would work - or even if it can. You might only get information about offset from centre but nothing about which direction you're going.
-Chris
How about a capacitive sensor? Or to be off the wall, an LC oscillator where the frequency is well above our hearing range and the L is the voice coil? The phase might tell you on which side of the pole you're on. I'm not sure about the details on how it would work - or even if it can. You might only get information about offset from centre but nothing about which direction you're going.
-Chris
Why do you say it's the suspension? What data have you to support this?
Linear magnetic actuators are commonplace in industry, with forces sufficient to hold up cars, and run meters distance. That's easy.
Problem is cost.
Jn
If L is changing but monotonic, the LC could work.
I would worry about pushing ultrasonics into a vc however. Many "unknowns" there.
Jn
I believe a large box (as suggested by tournesal) for coupling the two would help a lot . I suspect a large volume would provide better mechanical compliance, just like a current drive would but mechanical.
Jn
I have to laugh at what this silly autocorrect does ..."tour seal" instead of tournesal..
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There was some discussion about that maybe a few pages into the link he subsequently posted. Loudspeaker and Headphone Handbook - Google Books
I did thought of a speaker with out suspension. It was mentioned here #1088. But mind you I only understand basic things about electronics and mechanics. So I hope no one laughs at my silly ideas. I had also posted a diagram and description of it in now suspended Indian website "theaudiophile.net" (2011 I guess).Fully magnetic cone edge suspension with complementary characteristics to VC.
I claim the patent rights.
It had an Aerogel cone with some magnet material at the rim suspended in another ring opposing magnets. The coil was concentric after the magnet and would move the cone. Now I guess it can have servo mechanism too to control it.
See picture below. The blue area at the rim (No. 1) is some magnet material on bothside and Cross section shown on right side has opposing magnets (No. 3) in a hollow ring. This suspends the cone. The light orange area concentric to rim (No.2) will have light large diameter voice coil and (No. 4) shown on cross section another magnet or coil to make the cone move. I had trouble thinking about making it stable in lateral plane of cone.
Regards
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