Notice when the image gets blurry. Instead of getting blurry at the exact moment of full excursion and incursion the camera looses clarity several hundreths of a second after those 2 events! This got me thinking, whats going on magnetically to cause that, whats the BL doing, as well as impeadance. Also, wouldn't the external magnetic forces generated from the coil be greatest at full excursion and thus blur the image then?
input....
Steve
Posts: 4518 | From: Land Lord of Iggy's Head Apart Complex Tower #2 | Registered: Jan 2000
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I didn't watch the video, but are you sure that blur is caused by magnetic field or is it because of SPL vibrations of camera?
Posts: 1820 | From: Ljubljana, Slovenia | Registered: Jan 2000
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quote:Originally posted by Dr.Loudness: I didn't watch the video, but are you sure that blur is caused by magnetic field or is it because of SPL vibrations of camera?
Even if it were, why would the camera loose focus just before max excursion and just before max incursion?
[ 11-01-2002, 06:02 AM: Message edited by: Bumpin' Yota ]
Posts: 4518 | From: Land Lord of Iggy's Head Apart Complex Tower #2 | Registered: Jan 2000
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Because speaker is producing SPL at highest velocity of cone, not at highest excursion.
Posts: 1820 | From: Ljubljana, Slovenia | Registered: Jan 2000
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quote:Originally posted by Dr.Loudness: Because speaker is producing SPL at highest velocity of cone, not at highest excursion.
first a magnetic field doesn't affect light
it think it either the sound vibrating the camera OR the the camera refresh rate isn't fast enoug to catch it a TDC/BDC as they are quick moments in time
Posts: 137 | From: wilmington, DE | Registered: Mar 2002
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quote:Originally posted by Dr.Loudness: Because speaker is producing SPL at highest velocity of cone, not at highest excursion.
But wouldn't maximal cone velocity be at the normal resting point of the cone as anything farther out from that in either direction would be slowed down by the suspension....
When in the stroke of the coil, is the impeadance the lowest? Im thinking that the impeadance is lowest near full excursion/incursion and as such the magnetic fields from the coils are affecting how the video camera is recording the images on the magnetic tape.....
[ 11-04-2002, 03:32 PM: Message edited by: Bumpin' Yota ]
Posts: 4518 | From: Land Lord of Iggy's Head Apart Complex Tower #2 | Registered: Jan 2000
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i was always under the impression that when the coils at max excursion the impeadence is the lowest but i could be wrong cause im kinda new to all this
Posts: 41 | From: maryland | Registered: Nov 2002
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Not quite. The lowest impedance is where the rise due to capacitance is the same as the rise due to inductance. 10 ohms of capacitance + 10 ohms of inductance at frequency(x), then the rise above the DCR is that of the basic EMF. dcr=dc resistance of the vc emf=electro-motive force(basically meaning: pass current through the vc, a motive force will be created. Or equally, a motive force on a vc in a magnetic field will cause an opposite current to flow.
As for the video, it could be some weird resonance mode of whatever the camera is mounted on. It could(and probably is due) to the bad quality of the video.
Posts: 768 | From: Ottawa, On, Canada | Registered: May 2000
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The speaker is moving its slowest at the extremes. It is already past the control gap of the magnetic field. The speaker must then stop and change direction. This takes some time.
Also remember the speaker doesn't travel a given xdistance out ver time, only the time of the frequency is fixed.
-------------------- My 45's want fit in that slot! Posts: 1147 | From: Rowlett, TX, USA | Registered: Jun 2000
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hey to bring this up. the video just plays one cycle it is on auto loop to appear sub is playing. I think the looping is causing the blur lol
-------------------- KING KONG aint got **** on me. WOW have been gone a long time. But I am back baby. Former 2003 meca MR5 world record holder. UGLY 1991 brown explorer, BUT was able to do 151 on cert. lin x at the head rest at 42hz!(with cheap audiobahn 15s with about 60 percent of the power allowed that year. lol) Posts: 1123 | From: Indianapolis, In, USA | Registered: Jul 2001
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I took a look and what I see is bad footage looped. I have a digital camera that takes great pictures but lousy video.. and this looks like the handy work of a camera like mine... I don't think its the spl or the magnetic field..
-------------------- www.IMAGEdynamicsUSA.com "I don't know how to put this but I'm kind of a big deal." - Ron Burgundy Posts: 495 | From: The "O.C." | Registered: Jan 2003
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My guess is it's a series of still images, and they're blurred together at the transition to create a believable loop of the sub moving. The camera was not at the exact same spot for two sequential pics, so when it goes from the first to the second, the blurring is noticeable in the things that should be still. Thats just me, though.
-------------------- 1995 Grand Am GT Nakamichi CD-45z Pair of Audiocontrol EQT's Audiocontrol 4XS Crossfire TEK100.2 Illusion Audio ND-6 Crossfire VR142 Image Dynamics CD1E V.2
Looking for the following: Image Dynamics IDMAX 12" Crossfire BMF1000d or VR1000d Posts: 48 | From: Buffalo | Registered: Oct 2002
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Guess someone never took physics . In this case though, no the gravity field is not enough to affect visible light.
Posts: 1 | From: Hartford, CT | Registered: Mar 2003
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i didn't read the whole post but it probably has to do with the fact that peak SPL is created as the woofer passes through the origin ... and by the time the woofer hits the peak the sound wave has had time to propagate through the air and causes the camera to blur.
Posts: 30 | From: Canada | Registered: Mar 2002
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Guess someone never took physics . In this case though, no the gravity field is not enough to affect visible light.
LOL.......you read wrong icehawk....they were talking about a magnetic field affecting light, not gravity........a magnetic field by itself will not affect light
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