'Nother question [message #44203] |
Sat, 20 March 2004 09:27 |
BillEpstein
Messages: 886 Registered: May 2009
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Illuminati (2nd Degree) |
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When they say "purely resistive load" what does it mean? Similar to the Piezo which doesn't require a crossover? If I wanted to use this thang on a Theatre 4 above, say, 8-10,000 Hz what would it need in the way of crossover parts? Would just a 1.5uF Cap do?
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Re: 'Nother question [message #44205 is a reply to message #44203] |
Sat, 20 March 2004 12:15 |
wunhuanglo
Messages: 912 Registered: May 2009
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Illuminati (2nd Degree) |
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It means the load is constant, like a resistor, and not frequency dependent (reactive) like a loudspeaker voice coil which combines resistance and incuctance. I think first order XO at 9KHz is 4.5uF
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How is this possible? [message #44207 is a reply to message #44205] |
Sat, 20 March 2004 12:43 |
Dean Kukral
Messages: 177 Registered: May 2009
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Master |
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Trying to remember my physics. Current flows somehow ("no spiders") causing the sheet to move, causing back emf - an inductive field (inductance), if I remember correctly. I don't "think" this is any different from a coil, but I am getting old...
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Re: How is this possible? [message #44208 is a reply to message #44207] |
Sat, 20 March 2004 13:21 |
wunhuanglo
Messages: 912 Registered: May 2009
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Illuminati (2nd Degree) |
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I'm not sure what you mean. How is it possible for a load to be purely resistive? I dunno. I've seen that claim somewhere in the past, but I can remember for the life of me what sort of technology was involved. I wasn't trying to say a conventional cone speaker is a purely resistive load - I was trying to say how it contrasts with that concept.
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Re: How is this possible? [message #44219 is a reply to message #44212] |
Sat, 20 March 2004 22:29 |
Dean Kukral
Messages: 177 Registered: May 2009
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Master |
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If I remember my physics [and it has been a long time :( ], I don't think that "Inductors are coils," is quite true. ("Coils are inductors," is correct.) Any time current flows into a wire, a magnetic field develops around the wire. The only difference between a straight wire and a curved wire is that the curved wire concentrates the magnetic field and provides mutual self-inductance to the wires which are now side by side. That is why I said that I don't see how a changing current in a wire (or whatever they use?) can be a purely resistive load. Perhaps the inductance is considered negligible compared to that of a voice coil.
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