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Dvc And Qts

Old May 30, 2006 | 03:49 PM
  #1  
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Dvc And Qts

Looking on the internet there seems to be a difference of opinion whether or not the qts of a dvc sub changes or not depending on if it is wired in series or parallel.
Some manufactures list a different qts for series wired and another for parallel.
My question is did anyone build a box with a listed qts in mind and then changed the wiring (parallel to series for example), and the frequency response and sound was noticably different?
Old May 30, 2006 | 06:40 PM
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yes it does, ill see if i can find a link to an artical.
Old May 30, 2006 | 07:01 PM
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Here are some articles saying the qts remains unchanged

http://www.woofertester.com/dvc.html

http://www.diysubwoofers.org/talkshop/messages/25998.htm

I thought the qts changed because the qes halfed in series wiring and therefore changes the qts

EDIT: A light just came on (i think) the radio shack book that is stated as being wrong in one of the links does say qes is halfed, but they are comparing it to driving one voice coil of a dvc sub.
In the book the the qes is the same for a series or parallel wired sub but is half to the same sub running one coil.

Last edited by abnormal72; May 30, 2006 at 07:19 PM.
Old May 30, 2006 | 07:19 PM
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http://www.caraudio.com/forum/showthread.php?t=139750&highlight=factor+forum
Old May 30, 2006 | 07:52 PM
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thanks for the article, they seem to conflict each other though , i'll have to try wiring a sub both ways for myself and see if i can hear a difference.
(not very scientific)
Old May 31, 2006 | 03:10 PM
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The Qts should not change. There are still two coils and one permanent magnet in either wiring configuration. IF one does not change the amp though then the amount of power in the coils for sure changes and that would cause a difference in performance.

There may be a MINOR change in Qes depending on how the coil is wired but I would be shocked if it was even close to audible.
Old May 31, 2006 | 03:13 PM
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Originally Posted by abnormal72
thanks for the article, they seem to conflict each other though
yeah i dont really think i beleave everything wrote in that thead. i used to have a differnt link but i cant seem to find it

Originally Posted by Dukk
There may be a MINOR change in Qes depending on how the coil is wired but I would be shocked if it was even close to audible.
dukk you are proby right as usual
Old May 31, 2006 | 06:21 PM
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well, to give you a slightly scientific viewpoint:

Qts = Qes*Qms/(Qes+Qms)

and
Qes = Re*Sqrt(Mms)/(BL^2*Sqrt(Cms))
and
Qms = Sqrt(Mms)/(Rms*Sqrt(Cms))

so, we can clearly see that in order to change Qts, Qes or Qms would have to change.

in order to change Qes, there would need to be a shift in Re, Mms, BL, or CMS. since none of these occur, then we know that Qes does not change.

in order to change Qms, there would need to be a shift in Mms, Rms, or Cms. since none of these occur, we also know that Qms does not change.

therefore, Qts will not change.
Old Jun 1, 2006 | 07:43 PM
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Talking

/\...well, if you're going to get technical about it.....
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