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Old 13th May 2006, 23:19   #31
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Quote:
Originally Posted by Bass&Trouble
I better be in my elements. My weekend is just starting right now at 11pm on a Sat night, and it's gonna last only till tomorrow morning till I get back to work again. And I'm gonna do a Sam tonight, tank up on a few zillion bottles and figure out how to get on a horizontal basis with someone in the night!
... do tell us the X-mas achieved later.... har har har

Last edited by kb100 : 13th May 2006 at 23:20.
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Old 14th May 2006, 09:39   #32
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Quote:
Originally Posted by Bass&Trouble
I better be in my elements. My weekend is just starting right now at 11pm on a Sat night, and it's gonna last only till tomorrow morning till I get back to work again. And I'm gonna do a Sam tonight, tank up on a few zillion bottles and figure out how to get on a horizontal basis with someone in the night!
Way to go B&T, all this sound-vound is all rubbish. Intoxication and fornication are the two directions to go in. Good show
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Old 14th May 2006, 14:16   #33
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People please suggest me the box volume . And Is the sub will able to take mrd or not. Or I have to buy a low power amp for it.
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Old 14th May 2006, 14:44   #34
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Quote:
Originally Posted by low_bass_makker
People please suggest me the box volume . And Is the sub will able to take mrd or not. Or I have to buy a low power amp for it.
LBM,build the box acc. to T/S guidelines which u will know when u decide/buy the subw.
OR

Choose the model of subw [if buying ID ] and Gunbir/JB can tell you box volume....
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Old 14th May 2006, 15:59   #35
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...Looks like all the guru's are yet to get VERTICAL after yesterday's binge!
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Old 14th May 2006, 23:48   #36
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Quote:
Originally Posted by Bass&Trouble
It is a bit difficult to accurately calculate a driver's displacement physically. The manufacturer would mention this in some tech sheet. But if you insist, you could re-christen your subwoofer 'Archimedes', dip it in a tub of water...and shout 'Eureka'.
many manufacturers specify the volume their driver uses up in a box. but it can be easily approximated by using the volume of cone (1/3 Pi r2 h) where r = diameter/2.

BTW I find msot of the maths required for speaker design to be just about challenging enough to don in one's head. kinda stuff you can do if one is in the bath or driving home. anything more complex needs a pen and paper.

Last edited by navin : 14th May 2006 at 23:51.
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Old 15th May 2006, 14:21   #37
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... B&T.... HALOOoooo??.... You dehydrated???
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Old 15th May 2006, 14:27   #38
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Quote:
Originally Posted by kb100
... B&T.... HALOOoooo??.... You dehydrated???
Hi hi. I'm alive.

Navin, you could get the displacement due to the conical part of the cone from your theory, but it would suffice poorly for a subwoofer with a robust die cast magnet, terribly overhung voice coil and a triple stacked magnet. Although one could approxiomately account for them too.

Best thing to do if the driver displacement bothers you a lot, kb100, is to mount the driver 'ulta' with the cone facing inwards. No tension!
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Old 15th May 2006, 14:42   #39
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Quote:
Originally Posted by navin
many manufacturers specify the volume their driver uses up in a box. but it can be easily approximated by using the volume of cone (1/3 Pi r2 h) where r = diameter/2.
.
What about the volume of Motor Assembly (Magnet) and Basket, which is cast type in most of the good subwoofers today and has more volume than stamped ones.

The driver displacement volume is generally mentioned in the subwoofers manuals.
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Old 15th May 2006, 21:37   #40
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Yaaro I want specs not ulta and shidha. Get serious people we have to ICE some thing....
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Old 15th May 2006, 22:56   #41
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Quote:
Originally Posted by Autophile
What about the volume of Motor Assembly (Magnet) and Basket, which is cast type in most of the good subwoofers today and has more volume than stamped ones.

The driver displacement volume is generally mentioned in the subwoofers manuals.
true some of the maha woofers i see today esp in car audio would need another equation i use 1/2 Pi r2 h. Note that this works when the chassis is larger than usual. One woofer I saw (displacement was given by the manufacturer) worked out to 2/3 Pi r2 h! unfortunately all that mass in the chassis and magnet did not translate to a great sound. remember since we are talking approximates here Pi = 3 and Pi2 = 10. None of that 3.1425..stuff.
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Old 15th May 2006, 23:34   #42
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Quote:
Originally Posted by navin
true some of the maha woofers i see today esp in car audio would need another equation i use 1/2 Pi r2 h. Note that this works when the chassis is larger than usual. One woofer I saw (displacement was given by the manufacturer) worked out to 2/3 Pi r2 h! unfortunately all that mass in the chassis and magnet did not translate to a great sound. remember since we are talking approximates here Pi = 3 and Pi2 = 10. None of that 3.1425..stuff.
.... duh.....
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Old 15th May 2006, 23:44   #43
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people stop discussing about the volume of Motor Assembly (Magnet) and Basket. here are the spec loud and clear . Now let us discuss about the same now......

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Old 16th May 2006, 09:58   #44
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I'd use a 40-50 liter sealed box. the recomendations are about the same (1.3 cu. ft). you'll get a Qts of about 0.7. a larger box will lower Qts and improve transient response. choose your poison. you can use a box as big as 130-150 liters (Qts of 0.5) with this woofer. hope this helps.

P.S. given that you had box specs why did you ask us? LEAP/LMS is reasonably accurate.

BTW 1/3 pi r^2 h = 1/3 x 3 x 6.5^2 x 11 = 465cu in = 7615 cc = 7.6 liters = 8 liters. JB how colse is this approximation? 11 because at 8.35" ht the cone is not complete so one extrapolates nad i used 6.5 insteald of a r of 6.25 becuase the chasis is not a pure cone.

in fact the faster way is
6.5^2 = 40 (becuase 6^2 is 36 and 40 is the closest "easy" number)
11 = 12 (becuase we know that 6.5^2 is really a bit larger than 40 so we compensate)
40*12 = 480 cu in
Now we know that 1728 cu in = 28.316 liters = 1 cu. ft.
480 cu in is about 1/3 cu. ft = 28/3 = 9 liters. (9x3 = 27).
No need for a calculator! :-)

Last edited by navin : 16th May 2006 at 10:11.
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Old 16th May 2006, 15:04   #45
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It seems you're craving for SPL! kill for that type X man! and Santro will fly without the help of engine.
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