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Old 14th June 2007, 12:28   #6181
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or you can use these three values for the manual to calculate the senstivity of the driver.....

Fs , Vas , Qes

HiFi Speaker Design mhSoft 2007
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Old 14th June 2007, 12:43   #6182
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What is VAS and QES?
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Old 14th June 2007, 12:53   #6183
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Quote:
Originally Posted by tsk1979 View Post
What is VAS and QES?
Fs: Resonant frequency of loudspeaker moving mass (in free air)
Qes: Electrical Q of loudspeaker
Qms: Mechanical Q of loudspeaker
Qts: Total Q of loudspeaker
Vas: Equivalent air volume of moving mass suspension

Soruce: Measuring Loudspeaker Driver Parameters
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Old 14th June 2007, 13:50   #6184
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Quote:
Originally Posted by low_bass_makker View Post
or you can use these three values for the manual to calculate the senstivity of the driver.....

Fs , Vas , Qes

HiFi Speaker Design mhSoft 2007
The Driver Reference Efficiency formula gives a figure of 84.2142 db for JBL P1222
For Kicker, the brochure doesnt say anything about Qes. Qms value also not given hence can't calculate Qes. Only Qts value is given.
(with Qts value instead of Qes, The figure for S12L5 is 88.97 db (I know its a wrong way))
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Old 14th June 2007, 14:06   #6185
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Originally Posted by santosh.s View Post
Actually only numbers specified as dB @ 2.83v/1m should be called "sensitivity", whereas the number dB @1w/1m should better be called "efficiency". The first number gives an idea as to how load a speaker will sound when driven by a given amp, irrespective of speaker's impedance. If you are comparing the 2nd number then you will have to consider its impedance, because the amount of power it can extract from the amp will depend on that. Lower the impedance, more will be the power fed by amp. But you need to be aware of how low an impedance your amp can drive safely.
Very true. Couldn't agree more.

Would like to mention that these numbers are even more fudged when concerning dual voice coil drivers.
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Old 14th June 2007, 14:35   #6186
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Actually only numbers specified as dB @ 2.83v/1m should be called "sensitivity", whereas the number dB @1w/1m should better be called "efficiency".
Both values were quoted as 'sensitivity' in their respective catalogues.
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Old 14th June 2007, 14:44   #6187
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Both values were quoted as 'sensitivity' in their respective catalogues.
This is common and it may lead to confusions. Word "should" in my post could have been in bold letters too!
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Old 14th June 2007, 18:50   #6188
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Navin Sir,
Latin and Greek can only be learnt here for free. I do try keeping up, but at times like this, words like these leave me shaking my head in utter despair.
And I thought music was only waves of pain and pleasure.
ism; Know the language of the Gurus to know anything at all.
hi rishi,

its a small request sir, it would be great if you could maintain some space between your post and your signature as sometimes its difficult to understand your post and it creates confusion. well dont know about others but this happens to me sometimes. i mean no offense to you bro just a suggestion.

thanks in advance
clip


navinji.

thanks for explaining. any tips on fiber glassing? any tutorial online or any book s you reccomend?

thanks
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Old 14th June 2007, 19:05   #6189
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it is not on fiber glassing but something similar.

http://www.team-bhp.com/forum/diy-do...-tweeters.html
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Old 14th June 2007, 20:22   #6190
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All I learnt about fiber glassing was done during a stint in tthe 90s when I was making hover crafts for Boeing Aerospace, the US Navy, Kodak, Mead paper, etc...I have not yet read a book on audio (no Dickasons or Weems) much less a book on fiberglass.
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Old 14th June 2007, 21:10   #6191
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Quote:
Originally Posted by navin View Post
All I learnt about fiber glassing was done during a stint in tthe 90s when I was making hover crafts for Boeing Aerospace, the US Navy, Kodak, Mead paper, etc...I have not yet read a book on audio (no Dickasons or Weems) much less a book on fiberglass.
(I wrote a post right after Clip's request on FG, but isn't appearing anywhere!?! Yikes, will look really funny if it appears later)
Boss, your practical knowledge would be far more useful than books - and FG for hover-craft would be the same as FG for audio, no? Of course the quantities mixed at a time might be far less and even the resin may be different from 90's to now, but phir bhi chalega!
BTW, are you planning to write a book on where all life has taken you? I'll queue up to buy the first one - I have a feeling it will be like a Jules Verne book.
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Old 14th June 2007, 22:58   #6192
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I have a feeling it will be like a Jules Verne book.
Like 20000 league under the sea...

Last edited by low_bass_makker : 14th June 2007 at 23:00.
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Old 15th June 2007, 11:42   #6193
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I dont think we are considering teh electrical characteristcs of the cables. Many of these exotic cables might have similar electrical characteristics but still sound different.
I thought since they carry audio only in electrical form, it must be related to electrical characteristics. In my wild imagination, I was wondering whether contacts between different materials would lead to some problems...and that they might have pronounced effect only for "small" (weak) signals! But it seems these exotic guys are bothered more about cable itself than contacts. Anyway, when it comes to non-electrical, artistic qualities, there is no question of those being scientifically measurable

Last edited by santosh.s : 15th June 2007 at 11:43.
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Old 15th June 2007, 12:08   #6194
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Originally Posted by santosh.s View Post
But it seems these exotic guys are bothered more about cable itself than contacts.
No no baba, end contacts are taken as seriously as the cable itself. I do not know of any cable companies that don't take termination seriously.
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Old 15th June 2007, 12:14   #6195
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Originally Posted by Sam Kapasi View Post
No no baba, end contacts are taken as seriously as the cable itself. I do not know of any cable companies that don't take termination seriously.
I meant, as far as "signatures" of various materials are concerned (not the overall effect)
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