about driver Q and how its not relevant to anything
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 13th February 2008, 11:07 AM #1 Account Disabled   Join Date: Dec 2007 about driver Q and how its not relevant to anything
 13th February 2008, 12:04 PM #2 diyAudio Member   Join Date: Jan 2006 Location: Herne I wouldnt consider this trolling, so be at ease I think you had an important insight, namely that an individual TS parameter like qts has not much meaning on its own. Only in combination with other paramters, it can be used to evaluate a driver for a specific purpose. On one hand, thats a rather obvious thing, as every equation set you use to design a specific enclosure has more than one variable, on the other hand, i also used to look at individual parameters, when i began my speaker building journey. So its a very understandable thing, this realization. It has to come sooner or later, if you use the math.
 13th February 2008, 06:16 PM #3 diyAudio Member     Join Date: Jan 2006 Location: Avalon Island You might consider the AES preprint (#1307) by Pat Snider of Speakerlab where he proposes the parameters Fs/Qt and Vas*Qt^2 Back in Nov '77 58th convention __________________ Just because you can't hear it doesn't mean no one can.
diyAudio Member

Join Date: Aug 2005
Quote:
 I think you had an important insight, namely that an individual TS parameter like qts has not much meaning on its own. Only in combination with other paramters, it can be used to evaluate a driver for a specific purpose.
Important insight... I think not. Mms and BL are just as useless on their own. I am still waiting for you to provide an equation that would allow someone to input Mms and BL and get a box size/tuning.

Qts is not a mathematical construct, it is a total damping factor. I would try and explain it but you seem to have an aversion to learning new things.
Vas and Fs could be explained, but you don't seem to want to accept that the 10's of thousands of people around the world including engineers who design speakers might know what they are doing, because that would imply that your unsubstantiated theory is wrong.

"Q is only the best example of a parameter which people feel like they understand but they really don’t. There is a lot of talk of how “High Q” drivers are good for this and “Low Q” drivers are good for that … all of that is COMPLETE NONSENSE."
Complete nonsense huh, your lack of understanding does not make it nonsense it makes you ignorant.

"As much as EBP is an improvement over Q it still doesn’t tell you something very important – volume of the box you will need. To understand this one must only consider a case of isobaric loading. In an isobaric setup FS and Q (for the combination of two drivers when considered as a single driver) both remain unchanged so EBP remains unchanged but box volume requirement is halved.
What is it that enables an isobaric alignment to work in a smaller volume? It is certainly not Q because Q remained unchanged. The answer is – it is the increased BL."

Hey, way to just arbitrarily leave out Vas which explains the Volume requirement change and just throw in BL.

"I just made up a parameter X for fun and it’s at least a hundred times more useful than Q. In fact parameter X may be the most useful parameter ever and nobody even thought of it. Sometimes I amaze myself."
I think I found the underlying problem here.

"After all a driver is just a motor driving a mass where BL is the motor and MMS is the mass. When the mass begins to interact with the box it enters a resonance which the motor needs to control."

Not to nitpick but there is also the suspension, and the motor has some electrical damping, the suspension provides mechanical damping, together guess what you get...Qts! Low Qts means overdamped-earlier bass rolloff, high Qts means underdamped-hump in the response. The "mass" is attached to a springy suspension, hey wait a mass and a damped spring, that might lead to a resonant frequency (Fs)
Wow we have a resonant system with a specified amount of damping, hmm, all we need to do is determine how it will interact with a volume of air around it. If only there existed a parameter that compared a certain volume of air to the compliance of the drivers suspension, if there was maybe they would call it Vas.

And maybe believers of this "nonsense" would use those three parameters to model woofers and predict their response.

Could you please pick up a book? Loudspeaker design cookbook might help you understand this stuff, if you want to learn that is.

__________________
Conventional methods yield conventional results

 14th February 2008, 01:48 AM #5 Account Disabled   Join Date: Dec 2007 LOL @ nunayafb i left out suspension on purpose in fact there is now a second post by Troll in that thread explaining that bit ...
Account Disabled

Join Date: Dec 2007
Quote:
 Originally posted by MaVo On one hand, thats a rather obvious thing
not to most people. people like when things mean something. they want Q to mean something ... they want it so bad that often they will not be deterred by silly things like facts.

for example to nunayafb Qts is a "total damping coefficient" and i have no doubt that when many people hear "total damping coefficient" they begin to think of it in terms of those words, not in terms of the actual formulas that define it.

it is not only in politics where words are used to hide the meaning.

 14th February 2008, 02:14 AM #7 diyAudio Member   Join Date: Aug 2005 You are a true BS artist, apparently you are not here for any other reason than to cause trouble so I am done with you. Funny how everything you said about me is actually a description of you. Everyone knows you are wrong because you keep refusing to provide evidence. Get over yourself.. __________________ Conventional methods yield conventional results
 14th February 2008, 04:15 AM #8 frugal-phile(tm) diyAudio Moderator     Join Date: Oct 2001 Location: Victoria, BC, NA, Sol III Blog Entries: 5 Standard T/S parameters are mathematical constructs based real physical speaker parameters with the purpose of making it easier to calculate box alignments (a calculator was a very expensive & expensive appliance in those days, sliderules ruled). BL is a real parameter, Vas is a construct. If you want to read a book, read Leo Beranek dave __________________ community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi p10-hifi forum here at diyA
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Join Date: Dec 2007
Quote:
 Originally posted by planet10 BL is a real parameter, Vas is a construct.
exactly.

diyAudio Member

Join Date: Nov 2003
Location: Brighton UK
Quote:
 Originally posted by vasyachkin exactly.
Hmmm .....

This thread is as boring and stupid as it gets.

Discussing just exactly how people who do not understand something
actually misunderstand it is pointless, as is the title of this thread.
How you think that "how stupid you think people are" is an interesting
topic is quite beyond me.

As for driver Q not being relevant - idiotic.

/sreten.

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