technical 'Q'uestion (the Q of an organ pipe)

[Jamie]

It is a difficult one...Everywhere you go and think you have it,something else comes up.At the moment I am looking at Leslie 'Old' tube horns. That last link threw me off in another direction.

'Q'

Q is the formula for what happens electrically and physically at resonant frequency. Q is related to how slowly a natural vibration dies down. Q is a neat term that combines many elements of speaker design, so it's an important term to speaker designers.

Q is important to the woofer because in a speaker system where the Q is too high, you'll get a whomp in the bass. If a speaker system's Q is too low, then the bass output is relatively weak, because frequency response is highly damped in that region.

The best Q for a speaker to have is one that gives flat response down to the resonant frequency.

If you do nothing to a speaker but make the cabinet smaller, you increase stiffness and therefore Q goes up. But Q is not a word for stiffness alone. It's a ration involving mass, stiffness, and resistance (or damping). Designers often juggle these three factors. Good bass is not enough. Good bass with uniform frequency response and spherical wave-form is the goal. Obtaining that goal without too much sacrifice in efficiency is the challenge.
______________________________ will be back a bit later..... Yeah 'Challenge'.Jamie
I put that in for a reason LOL now can't remember why.
have not had any sleep for 18 hours so and be up in the early hours of the morning.

[Pamadu]

Just to confuse all of us:

a "Q" sound calculator:

http://www.csgnetwork.com/speakerqestcalc.html

I need a Pamadu/Paul.... I also notice a lot of Other Calculators on this Page

[**DONOTDELETE**]

That is a differant 'Q' than the one Jamie talks of. (which I think is the same one used with organ pipes). It brings out a good point. 'Q' (quality factor) can be anything you want (depending on the 'quality' you are looking for.) 'Q' in one system could concievably be 1/Q in another !

[Jamie]

Q factor
From Wikipedia, the free encyclopedia:

http://en.wikipedia.org/wiki/Q_factor

And that's the Confusion.!!!!!!!!! I think. when reading & asking. 'Q' CAN be anything you want.????????? etc etc as you have said.
Jamie.

[Pamadu]

This is the "Danske" link as above. May help more for some people:
http://da.wikipedia.org/wiki/Godhed_%28elektronik%29

tak. Pamadu/Paul.

[hitsware]

>And that's the Confusion

I don't think so if we are sure we are speaking in the context of organ pipes. 'Q' = Fc / Fp .....VERY associated with 'scale factor' .......

[Jamie]

Your Quote 'Yea. Seems in this disipline 'scale factor' is used much more than 'Q'. It's a new system to me, but the results should come out equivalent. The 2 (sf (interestingly there is a 'sf' in speaker building, but it is 'size factor' and pertains to where in the room you locate your speakers)) and Q are definately related.'

The formula is Correct. Q = Fc/Fp . but it does make a big difference on the type of pipe etc.and Accoustics etc. but agree that the when using this formula it should come out right.....but there are some other reasons,I have found.and also been told. Will be back tomorrow after all this Birthday thing is over....I have to sober up as well. Jamie.

[Pamadu]

Just have a look at this Link (there are 15 Pages to click at the Bottom). It gives a little about The Physics of Organ Pipes......However,by No Means The answer we seek.

http://rjweisen.50megs.com/fluepipe1_001.htm

It does help to see a few things. Cheers Pamadu/Paul.

[hitsware]

What exactly is 'cutup'? Simply the opening in the pipe (assuming a closed pipe)? Yea....a toroidal pipe

[Jamie]

'cutup' is:
Completed pipes are ready to be voiced. Voicing is the process of adjusting the physical alignment of the critical parts (upper and lower lips, languid, etc.) to get the desired sound.This process begins by establishing the CUTUP, which is the distance from the lower lip to the upper lip of the pipe. Proportional dividers are used to etch a line across the upper lip of the pipe. Principal stops are often cut up 1/4 of the width of their mouth and Flutes are often cut up 1/3, but this depends on the tone desired. Higher cut ups increase the power of the pipe at its fundamental and decrease its upper harmonics.
see: http://www.ruffatti.com/ruffatti_pipes.html

Jamie

EDIT;
see also: http://mmd.foxtail.com/Archives/Dige....03.24.05.html (Last Paragraph)

Mr Bullock at Dallas Pipe Organs answers a lot of Pipe organ Difficult Questions. Commodore Pamadu knows him and will direct him to here,and see if He can have some input as well....He will tell you that 'Builders' guard their Voicing/Scales like Fort Knox....and we modern builders are really compiling the parts made from around the world.
'Compilers' we are. lol. as there are ONLY a FEW Pipe Making Workshops now in the World. One here in Australia.Was 'Fincham's' Organ Builders.in Victoria down south.It is now used by a Queensland Builder,so should not have much trouble getting on to them.(Fingers Crossed)

[hitsware]

http://mmd.foxtail.com/Archives/Dige....02.04.01.html

http://www.rose-hulman.edu/~moloney/...icalPipes.html

http://people.bu.edu/mbutulis/pipes.html

http://scienceworld.wolfram.com/physics/Q.html

http://mmd.foxtail.com/Archives/Dige....11.05.03.html

here's some links I've 'compiled'
Thank You !

[Pamadu]

Have seen all those links and the one to look at closely,because we are dealing with the "Damping of Harmonics" (Plenty at Bottom but less at Top as in your First Posts) is:
http://scienceworld.wolfram.com/physics/Q.html
Also try your Tecnichal Library for Audsley "The Art of Organ Building" (2 Volumes) also "The Physics of Organ Pipes" & basically "Q" can be anything....depending on the
Discipline you are Working in.
Having a few days to catch up on Music....and Jamie is off to Melbourne,Victoria...Next week. He will be seeing David Fincham while there and He is about the Only Guy left in Australia who can probably rattle it all off. His Father George Fincham would have known.I have contacted Dallas Pipe Organs,and await their reply.
Cheers or too much Cheers. hehehehe Pamadu/Paul.
P.S. Let's Hope that a few More come in on this....They should....as it is all over The Web.!!!!!!!!!!!!!!!

[Contratrombone64]

Now this thread needs to be read, then re-read, etc etc until absorbed. Obviously my cerebral capacities are too low ... most vexing.

[Corno Dolce]

Yes, CT, it is a most invalueable knowlege one should know in order to be an adept organbuilder.

Cheers,

Corno Dolce