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technical 'Q'uestion (the Q of an organ pipe)
- Thread starter hitsware
- Start date
Pamadu
Civilian
Re: Jamie...... Could you hook up the * Apprentice* to this ?
A lot of people are pointing me to this link:
http://www.pykett.org.uk/how_the_flue_pipe_speaks.htm
Yes...It explains a lot....BUT most important is a Reference at the bottom of page in Section on "Pipe Scales" and especially under further reading:
3. “The Physics of Organ Pipes”, N H Fletcher, Scientific American, January 1983, p 94
Did have a copy of this,but now lost. So the search will continue.Could be worth contacting the Author of that article.(Colin Pykett)?????? Cheers
Pamadu/Paul.
http://www.pykett.org.uk/how_the_flue_pipe_speaks.htm
Yes...It explains a lot....BUT most important is a Reference at the bottom of page in Section on "Pipe Scales" and especially under further reading:
3. “The Physics of Organ Pipes”, N H Fletcher, Scientific American, January 1983, p 94
Did have a copy of this,but now lost. So the search will continue.Could be worth contacting the Author of that article.(Colin Pykett)?????? Cheers
hitsware
New member
Re: Jamie...... Could you hook up the * Apprentice* to this ?
"The reason why the natural frequencies are not exact multiples of the fundamental is because of the end corrections of the pipe, which cause it to seem rather longer than its actual length to the travelling impulses. The end corrections at the mouth and top (if open) result partly from the impulses overshooting the pipe ends somewhat, and the mouth corrections dominate those at the open end. The total end correction (mouth plus end) is greatest for the lowest frequencies and it also increases for wider pipes. These two effects taken together mean that the natural frequencies for wide pipes do not coincide well with the harmonics of the forced excitation when the pipe is sounding. The teeth of the two combs lie progressively further apart in this case, as shown in Figure 4, although this diagram has been exaggerated for clarity. This means that such a pipe does not amplify the harmonics of the forced excitation very well beyond the fundamental and first few harmonics, thereby producing a frequency spectrum characteristic of a flute."
Ya Mon! Great link. Just touches on 'Q' but the quote above is great. I've done some experiments and wondered about the weird harmonic structure.........
"The reason why the natural frequencies are not exact multiples of the fundamental is because of the end corrections of the pipe, which cause it to seem rather longer than its actual length to the travelling impulses. The end corrections at the mouth and top (if open) result partly from the impulses overshooting the pipe ends somewhat, and the mouth corrections dominate those at the open end. The total end correction (mouth plus end) is greatest for the lowest frequencies and it also increases for wider pipes. These two effects taken together mean that the natural frequencies for wide pipes do not coincide well with the harmonics of the forced excitation when the pipe is sounding. The teeth of the two combs lie progressively further apart in this case, as shown in Figure 4, although this diagram has been exaggerated for clarity. This means that such a pipe does not amplify the harmonics of the forced excitation very well beyond the fundamental and first few harmonics, thereby producing a frequency spectrum characteristic of a flute."
Ya Mon! Great link. Just touches on 'Q' but the quote above is great. I've done some experiments and wondered about the weird harmonic structure.........
Jamie
Banned
Re: Jamie...... Could you hook up the * Apprentice* to this ?
My Boss & Tutor etc.,knows Colin Pykett and later today here will email him and see what he knows about 'Q'.
It is a Good Link that. I have many more,but was hoping that 'Pipe Chat' would come up with answer by now.Will try again.It's all just
and very interesting
Jamie. Better go do some work/study now
too early here for a
but it is heating up. hehehehe
My Boss & Tutor etc.,knows Colin Pykett and later today here will email him and see what he knows about 'Q'.
It is a Good Link that. I have many more,but was hoping that 'Pipe Chat' would come up with answer by now.Will try again.It's all just
Jamie. Better go do some work/study now
Pamadu
Civilian
Re: Jamie...... Could you hook up the * Apprentice* to this ?
Will contact a Few Others today, as well as this Guy:
http://homepages.tig.com.au/~audio/audio/gadgets.htm
Cheers
Paul.
P.S. Type into Google....Q formula for sound.... many articles there as well.
Will contact a Few Others today, as well as this Guy:
http://homepages.tig.com.au/~audio/audio/gadgets.htm
Cheers
P.S. Type into Google....Q formula for sound.... many articles there as well.
Pamadu
Civilian
Re: how about elaborating on \'scale factor\' to the max ?
Sounds Good to Me "hitsware".!!!!!!
Will get Jamie to gather a few more people as well (to Join Up), and in a few days when I have a Backlog of work out of the way (after an illness).
The MAX........it is.!!!!
Cheers
Pamadu/Paul
The MAX........it is.!!!!
hitsware
New member
Re: how about elaborating on \'scale factor\' to the max ?
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.
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.
hitsware
New member
Re: Ya Mon ! ......... <|:^))
http://kosat.consultit.no/~ketil/lowther/bigfunht.html#HD_NM_14 .....
full space ... 1/2 space .... 1/4 space ... 1/8 space ... ??
http://kosat.consultit.no/~ketil/lowther/bigfunht.html#HD_NM_14 .....
full space ... 1/2 space .... 1/4 space ... 1/8 space ... ??
Jamie
Banned
Re: Ya Mon ! ......... <|:^))
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.
'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
Pamadu
Civilian
Re: Ya Mon ! ......... <|:^))
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
a "Q" sound calculator:
http://www.csgnetwork.com/speakerqestcalc.html
I need a
**DONOTDELETE**
Guest
Re: The vagaries of \'Q\'
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 !
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
Banned
Re: The vagaries of \'Q\'
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.
Q factor
From Wikipedia, the free encyclopedia:
http://en.wikipedia.org/wiki/Q_factor
And that's the Confusion.!!!!!!!!!
Jamie.
Pamadu
Civilian
Re: The vagaries of \'Q\'
This is the "Danske" link as above. May help more for some people:
http://da.wikipedia.org/wiki/Godhed_%28elektronik%29
tak.
Pamadu/Paul.
http://da.wikipedia.org/wiki/Godhed_%28elektronik%29
tak.
Jamie
Banned
Re: The vagaries of \'Q\'
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.
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.
Pamadu
Civilian
Re: The vagaries of \'Q\'
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.
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
Jamie
Banned
Re: The vagaries of \'Q\'
'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/Digests/199903/1999.03.24.05.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)
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/Digests/199903/1999.03.24.05.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.