In a oustanding article Colin Brandsma writes about the acoustics of the uilleann pipe chanter, in The Pipers Review autumn 2004. He compares two chanters, one made in the western of Ireland in 2002 and one in Dublin 1995. Both made by professional makers.
Chanter 1: The fundamental, 1st and 2nd harmonics supply most of the acoustic power of the tone.
The fundamental and all eight harmonics contribute to the tone
The fundamental frequency has a peak power output of 8.4 x 10-4 Watts/Hz.
Chanter 2: The fundamental and 1st six harmonics supply all of the acoustic power of the tone.
The fundamental and 1st six harmonics contribute to the tone
The fundamental frequency has a peak power output of 12.4 x 10-4 Watts/Hz.
Which chanter should we like most on theoretical terms.
Mine doesn’t produce anything in watts - just a nice tone. I suppose though, that if your peat fire started to die down, you could pull out one of those other chanters and fire up an electric heater though…
The second chanter produces more harmonics, so I would imagine the tone will be rich and warm compared to the first chanter. The first chanter might be louder but tone might be thin. The more harmonics the better, but you don’t want one harmonic dominating the others.
Does watt/power out put, or whatever, refer to volume?
What is the relation of volume to harmonics, if any?
I’d like to hear a recording of each chanter, and I’d also like to know the actual name of the maker of each chanter and each reed. That might help. Otherwise, I have nothing subjective to associate with the numbers.
Actually, the more the fundamental dominates and the less higher harmonics the warmer it will be. Also, I’m guessing they each had their own reed which is much more to the point. If they could do the experiment again with the same reed and discount any tuning issues you might get some idea if what the chanter itself is contributing, still somewhat inconclusive.
Gee, somebody actually gets it. It’s hard to say without hearing them of course, but “sweet” is often more associated with pure sine waves–bell or flute-like “pure” tones. If you have all of the first six harmonics it may actually be more coarse than anything else, as you want odd ordered harmonics to be favored generally to produce “warmth” or “richness.”
It’s an ear-phenomenon, not a waveform study.
The other thing is the prominence of non-musical harmonics or just other strong harmonics may make the chanter prone to pop into squeaky behavior. Hard to say. Easy to hear.
I don’t think the odd = rich is right. My understanding , such as it is, is the opposite, or perhaps more to the point, lower harmaonics are richer than higher harmonics, in that they are less pright (lower) for one thing and they stick to the octaves, fifths and thirds for teh first five and then going to the seventh, etc.
Ther used to be an axiom in the sixties that might apply here: “If it sounds good play it.” or something like that…
Odd-numbered harmonics are usually associated with a brighter tone, whereas even-numbered harmonics are associated with a warmer, mellower tone. See the difference between a saw-tooth wave (even harmonics) versus a square wave (odd harmonics). Acoustic instruments have a mix of both odd and even harmonics, but a preponderance of one type over another is reflected in the general tone.
Isn’t it the other way around?
A square wave is comprised of an infinite set of odd harmonic sine waves and the saw-tooth of even harmonic sine waves?
Also, is it possible to compare the sound characteristics of two chanters by frequency analysis of the harmonics? I haven’t read the article so I don’t know how this experiment was done, is it available on line?
A few questions come to mind:
Was the same reed used in both chanters?
From what I understand the chanter will affect the fundamental frequency of each note but most of the harmonics will be generated by nonlinearities in the flow through the reed. So an analysis of harmonics will relate more to the differences of the two reeds than the chanters.
Or have I got this wrong???
Double reeds create lots of harmonics and the amount and magnitude of these harmonics should be different for different notes as the air pressure will be different. The distribution of harmonics between the two chanters may therefore vary with different notes. It would be interesting to see the first momentum of the frequency spectrum for a scale played on the two chanters as it would relate to the “center of mass” of the spectrum. Simple measure so I’m sure someone has done it.
BTW: About watts and relative acoustic power, I think 1 milliwatt ~ 80dB at a distance of 1 meter from the source.
Basically how I remember it but mostly from discussions on “clean” distortion from a stack of tubes as opposed to transistor Grunge pedals etc. But my point is, more isn’t necessarily better, probably not better above the first few and as I said, which ones become prominent is a factor more than just how many you have mixed in there.
And no, it doesn’t describe at all the “quality” of the chanter’s tone to compare waveform analysis unless you have a bank of given “master” chanter waveforms from which to declare a “good” chart as opposed to a “bad” chart at least–and of course the whole continuum of tonal qualities in both those ranges that are entirely a matter of taste.
Yup. Bass-ackwards. I had to drag out the books and, looking at the dates on them, realized its been 30 years since I studied this stuff. Where’d the time go?
the bottom line is It’s all in the reed…you can tell a lot from its crow ..“thats from an old oboe player”. Heinz Holliger did a great deal of research in double reed annalysis which may be worth looking for if anybody is interested. He did the whole osciloscope thing and had the resources to persue this. He approached it scientifically and methodically. I know its all in the reed. The instrument will colour this information but "it has to be in the reed " to come out the end of the chanter. Perhaps a good test would be to take your chanter and rig up a trumpet mouthpiece to it . Now blow into it and measure the sound on the oscilloscope. Now do the same to the next chanter. Measure again. Now the only question is “My lips or yours”
This is like trying to describe how to scrape the perfect reed.
My 2 cents
You sound as bad as me djm, I still have college text books dating back about 25 years. My wife and I were just going through boxes this past week, pulling out old physics, chemistry, and calculus texts to get rid out. My wife is even worse about keeping that stuff than I am. And I never get the notion to go peruse those books for any enjoyable reading. I did like physics though.
Douglas, I never finished high school. I read up on that stuff because I wanted to understand synthesizers (of which I still have a few that still work!). Being self taught coupled with the rapid degeneration of my few remaining brain cells leaves lots of room for compilation errors. :roll:
I have a synthesizer, an Akai AX80. It was pretty good for the time and still works great. I do remember reading about sine waves at that time too. In fact when this post came up I thought about checking those books out to try to decipher this.
P.S. college is all about destroying brain cells. My brain worked far better before college. You probably were wise to avoid it.
Here is a quote from the Physics of Woodwinds in Sci. Am 1960 - Arthur Benade:
“… not only do the side holes cut off the bore at a convenient spot for getting a scale; they also play a large role in setting the tone quality of the sound within the instrument. And when they are open, they influence the way in which this sound is ultimately radiated into the air for the listener to hear. A length of plastic tubing played with a clarinet mouthpiece gives a dull, plumbing kind of sound that few people can identify. When this same pipe is provided with a row of closed side-holes followed below by four or five open ones, the tone changes strikingly into the woody voice of a clarinet”
Benade elaborates (extensively) on this in Journal of the Acoustical society of America (1960) in an article titled “On the Mathematical Theory of Woodwind finger Holes”.
There’s also a fair bit on this in Fundamentals.
In a somewhat related article in the same journal the year before, “On Woodwind Instrument Bores”, Benade makes this interesting assertion: “On theoretical grounds at least, it would appear that an instrument less sensitive to wall material could hardly be found.” Benade is refering to woodwinds.
