OK, so I just thought about this. Ya know the resonator on most bass drones you see? The one that looks like a big ivory/wood/whatever donught?? Well, all the ones I’ve seen just have the little hole in the center connecting to the little hole from the drone pipe. I’m curious to know if this really does anything to resonate??
I would think that if you hollowed out the disk, you’d get a deeper more mellow tone than keeping most of it solid…kinda like those punk kids who all drive around now with their “turbo mufflers” on their cars. Bigger volume (of air) seems to equal bigger volume of sound. Am I off base here???
Most (all?) drones of any type have a hollow space at the exit. As the drone size increases, the size of the resonance chamber needs to increase as well, so on something the size of a bass drone, it’s gonna be big, hence the doughnut.
A fair number of wind instruments have this wind chamber in them - bassoons, etc.
Well, there are different schools of thought on this subject. My experience has been that most of the older sets that had the “puck” or donut, were NOT hollow. Without the hollow aspect to them they most certainly would NOT be a resonator, it has been postulated that the “puck” was added to direct the sound of the bass drone either outwards to the audience or up to the piper. ???
When a bass drone resonator is indeed, hollow, the tonal qualities are indeed changed. It is measureable by both the ear and more scientific instruments. The sound gains a certain “roundness” or depth to it. For example, sort make a tight channel with your mouth..jaw almost closed..teeth close together..keep your lip opening about the size of a penny (or briefly inserted finger) and say “ooooo”..now..still making that same sound or “note” lower your jaw, thus creating a larger chamber..you should notice a marked change (without changing the pitch)
..just don’t let your family catch you doing this..they will think your off your rocker…
I wouldn’t have asked if they were hollow already. Every one I’ve seen to date was most definitely SOLID in it’s construction - hence the original question.
Brian, the Childress halfset I recently sold was constructed of brass sheet and tubing. It is soldered/braised together but hollow inside. The set I have now (also by Childress) is plated (chrome or nickle) of similar construction and the face is of animal antler that fits into the cup to complete the resonator… Also hollow construction.
The other sets I have are straight bass drones with a hole through the end of the mount.
I’ll post a picture if you want to see the construction as I can remove the cover of the resonator without damaging it.
Hollow… not long ago someone mentioned it was a place to stash your weed when travelling. I have no experience in that area.
i have only seen photos, but i made mine from brass with wooden “plates” on either side and it is hollow. maybe i was just lucky, but it really sounds good to the point that i wouldnae be happy without it.
it added a mellow hollowness that wasnae there before.
the wood i used was cut from a 1000+ year old cypress tree that was probably cut in the '30’s and sunk in pensascola bay. it is of sound board quality, though i don’t think it makes all that much difference, probably any hard wood would work
I have seen both kind. Solid and hollow. You’re exactly right. The hollow types do resonate the sound more loudly and perhaps richly. [But that’s subjective. the set, materials, reed etc. all play in here] The sound difference is akin to smacking a drum (hollow ) vs. smacking a tree stump. (not hollow )
Sound resonates best through a hollow vessel. Its why all the best tenors chould probably fit a billiard ball in their mouths.
Best regards,
Scott McCallister
(Note: The author of this post does not endorse the smacking of tree stumps nor the eating of billiard balls)
I have seen old sets with either hollow pucks or blind bored pucks, (without a hollow). The 180 degree bend ending with a puck or trumpet termination makes it easier for the player to reach the drone start or stop the drone with a touch of a finger. The amount of hollowing, or lack thereof, makes a tonal difference, which can be heard by experimenting.
Much experimentation has been done the last few years by some of the makers, to achieve the tone they are after. You may note a resonator in the baritone drone as well, and often the lack of one in the tenor.
The orignial question put forward a couple of thoughts about what the resonator is doing and how it is changing the sound. Here are some bits of information about resonance in a chamber. I would like to mention that these ntoes are made without any knowledge to pipemaking (or playing). I am very very new to pipes in the sense that I don’t even have a set…yet! I have been listening to them for many years (Seamus Ennis in the CD Player right now), and I am a musician. My profession features the development of products that use a lot of acoustic chambers.
Any chamber that is injected with acoustic energy has two parameters that directly correlate to the chamber’s effect on the sound. One is the volume of air in the chamber, the other is the tuning of the port. The port is the air exit of the chamber and it’s tuning is an acoustical representation of the area of the port and the depth of the port. In terms of bass drone resonators, this corresponds to the diameter of the hole, and the thickness of the material in which the hole is cut, akin to “Chimney height” in chanter finger holes.
Typically an acoustic resonance chamber is large and does most of it’s work for lower frequencies. A chmber makes certain frequencies (usually a small range of frequencies, rather than a single note) more effecient. It technically doesn’t make it louder. When acoustic energy goes from any pressurized area to free air, it loses a lot of it’s amplitude. The resonator allows certain frequencies to lose less energy, thus seeming louder. The most interesting part, is that a typical resonator on a bass drone is way to small to be effective on the fundamental note, or even the second harmonic (73hz and 146Hz on concert set). The resonator would be accentuating maybe the 4th 5th and 6th harmonics. The effect of this is that the sound gets much thicker, having a broader spectral output. The other side effect is that making the resonator larger or changing the material (material would effect overall efficiency) doesn’t have a huge effect on the fundamental, but might color the sound of the drone as a result of slightly different upper harmonics. One would have to make it quite larger than useful do do anything more than color the sound a bit.
The port tuning of the resonator on an Uilleann bass drone by the way, is actually useless. The port length is insignificant in dimension to effect any audible frequency. For bass drones designed without a resonator, they still sound plenty rich and thick, because they have a flareout of the bore at the end, as do so many wind insturments. This ‘horn’ again helps effeciency by allowing the change from pressurized air to free air to be more gradual.
Of course, a resonator would have to be hollow for any of the above to pertain.
An interesting acoustical analysis. My approach, as are most pipemakers, is strictly pragmatic. See what has been done in the past and copy that. Try various combinations and LISTEN carefully to the results these changes make, then settle on designs that give the most aurally pleasing results. Small, theoretically unimportant changes, can result in obvious differences. As in any musical instrument, the difference between a good sounding set and a great one are due to these differences and the attention to detail and careful aural analysis by the makers and players with trained ears. Many times these design improvements are the result of serendipity or happy accidents which get incorporated into future sets as the makers mature in their craft.
Very interesting contribution, Tumbleweed. So, if I read you right, you implicitly confirm my original naive assumption that the soundbox on the end of the bass drone mainly serves to direct the sound towards the audience and/or musician. I have seen some boxes are made of brass that are big and hollow, and they seem (entirely subjective impression) to bring out the bass drone, but it may just be that that’s the way the drone has been reeded.
One of the gratifying developments of the last few decades has been the development or rediscovery of pipemaking knowledge which was so tacit that people didn’t even know it existed, or realise how much the beast is amenable to rational analysis. I don’t want to malign anyone, but I suspect that quite a few of the handful of still practising makers say circa 1970s were mainly trying to make copies of older pipes which were as faithful as possible. Uilleann pipes were so isolated from the rest of the world that they were revered but not understood, like a mystery of religion, and many people didn’t really grasp the fact that objective and empirical knowledge can be applied to them, including that possessed by makers of other woodwind instruments.
Yes, the resonator will contribute to directing sound. Another quick technical note… lower frequencies become harder to direct. As frequency gets higher, it is more directinal and begins to behave more like light. Since the effects of the resonator are directly applied to the higher frequency harmonics of the drone, the direction it points becomes important. The same would be true with a bell design. Point it up or out, and those around the piper will hear it better, point it down, and quite a bit can be lost.
To touch on Ted’s points as well, the audio arts (whether applied to musical instruments or reproduction of audio) are a strange mix of art and science. The differences between one resonator design and another may be very slight, and applied to a “non-major” part of the drones character, but in the hands of an artisan, these differences are everything. Understanding the science is beneficial, but having the gift of the art is what 13 year waiting lists are about. And if you can’t make a decent bass drone or a decent reed for it, your resonator is not going to save you.
Tumbleweed
(very excited – pre-newbie piper that I am – that I can contribute something to the forum)
I don’t make pipes. Much of my info. comes from conversations with Benedict Koehler and David Quinn, Geoff Wooff and others, as well as observations of a number of old and new sets. I know K&Q use different designs for bass drone resonators, depending on the pitch. Typically the baritone drone will have a resonator and the tenor may not. The tenor without a resonator will have more “bite” or “edge” to the tone. A larger variable is the reed. Balance between the drones is largely influenced by the reeds. I feel cane produces the best sound but they require fiddling and futzing as well as a break-in period. Once set up, they can last for years. Composites can be less trouble to set up and also be more stable while playing the upper register. The tone can be quite good with some composites and poorer with some other designs. I am working on an article on cane reed construction based on a visit with launeddas makers in Sardinia. They use a unique approach to single beating reeds that yields the most stable and best sound I have encountered.
Certainly the science of acoustics is applied by some makers, and I know makers who have had exchanges with oboe and other reed instrument and reed makers as well. Geoff Wooff certainly has learned a great deal by carefull and painstaking analysis of the old master UP makers, as have K&Q. It is the blending of science with the art of making, coupled with a good ear and lots of research and experimentation that are now yielding good results by modern makers. Science alone won’t do it. There is no substitute for a good ear, as I was told by the man who voices $4,000 Loree oboes. There are those who do far less of this and the sound of their pipes show it. Someone said that most makers produce a recognizeable sound from their sets. You must judge for yourself which ones sound best to you. Until just the last couple of years, Liam O’Flynn did not like any of the modern stuff. I hear he is changing his opinion of late. The pros can be rightfully very pickey about tone, tuning and playability. Some modern makers are beginning to satisfy them. The standards of pipe making are continually rising, to all our benefit. Now if the waiting lists were just shorter or existant…
) vs. smacking a tree stump. (not hollow 
)