Author: vboboe
Date: 2008-09-01 20:48
jhoyla, thanks for your thoughtful answers, and clarifying the function of the midline bundle of continuous long fibres
Your Q & A follows
Q <<I admit to a lot of confusion regarding your terms; I am not sure why, when you take the side measurement down to 64, that this somehow takes the "peak too close to the tip edge" - logically speaking, if the sides of my inverted chevron are at 64, the "peak" of the chevron will be commensurately lower, and my overall tip length so much greater>>
OK (2) answers to this
A1. If one draws diagrams on paper with ruler & sharp pencil (perhaps raising the measurement scale ratio 3:1 for easier-to-see results) and if one measures cross-bucks 64-70, 65-70 and 66-70 (or indeed, the same using 72 as the consistent measurement) it's clearly demonstrated that the peak of the apex *rises higher* when the sides are measured shorter (64) and vice versa = the higher the peak, the less distance there is between 70 clipped tip edge and the woodier midline blend in the tip
A2. On the other hand, if one is unconsciously competant and automatically positions the knife at the same diagonal angle either direction irrespective of the short, medium or long measurement on the sides, then the apex will be the same type of triangle each time -- try drawing that on paper using a protractor to mark the same angle for the diagonal line from 64, 65 & 66 -- and yes, the length of the tip gets longer for each mm further down the sides in this case
However, digest these concepts with clipping the tip back -- longer thinned tips end up quite raucous, whereas all we need for responsive playing is rowdy -- however, since we usually clip off the fold at 72, and since we always hope that we won't need to clip the tip any shorter than 70, it makes sense to proportion the length of the tip so it's raucous at 72 and when clipped to finished playing length is tamed nicely to rowdy
-- personally i hope that's 71.5 mm with a nice long flexible area 3-4mm between tip edge and mid-line wood, but that standard of excellence has not yet arrived in my knife hand's tip-thinning skills (which is why i'm favoring a file at the moment)
Q. <<you do not mention the steepness of the slope from the heart down to the inner tip; I think this has even more of an effect on the overall performance of the reed than the chevron-angle subtended at the peak. And is this slope shallower at the peak, steeper at the sides? Or the opposite?>>
A. this is a very interesting question, and i'm going to analyse it as an isolated feature (!) some more so i can mentally visualise the topographical contours of reed-geography in microcosm before being able to answer it with any intuitive comprehension
Q. <<How deep and broad are your windows?>>
A. This is a bit confusing, since i end up with 3 pairs of windows, but assuming we're only discussing the most important heart windows
Depth -- only down the cane layers as deep into the mid-bark as necessary to stabilize the C tone in the heart
Broad -- my heart windows are W shaped, although often the W ends up knifed so the W looking more like 2 U's rather than 2 V's, so this means my heart windows are not much narrower at the bridge above the catch than they are wide at the blend
Q. <<How thick is the spine?>>
A. Again assuming we're only discussing the portion of spine in the heart, i usually aim to debark it as a result of shaving the heart windows, and i usually shave off the shiny bark on the rails in the heart section the same amount, to approximate the same height of heart midridge and rail ridges -- leaving bark on in the heart anywhere is too stiff for me
In the back, the spine isn't debarked at all, so it's as thick as the original GSF cane piece gouge made it. I usually try to keep the shiny bark spine about 2mm wide down centre of the back (ha! says my knife hand)
Yours thoughts re << a reed's job...>> and your 7 points, agreed in general principle with the following Q's raised ...
Point 6 needs a bit of clarifying, is your <<fundamental note>> the holy grail of C octaves blown on the reed itself, or some other fundamental?
Point 7 is puzzling -- on my reeds the back windows are usually shaved only as deep as the top layer of the mid bark, and are usually started as strips 2mm across, and can be 3mm+ wide when reed is finished -- this gives me a tone in the back that is considerably higher pitched than C but not as high as an octave above C, so i can't figure out why you think the back <<reduces high-frequency overtones>> ?
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