List, I thought I was sending this to the list but I noticed that it went to Richard Brekne only. Therefore I am forwarding this to list. Forgive the funny formatting (if any - it looks funny on my screen). Phil Ford On Sun, 17 Nov 2002 20:53:19 +0100 Richard Brekne <Richard.Brekne@grieg.uib.no> wrote: > Hi Phil, there are a couple points I seem a bit > unclear on below. > > Phillip Ford wrote: > > > > > 2. CFT seems pretty clear that he intends > the rear duplex to deal with > > longitudinal vibrations.... > I'm not really sure I see the correlation here. The correlation between what and what? > I read the idea that "the back > length is to be some multiple of 1/2 the > speaking length" as something one > arrived at empirically. That at the same time > this results in this length being a > harmonic relative to transverse vibrations is > coincidental to the desired effect > on longitudinals. Which I thought was my point. The length of the rear duplex resulting in a transverse vibration that is a harmonic of the speaking length is coincidental and not claimed or given as a reason for the invention in the patent. Yet some (or one) are now using this patent as a justification for the need or efficacy of this very thing - tuning of transverse vibrations of the rear duplex. > > > > > 4. Assuming that you could tune this portion > of the string for longitudinal > > vibration, how do you go about tuning > something that only your dog can hear? > > And, assuming that we now have machines that > could hear this for us, how did > > they go about doing this back in CFT's day? > > Low enough in the scale you can certainly hear > the longitudinals. But the duplexes are not used low in the scale. > I suppose if one > found certain modifications have certain > affects down there one could extrapolate > that these same results would be applicable > over the rest of the scale. Agreed. But how to go about locating the aliquots high in the scale? Since you can't do it by listening you have to do it by measuring or comparisons to locations lower in the scale. This is not 'tuning' the aliquots. > Further > the "whilstling" sound that is supposed to be a > result of an inappropriate > configuration is certainly hearable, and > certainly responds to variations in > duplex lengths, and for that matter the > condition of the termination. Whether this > is indeed has anything to do with longitudinal > frequencies is another matter. > > -- > Richard Brekne > And whether the sounds that result from one particular location of the aliquots is better than with another position of the aliquots, regardless of the type of vibration that is causing that sound, is another matter. Phil F
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