The resonance behavior of the neck may be as or more important than its mass. If the neck is resonating in the frequency range of the music you are playing, it is sucking up some of the energy you are putting into the strings and dissipating that as internal heating rather than as sound, because of its relatively low surface area. If the neck is relatively heavy and is not resonating, it can act as an anchor for the body and soundboard to push off of so they achieve maximum displacement and efficient transduction of the string energy into sound in the air. The worst case would be when the neck has resonant frequencies in the musical range and is relatively light, so that motion is easily transmitted to it from the strings and the body and soundboard of the instrument â then lots of your plucking energy gets diverted.
A physicist or engineer can assure you that almost any object has a fundamental resonant frequency, normally with a number of harmonics in addition. The resonance frequency depends on the size, shape, mass density, and stiffness (modulus of elasticity) of the object, and can be altered by changing the tension or compression force on the object. How can you determine the resonant frequency/ies of your neck, since it is too complex an object to calculate them easily as you can with a taught string or the air column in an organ pipe? I suggest using Chladni patterns, the way luthiers sometimes do when tweaking soundboards. You will need a variable frequency sine wave generator, an amplifier, an audio speaker and some fine sawdust or powdered laundry detergent. Observing Chladni patterns requires a smooth, horizontal flat surface on the object, and on a theorbo neck, that may be only the fingerboard, so slide all the tied frets up to the nut (You do have marks to indicate t! he correct locations, donât you?), lay the instrument on its back (preferably on a dropcloth to aid cleanup) supported on cushions or rolled towels with the fingerboard horizontal (use a small carpenterâs level if you have one). Sprinkle the fingerboard sort of evenly with the powder and set the speaker near the instrument. Sweep slowly through the audio frequencies with your sine wave audio driving the speaker. If/when the neck is resonating at a given frequency, the powder should tend to gather at the nodes, while clearing away from the antinodes. If your fingerboard is cambered, sorry, this may not work because of the lack of a flat surface. Another method commonly used for observing resonance behavior is to illuminate the object in question with a strobe light of variable frequency in a dark or dimly lit location, again while driving the object with a sine wave of audible frequency. Unfortunately, in this case, I suspect the physical motion of the instrument neck will be too small to be observable by eye, so it will not work. Regards, Daniel Heiman Sent from Mail for Windows 10 From: Roman Turovsky Sent: Thursday, March 28, 2019 10:45 AM To: Luca Manassero Cc: lute Subject: [LUTE] Re: Heavy theorbo neck Virtus stat in medio. RT On 3/28/2019 9:37 AM, Luca Manassero wrote: > Dear all, > thank you for all your interesting suggestions! > I'll probably think again about it ;-) > All the best, > Luca > ---- On dom, 24 mar 2019 05:10:08 +0100 Howard > Posner<howardpos...@ca.rr.com> wrote ---- > > I'd have asked him the question I asked you. > Sent from my iPhone > > On Mar 23, 2019, at 18:02, Roman Turovsky <[1]r.turov...@gmail.com> > wrote: > > > > Pat's opinion re the luthier's fault. > > RT > > > >> On 3/23/2019 7:01 PM, howard posner wrote: > >> What do you base that conclusion on? > >> Did the lute formerly have a lighter neck? > >> > >>> On Mar 23, 2019, at 3:16 PM, [2]r.turov...@gmail.com wrote: > >>> > >>> One of my lutes is neck-heavy, and it definitely has been > detrimental to its sound. > >>> RT > >>> > >>> ==== > >>> [3]http://turovsky.org > >>> Feci quod potui. Faciant meliora potentes. > >>> > >>>> On Mar 23, 2019, at 5:48 PM, [4]yuval.dvo...@posteo.de wrote: > >>>> > >>>> My lute builder, Dieter Schossig, is actually a physicist, and he > also told me about this. It's about the energy that gets lost in the > neck, instead of reinforcing the sound. > >>>> > >>>> Am 23.03.2019 22:29 schrieb John Mardinly: > >>>>> Some guitar makers have also believed that neck stiffness > improves the > >>>>> sound. Ramirez 1A guitars have a significant graphite-epoxy inset > along > >>>>> the neck to stiffen it, and that is said to be significant in a > neck > >>>>> that is only 66.7cm. > >>>>> A. John Mardinly, Ph.D., P.E. > >>>>> On Mar 23, 2019, at 2:22 PM, howard posner > <[1][5]howardpos...@ca.rr.com> > >>>>> wrote: > >>>>> On Mar 23, 2019, at 5:43 AM, Luca Manassero > <[2][6]l...@manassero.net> > >>>>> wrote: > >>>>> Iâââ¬ÃÅm about to ask him to rebuild the long neck of my > big > Hasenfuss > >>>>> theorbo, as the instrument has a fantastic voice, but Hasenfuss > >>>>> built a > >>>>> very heavy long neck, so it is really painful to homd during > >>>>> concerts. > >>>>> A lighter neck should solve the issue. > >>>>> All the best, > >>>>> Luca > >>>>> Consider that the heavy neck may be part of what makes the > fantastic > >>>>> voice. I've been told that a neck that's heavy, and therefore > does not > >>>>> vibrate, increases resonance because a vibrating neck has a > damping > >>>>> effect on the body of the instrument. I don't recall whether > Hendrik > >>>>> told me that, or it was volunteered by someone else, and I can't > vouch > >>>>> for its accuracy as a matter of acoustical science. > >>>>> But I can tell you that the heavy neck on my Hasenfuss theorbo > was > >>>>> never a problem because I never held the instrument while I > played it. > >>>>> I just used a strap, and ran a leather or fake-leather bootlace > from > >>>>> the bridge-end of the instrument and sat on it (the lace, NOT the > >>>>> instrument). I could take my hands off the theorbo completely. > >>>>> Indeed, listeners may have preferred it when I did. > >>>>> And it's a lot cheaper than rebuilding the neck. > >>>>> H > >> > >> > >> > >> To get on or off this list see list information at > >> [7]http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html > > -- > > References > > 1. mailto:r.turov...@gmail.com > 2. mailto:r.turov...@gmail.com > 3. http://turovsky.org/ > 4. mailto:yuval.dvo...@posteo.de > 5. mailto:howardpos...@ca.rr.com > 6. mailto:l...@manassero.net > 7. http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html > --
