The Art of Tap Tuning Virtual content
Additional tunings, (Appendix C, Pg. 37) The Art of Tap Tuning provides recommended tunings for 12 acoustic string instruments including: ukulele, F4 mandolin, A5 mandolin, F5 mandolin, H5 mandola, violin (mezzo), D18 guitar (standard X-bracing), classical guitar (fan bracing), jazz guitar (longitudinal bracing), tube-and-plate banjo (flattop and arch top tone chambers), one-piece flange banjos (flattop and arch top tone chambers), and bass viol (contra). This web page will provide tunings for other instruments as they are added to our list. Please do not hesitate to email your findings to me at siminoff@siminoff.net.
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StroboSoft's "Spectrum Window" (DVD): In the DVD's discussion of Peterson's StroboSoft® I incorrectly said that the frequency range of the "spectum window is settable to other ranges." It only has one setting, 0Hz to 5000KHz, which is ample to cover the range of the standard eight musical octaves.
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Selecting a Tuner, (Chapter 4, Preparation for Tuining): Some questions have arisen about using a guitar tuner for tap tuning. While some analog tuner/compressor combinations may function well, many guitar tuners are limited to only E, B, G, D, A. This Boss® tuner provides the eight whole notes, plus a sharped note indicator. (However, I still recommend a strobe-type tuner for a front-end tuning device.)
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Clip-on Microphone, (Chapter 4, Preparation of Tuning): I have received some questions about using a clip-on microphone. In my testing, I have not found clip-on mics to be successful and I attribute this mainly to these microphones being so sensitive that they are overdriven by the initial attack of the hammer. Further, I have not found an ideal mounting place for either soundboard, backboard, or aperture tuning. I'm not suggesting that they shouldn't be used, just that further testing is warranted.
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Exciting a clean fundamental from graduated soundboards and backboards, (additional comment to Chapter 5, Tuning and Voicing): Generally speaking, a soundboard or backboard that has been graduated evenly in concentric steps from its thickest to its thinnest regions around the entire board will produce a tone consisting of a more prominent, well-defined fundamental. On mechanical strobetuners (those with spinning wheels) this will result in a clearer, more prominent image of the fundamental (See Fig. 4.10). During the tuning process, take measurements at various points around the concentric areas to ensure consistency of graduation. (Diagram at right shows example of measuring points for F5 mandolin backboard.)
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Some helpful tips from a reader: Luthier Ken Jewell shared these interesting observations:
1) When using StroboSoft's spectrum screen, expanding the window as large as possible makes it easier to pick out specific frequencies.
2) When tapping the tone bars or backboard, tapping lightly produces a clearer reading on StroboSoft. [Siminoff note: This holds true when using other types of tuners as well as StroboSoft. The harder you tap, the more of the overtone series you excite.]
3) I first started using the Sony Stereo Digital mike and it wasn't a good choice. It appears to pick up a lot of extraneous noises. I found the uni-directional Shure SM57 to work the best.
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Tuning a guitar bridgeplate: The text does not mention how to tune a bridgeplate or whether it is even necessary. You don't actually "tune" the bridgeplate; consider it to be part of the soundboard. While it's mass (weight and size) do affect the tuning of the soundboard, the actual tuning will come from adjusting the soundboard' braces and tone bars. However, do consider that the heavier the bridgeplate is, the higher the resonant frequency of the soundboard will be. Conversely, the lighter the bridgeplate is, the lower the resonant frequency will be.
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Which octave?: A few questions have come up regarding which octave to shoot for when tuning soundboards and backboard. I purposely did not include recommended octaves in the text because you can waste a great deal of time trying to chase octaves. Unless you have constructed a soundboard or backboard that is ridiculously too thick or too thin, you can only end up in at the correct octave. The problem centers around the fact that when you excite a soundboard or backboard, you also generate the note of the second partial (the octave of the fundamental) and according to how you hit the soundboard the amplitude of the second partial can be significant. (Note the tests of the tuning fork in the StroboSoft demonstration on the DVD where the second partial [the harmonic] was substantial.) Aim for the note - you'll end up in the right octave.
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StroboSoft gets a facelist - and new features (12/07): The latest version of StroboSoft Deluxe (v2) was released in December 2007 and features special settings for doing tap tuning. In the tap tuning mode, the system locks on the tapped note and displays it on the screen. The result stays on the screen until the next tap is done. A tap tune threshold setting enables trimming the lowest and highest intensities within which the tapped note should fall. The new version of StroboSoft Deluxe no longer requires the use of a compressor. Click here for more information about StroboSoft Deluxe v2.
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What to do for instruments not listed: I've had many requests regarding how to find "target tunings" for instrument designs not listed in the book. The answer is really quite simple. You can develop your own beginning "target tunings" by building an instrument as you normally would and then measuring the tunings of the instrument's braces, tone bars, plates, and air chambers. Then begin to tune each part to the nearest note that is neither sharp nor flat. For example: if you have that a brace or tone bar is E329.63+20c (fourth octave E that is 20 cents sharp), then remove wood until the bar is a true E329.63 - and is zero cents sharp or flat. This is the basic premise of tap tuning. Then, when you have the instrument constructed, you will have a set of "target tunings" for how you built that instrument. You can use this information to make decisions on either replicating that identical construction - and resultant timbre - in future instruments, or make a change with knowledge and data of what the change is you are making.
The only decision you have to make is what concert pitch to use. You have two choices: 1) you can use today's concert pitch of A440, or 2) tune the parts a quarter-tone off using concert pitch A431? Concert pitch A431 is what was popular during the period Loar was recommending tunings for Master Model instruments at Gibson. And, it just so happens that A431 is a quartertone off; that is A431 is halfway between A440 and G#415, musically speaking. It is very much a coincidence that this quartertone tuning is what contributes to making these instruments sound so wonderful today when the strings are tuned to concert pitch of A440 and the parts of the instrument are tuned to concert pitch of A431.
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"What do I do once I have target tunings?": This is a question that often grows out of the previous topic of "What to do for instruments not listed:" Let's assume you've built an instrument, you have the "target tunings," and you want to build your next one so it has a bit more bass response. The answer is pretty simple: If you lower the tunings of the parts, you will improve the instrument's bass response. If you raise the tunings of the parts, you will improve the instrument's treble response. Or you can try to do both. For example: you have target tunings from your last instrument and would like to get a bit more bass response as well as a bit more clarity in the upper registers. Simple: lower the tuning of the air chamber (either make it larger or reduce the size of the apertures) and make the next set of braces so they tune a half step higher. And, hopefully, you can imagine the other scenarios.
Generally speaking, lowering the resonant frequency of the parts improves bass response and adds warmth and fullness. Raising the resonant frequency of the parts improves the treble response and adds clarity and brightness. Since you have the ability to tune the backboard, soundboard, and air chamber, you can consider the contributions of each of these to the whole sound.
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© Copyright 2008, Roger H. Siminoff, Arroyo Grande, CA USA.