Posted on August 23, 2019May 23, 2025 by Dale Phillips Intonation in the Real World Intonation in the Real World by Mike Doolin from his 2006 GAL Convention lecture previously published in American Lutherie #92, 2007 Getting guitars to play in tune has been a major topic of interest for many years, both for guitar players and guitar makers, and it has been a major source of frustration as well. During our current “Golden Age of Lutherie” the bar has been raised for standards of craft, playability, and tonal quality, as players have become more sophisticated in their expectations and builders have become better educated and more demanding of their own work. Expectations for accurate intonation have come along with all that: it’s no longer acceptable for a guitar to only play in tune for the first five frets, or in a few keys. Modern players are using the whole neck, exploring extended harmonies, and playing in ensembles with other instruments. They are looking for instruments that play in tune with themselves and with the rest of the musical world. It turns out that guitar intonation is a huge can of worms, because it is really two topics: ▶ What does it mean to be “in tune?” ▶ How do I make a guitar do that? Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on July 31, 2019May 23, 2025 by S Mc Herr Helmholtz’ Tube Herr Helmholtz’ Tube by Mike Doolin previously published in American Lutherie #91, 2007 See also, “There’s a Hole in the Bucket” by Cyndy Burton “Sideways” by John Monteleone “Three Holes are Better than One” by Robert Ruck Design innovator Mike Doolin tried an interesting experiment. Mike’s guitars have the distinctive double-cutaway feature and they don’t lend themselves to a port up in the neck/cutaway region for reasons of underlying structure. So Mike put one in the lower bout and very unexpectedly found his Helmholtz resonance had raised something like a major third. He felt that compromised the responses of the guitar. His solution was to “tube it.” The side was ported before I assembled the guitar. After gluing the back on, I realized the change in the Helmholtz when I tapped on the guitar with the port open. It seemed obvious that a shift of a major third up was going to radically change the sound of the guitar, probably killing most of the bass response. I knew that ports in bass reflex speakers are often tubes, where the longer the tube the lower the resonant frequency. I also knew that the tube could be either inside or outside the box. So I initially held a roll of toilet paper against the port, letting the cardboard core of the roll form a tube that extended the port. That dropped the main air resonance back down, showing me that I was on the right track. Then I turned a tube of wood on my lathe to fit the hole and experimented with the length until the air resonance moved less than a half-step with the port closed or open. I recall the port being 1 1/4" in diameter and the tube being about 2 1/4" long, but that’s just from memory. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on January 19, 2010September 9, 2025 by Dale Phillips Questions: String Compensation Questions: String Compensation by Mike Doolin Originally published in American Lutherie #69, 2002 and Big Red Book of American Lutherie Volume Six, 2013 Brett from cyberspace asks: I had always been of the opinion that saddle compensation was to overcome the tendency of a thicker string to be less amenable to vibrate than a thin one. So a high E will be vibrating close to the saddle, and a low E, being stiffer, will start vibrating a bit further away, hence compensation. That idea gave me peace for a while because I really couldn’t see the tiny distance a string gets pushed down to the fret as making any significant difference. The kicker, though, is that if I believe that theory, the string isn’t vibrating at all where it touches the saddle. If that’s the case, how does the vibration actually travel to the body and neck? If I follow my logic further, I’ve got to concede that the vibration is a type of compressive function in which the string compresses the axe as it gets to the widest part of its travel, lets it off as it passes through the resting point, and compresses it again as it zooms out to the widest point of its vibration on the other side, with maybe a slight forward bending of the guitar at the tightest points of the vibration (because the string isn’t lying flat on the fretboard). If a vibrating string’s tension isn’t constant, won’t a strongly-picked string tend to be sharp? Further, won’t it tend to go sharp-flat-sharp as it vibrates in decreasing cycles as it runs out of energy? It’s nano stuff I know, but I’ve always wondered. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
