Two years ago at NAMM, I heard Buzz Feiten playing in one of the demo booths (the featured artist was a drummer, Buzz was a sideman). He was definitely a very talented guitarist.
I've participated in extended discussions on the Feiten intonation system on other message boards. Personally, I would put it in the snake oil catagory.
The system is patented and has two main components. The first is a displacement of the nut toward the bridge. When you press the string down at any fret, you aren't just stopping the string, you are displacing it downward as well. That has the effect of making the string a tiny bit shorter than it would be if you could stop it at the fret without pushing it down. That tiny error will cause the fretted note to play a tiny bit sharp relative to the tuned open string. So, the nut adjustment is compensating for that. This doesn't matter much on a bass or guitar that you play barre chords on, but the Feiten system is originally intended to improve the intonation of acoustic guitars where, in many styles, you would play with more open strings. As soon as you fret the string anywhere, the benefit of the nut change goes away, since you must cause the downward displacement to fret anywhere on the neck. A capo'ed guitar shouldn't exhibit this intonation problem and it should be less noticeable with a properly set zero fret.
The other part of the Feiten system is a set of modified intonation setups that try to improve the overall sound of chords that are commonly played on the guitar. Although you often get into a discussion of alternative tempering and favored keys here, this isn't really what Feiten is doing. When you set the intonation on your instrument now, what you're doing is compensating for the stiffness of the strings. A big fat, stiff string doesn't vibrate freely at it's ends and acts as if it's shorter than an ideal string. But the harmonics of this same big fat string are affected differently by the strings stiffness (higher harmonics are less encumbered by the stiffness). So, in a normal setup, you will tend to move the bridge piece away from the nut to make the fundamental's effective vibrating length longer and bring it into better tune with the harmonics. As you know, it really makes a difference because the string stiffness really causes non-ideal motion. The way intonation is normally set is to compare the 12th fret fundamental pitch (1 octave up from the open string) with the 12th fret harmonic and adjust until they match.
If you think about it, that makes the adjustment work great if you play at the 12th fret a lot, but for most of us you're playing well below that on the neck. And for that area, setting the intonation traditionally is way overcompensating relative to where you want it to be. So, that's the other part of the Feiten system - it's a set of offsets, specific for each string, that you set up to that should lead to better normal chord intonation. Again, if you play folk-style chords low on the neck, this should make a significant difference. When you play a solo high up on the neck, it matters less since you're playing single notes (or partial chords). If you were playing chords high on the neck, they actually may be less sonically pleasing that a traditional setup, but in that case, you wouldn't really want to be setting up with Feiten (it doesn't claim to fix everything).
The way that you actually do a Feiten intonation setup is that you tune the instrument to normal open pitches, but instead of adjusting the 12th fret harmonic to match the open (or 1st harmonic pitch), you adjust the string length per the Feiten adjustments, which generally are a little flat. It helps to have a (licensed, of course) electronic tuner to help you hit the targets.
Both these elements actually do make a lot of sense - it's not totally bull, although it also really doesn't matter to most players. And the system is licensed by a number of really elite luthiers like Tom Anderson and Mike Tobias. I don't know Tom Anderson, but I do know that Mike Tobias well enough to know that he's not paying anybody any money for nothing.
But there is a kind of bogus general flavor to the entire thing as well. The problem is that he's the system is a thinking man's solution to a complex problem that's hard to explain and difficult for most people to get their minds around. So, rather than try to talk about the real virtues of what they're doing, there's a lot of hand waving and mumbling. And, rather than actually figure out a mechanism for calculating what your targets are (which would NOT be patentable), the Feiten system calls out a specific set of intonation offsets and a specific nut displacement (which you can patent).
If you're enough of a gearhead to have gotten this far, then you immediately understand what the problem with the Feiten system is. Each string gauge, material, and design has different vibrating properties. You know this when you change string sets and have to reset your intonation. So, a standard set of offsets isn't really going to solve your problem - they are correct only for the exact guitar and strings that they were originally calculated for. Change anything, and you aren't really optimal anymore.
That said, if you earn your living between the 3rd and 9th fret, chances are a non-optimized Feiten setup may well be better than a standard setup.
This is kind of a financial thing. You can get a patent for the embodyment of an invention - in this case, you tweak intonation in a non-obvious way and get magically better results. In particular, if somebody copies your offsets without licensing your patent, you can go after them with the full force of the law. If Buzz had come up with at set of instructions about how to set up any specific guitar, he could get a copyright for the instructions, but there's no way he could sue a manufacturer who followed his instructions but didn't admit it.
So, the ultra gearheads who made it all to the end must be wondering if there's an open source solution to better intonation. And I believe that there is one that's pretty darn simple. You know that traditional intonation setup optimizes intonation in the middle of the neck. To get a perfect, optimized setup, what you want to do is set up your intonation in the area that you *actually* play in. For example, if you normally play around the 5th fret area, then your intonation procedure would be to tune the 5th fret harmonic (2 octaves up from the open string) is perfectly in tune, then adjust the bridge/string length until the open string is also in tune, repeating it incrementally until they match. Now, the intonation of notes fingered around the 5th fret will be more true and you'll get the benefit of improved sound with exactly your strings and instrument.
If you plug your traditionally-intonated instrument with fairly fresh strings into your tuner right now, hopefully you'll see that the open string and 12th harmonic match pitch. Now, play the 5th fret harmonic. Off by a couple of cents, right? And that's right where you play! This is the main problem that Feiten is trying to deal with.
If you play a lot of open chords, then there's no way to do the equivalent of the adjusted nut other than to have very low action across your neck. But again, the amount of nut shift really is dependent on the specifics of your equipment, not a fixed, cast-in-concrete shift per the Feiten system. I think this effect is fairly minor compared to the intonation adjustment.
Try it the next time you have some time. I'm not a good enough guitarist to notice the difference, but I am a good enough techie to crack the puzzle!
David Fung
