Saabfender-Thank you for taking my post in the spirit in which it was intended. Guys like you and Jim C are why I did it. You took the idea,modified it and made it work for you. That's all I wanted out of this. It's so simple,cheap,quick, easy to do,and completely reversible that I don't understand the reluctance to try it, but with your success perhaps others will.
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Forget Fatfinger I found the deadspot fix!
- Thread starter Fullerton50sFan
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- dead spot fix
It seems wrong to get grief when you’ve got an idea to share. While skepticism is a useful intellectual response, it easily turns into laziness when it’s used to quash idea rather testing it for veracity.
Testing it is the responsibility of the recipient of the idea, not its author.
“Hey, I just wrote a cool song.”
“Have you recorded it or performed it yet and has it sold a bunch of copies? If not, not interested. It’s the only way I can tell a good song from a bad one.”
Testing it is the responsibility of the recipient of the idea, not its author.
“Hey, I just wrote a cool song.”
“Have you recorded it or performed it yet and has it sold a bunch of copies? If not, not interested. It’s the only way I can tell a good song from a bad one.”
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I completely agree.
It would be very simple to head to GC, find a Fender or two with a dead spot, and test it out. Adding a rubber washer or two to the string tree is quick and non-destructive.
- John
Micguy- You seem to be one of the few on here who has schooling in acoustic physics,but even you seem to ignore my insistence that a dead spot involves partial phase cancellation. I offer proof from a company called
ProSig,who are involved in the measurement,analysis, and solutions for vibration issues within systems,with clients such as NASA and British Aerospace. From their ProSig Noise and Vibration Blog, solutions engineer
James Wren's post "What is Resonance? Part 2"
"The resonance occurs when the maximum potential energy is converted
to the maximum kinetic energy,that is the input and the output are opposites at a particular frequency.
AT A RESONANCE THE PHASE WILL SHIFT 180 DEGREES. The center
(AT 90 DEGREES) will enable you to find the frequency of the resonance.
The phase is the relationship between the input and the output. When they are opposites you have a resonance. AT RESONANCE THE FORCE AND RESPONSE ARE 90 DEGREES OUT OF PHASE. Above resonance they are 180
degrees out of phase. If we assume a simple system,like a simple beam,
then at frequencies below resonance the force and response are in phase.
Looking forward to your response.
Dead spots on necks are, depending on how you want to think of things, not all that simple. A neck, if you excite it by attaching something to apply force, will resonate at a bunch of different frequencies, and in a bunch of different geometric fashions - there are bending modes (mostly what we're interested in here), torsional modes (which might play into dead spots, I'm not entirely certain about that), and modes from compressional waves in 3 axes, which probably don't affect us much in the bass world as far as necks go, but the "zing" on new round wounds probably involves some of those.
OK, so you have a bunch of different resonances, at a bunch of different frequencies. If you look at how they move, there end up being "standing waves" if you let the resonance settle from the initial excitation. A standing wave means there are places that are moving, and places that aren't moving. In the lowest frequency vibrational mode, if that is happening all by itself, the body is relatively stationary, the end of the neck is moving back and forth along with the whole rest of the neck, but the end is moving the most. That mode is usually low enough in frequency, and the most motion is at a place where strings aren't attached (the very end of the neck) that we don't typically encounter it - Fenders don't tend to have issues with that mode, but there are some headless basses, and a few basses with 2 + 2 headstocks, where if you have light enough tuners on them, the open A string or a nearby note will be a dead spot. I have a bass tuned in D standard (the "A" string on that is actually tuned to G) where I had to put heavier tuners on it to tame the dead spot at the end of the neck.
The dead spot we talk about a lot is a different mode - in that one, the neck is not all moving one direction, the end of the neck is moving one way, there's a point in the middle where the thing is sitting still, and then a section that's moving the other way. Again, the body is relatively stable (it's so much heavier than anything else in the system, so it tends to be relatively stationary). Anyway, when the placement of a fret and the tuning of a string at that fret corresponds with an antinode (a place that likes to move a lot in one of the vibrational modes), the string loses energy relatively fast - it's transferring its energy and feeding the vibration of the neck in doing so. In the case of my D tuned bass, it has no noticeable dead spot issues where we tend to look for dead spots - the D tuning means that the location of the fret where there might be a problem has moved, as it's 2 frets away from where it would be on a standard E tuned bass - that is enough in this case to make it practically immune to the dead spot typically in that area of the neck.
If you replace the string with a source of force at a fret location, where there is a dead spot, and look at the force and amplitude of neck motion, yes, there is a quadrature relationship (90 degree phase shift) between the forcing and the motion (amplitude in this case - the velocity and acceleration are all shifted from each other, so you have to specify what part of the motion you're talking about when you start to discuss phase shifts of things). We wouldn't call that phase cancellation, however - phase cancellation is used to describe systems where 2 things in antiphase (aka opposite polarity) tend to cancel one another - a humbucking pickup would be a good example of phase cancellation, where two hum signals cancel one another.
Extra credit for math wanna be geeks: Things in quadrature (a 90 degree phase shift) don't cancel, they add (but a bit funny) - if they're equal in magnitude, the result of adding 1 and 1 is not zero (which would be phase cancellation, or addition of two signals at 180 degree phase relationship) or 2 (which would be the result adding things in phase - or zero degrees phase relationship), its...the square root of 2. Those fluent in the Pythagorean theorem will understand this implicitly - a 90 degree phase shift means a right triangle, so you're calculating the hypotenuse of an equal legged right triangle. To add 2 equal things together and get less than one, you need a phase shift between 120 and 240 degrees - the closer you are to 180 degrees, the more they cancel.
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micguy-Thanks for your quick and detailed response, I am trying to learn. As I think I mentioned, my education was in film and television, I study physics as a hobby. I was a partner in a flight simulator business, so I studied aerodynamics to understand what we were simulating. I think flutter in flight control surfaces involves phase and resonance issues.
As a bass player, I have been plagued by the dead spot issue,
all three of my P basses had them, all at the anti-node 6th fret.
I thought the physics of it would be relatively simple, but I can see it isn't. I knew that 180 out is the sound of one hand clapping, Simon and Garfunkel. But is it possible that the improvement I got from the damping at the string tree is the interception of upper harmonics of the C# fundamental from the headstock,machine head,or the string tree in that 120-240 phase relationship?
Again,looking forward to your answer.
I would guess the improvement you heard from your damping disc was either a case of uncontrolled variables, or a case of confirmation bias (the experimenter wanting to hear a desired result).
I don’t have a good rational explaination as to how it would really do what you described. I am willing to be proven wrong, though - that’d mean I learned something, which ...I’m always up for.
I don’t have a good rational explaination as to how it would really do what you described. I am willing to be proven wrong, though - that’d mean I learned something, which ...I’m always up for.
And yet, in this day and age when it is so easy to do so, the OP still won't post up a photo of his amazing fix so that others can try and replicate it the same way he did it despite being asked numerous times over the last 10 days and 7 pages. No wonder that he's copping a bit of stick.
It ain't rocket science, you need to put some damping material (a rubber washer) between the strings and the string tree to damp any vibrations in the D and G strings between the nut, string tree, and tuner.Hmmmm... Just did a quick run through of this whole thread. Looks like the fender washer is still invisible.
How you do it is up to you, the OP made a larger oval hole in the washer (from my recollections, it's a while since I read post #1 and it is a bit long!) and slipped it over the top. You could remove the string tree, slip the washer over the parallel part and then replace the string tree.
I have a P clone where one of the string portions after the nut rings like crazy (acoustically), if you pluck an open D string then mute it there is a weird harmonic that rings for a few hundred milliseconds. As it is my home practice bass I have never bothered to do anything about it but might try a rubber washer under the string tree. I will report back if I ever get round to it.
Zombie thread, but I ran across it while being particularly irritated by the my dead C on the G string of my Squier fretless p. I dug through my junk box and found a rubber washer and put it between the tree and the D-G strings like the OP suggested. It made a pretty big difference. The note has much more resonance -- it doesn't thud and quickly die like it did. Dunno why.
Attachments
Has anyone ever thought of a more scientific approach to measuring dead spots and what affects them? Like a frequency analysis or a measurement of the output from the pickups? Surely we can audibly detect dead spots ... and we believe we can affect them. There has to be a measure that can be made to quantify that.
The whole discussion is based on an claim. it's not hard to test and see if it does fix a dead spot for any individual ... but I would be careful to claim it's a fix for dead spots. Too many unknowns.
The whole discussion is based on an claim. it's not hard to test and see if it does fix a dead spot for any individual ... but I would be careful to claim it's a fix for dead spots. Too many unknowns.
I wouldn't say this is a fix for every bass. I'd just throw it out as something that worked for me. Since these things are made of wood and have different densities and weights and such, nothing's going to work on every bass. I once changed the bridge pins on my acoustic from the stock plastic to ... mahogany? Some wood, anyway. All reports were that this would improve (treble, bass, sustain -- whatever I was looking for at the time). Wrong. The guitar sounded awful with those new pins. So someone might put this washer on their Squier fretless p and end up with some newer, more heinous dead spot. But it really took care of mine.
Also, my spot was at C, not C# as a lot of people have, so there's another difference.
Also, my spot was at C, not C# as a lot of people have, so there's another difference.
I'm confused by your picture, as it looks like the rubber washer is under the strings between the strings and the headstock. I thought that the washer was supposed to go between the strings and the string tree, in which case it would be on top of the strings acting as a cushion between the top of the strings and the underside of the string tree.
Can you take a different picture? Because in the one you posted, it really looks to be below the strings.
Ha! You're right. I just looked. I had intended to put it between the strings and the tree, but I just wasn't thinking and put it under the strings. The washer is thick enough, though, that it appears to have the same effect -- the string tree is pressing the strings onto it and dampening them. I'll try it the "right" way later today and see how it works. Thanks for pointing that out.
