Forget Fatfinger I found the deadspot fix!

[Fullerton50sFan]

Your description starts out OK. The snag you hit is the hard end point assumption - if it were a hard end point, you wouldn’t have dead spots.

The neck on your bass is a mass loaded bar, with distinctly assymetric end masses, and a non linear cross section, made of a very non isotropic material (wood). It has resonances (multiple frequencies where it resonates), and where the nodes and antinodes line up with the end point of a string trying to resonate at the same frequency, you get variations in how long the string resonates. When you get a combination of neck position and string tuning with a very short sustain time, we call that a dead spot.

Note that the dead spot is a result of two resonances (the string and the neck) at the same frequency. If you change either - by retuning the string, or by changing the mass loading at the headstock, the dead spot can moved or minimized practically. I have basses where I needed lighter tuners to make them work well, and one bass where I needed heavier tuners - it's tuned in D standard, so it called for a different solution. It had a dead spot on the open G string (the location where you usually have an A string), and the added mass was needed to move the dead spot down in frequency.

Hard endpoint where it gets reflected and
phase inverted;no phase inversion,no phase
cancellation,no dead spot. I understand how
increased mass lowers the frequency,decreasing
it raises it. How is a notes volume,sustain and
harmonic content diminished if it isn't partial
phase cancellation? If you agree that it is but
not from the machine head could you describe
the signal path. Where and how is energy being
taken from the string? Inquiring minds want to
know.

 

[saabfender]

Though, because it involves sound, it should have, in addition to pics, before+after soundclips- especially being that the author is a PHSA syndrome sufferer.

I spent about 5 minutes looking for this thread and couldn’t find it yet here it is!

On my fretless Jazz I took loose the D and G strings. Well, first I made a Before recording. Then I played some with the strings off the tree. Then I made a recording with the gizmo I made.

It’s a large faucet (neoprene?) washer I had in my stuff, little washer and longer screw. It’s not cinched down all the way, since the washer is flat side down.

The “Without” was really good but the breakover angle was too slight. The “After” clip was different also.

I don’t know about dead spots. My impression is that those were ironed out some. What I did notice is the original ringy midrange honk of the G and to a lesser extent D (which was initially less effected) is cleaned up. All the strings across the bass match better tonally. I’d understood that sound to part of the bass itself and may miss it at first.

The modification stays.

 

[MattZilla]

The Score:

Faucet Washer: 1
Fender Washer: invisible

 

[micguy]

Where and how is energy being
taken from the string? Inquiring minds want to
know.

Energy is lost at the ends of the vibrating portion of the string, because the fret/neck and bridge/body end points are not infinitely stiff and massive. Kind of like when you bounce a basketball, the floor moves some. The bridge/body is more like the gym floor (moves less), the fret/neck is like bouncing the ball on your living room floor - more vibration ends up in that in the floor, as it isn’t as solid. If you made a neckless bass -2 heavy bridges on a big, thick body, the string would have two solid ends, hence more sustain.

 

[micguy]

What I did notice is the original ringy midrange honk of the G and to a lesser extent D (which was initially less effected) is cleaned up. All the strings across the bass match better tonally. I’d understood that sound to part of the bass itself and may miss it at first.

The modification stays.

View attachment 3132071

 

[micguy]

If you’re talking about high freq ringing (zing) that’s associated with new strings, I could see that helping. The zing is likely compressional waves - the string does’t move sideways, it moves towards the bridge, and away from it. Those waves would go past the nut, and that washer would help damp them.

My worry would be the increased friction at the string tree, and possible tuning issues from that.

 

[Fullerton50sFan]

Yeah, my experience has been that dead spots coincide with notes occurring with the necks resonant frequency. Often these dead spots are easy to predict before the neck is even attached to the body.

The idea of using rubber washers/grommets on the "non ringing" portion of a string is well documented on upright basses and in particular on mandolins. It's not for dead spots but rather sympathetic vibrations that can get out of control! Sorta opposite of what the OP is preaching.

Is that to say that after all that fiddling around the OP did not indeed notice some changes? Of course not! Just that dead spots on an electric bolt on bass neck are already well diagnosed. I would need to see a LOT more basses cured with rubber washers before I start considering this anecdotal evidence as gospel.

Still, a very interesting thread to review!

You seem friendly so I'll try again. a plucked
string sends a wave up the string,over the nut,
under the string tree to the machine head
where it is reflected and phase inverted. It
then travels back over the nut. Two traveling
waves,opposite direction,same frequency,
phase inverted passing through each other,
causing partial phase cancellation.
On the G string because it is the lowest mass,
but the highest tension,mounted at the highest
and most flexible (resonant)part of the neck.
It occurs on notes bracketing C# because that
is an anti-node,a region of greatest oscillation.
Your description of classical instrument damping tecniques is in response to a similar
phenomenon only phase coupled,they call them
wolf tones. I am using rubber washers over and under the strings at the string tree as a
damping medium under compression to intercept that phase inverted wave. It has greatly improved the volume,sustain,and
harmonic content of my formerly anemic C#
which would last 2 to 3 seconds,leaving an
octave harmonic that died a few seconds later.
I am well aware of placebo effect and
confirmation bias,that's not what is happening.
I tested by doing three note runs using double
hammer-ons,light,medium and hard at slow,
medium and fast tempos.
Since I studied the physics,tested the hypothesis and had it validated to my satisfaction I joined this forum to share it.
the push back was stunning.
Over this weekend I attended a workshop
featuring a very talented guitar player with a
degree in world music playing a variety of
stringed instruments.In the audience were a
custom guitar builder,an amp designer,and an
engineer who I shared my idea with.
They all thought it sounded plausible; above
all they were civil. I've decided I'm going to stay in that world. Thank you for your interest.

 

[MultiScaleMale]

You don't have to hit return after each line, just keep typing and the browser will take care of the formatting.

 

[MattZilla]

over and under the strings at the string tree

this is why pics are needed. I read all of your posts and typically pick up on subtle tidbits, but this is the first that I'm imagining more than one fender washer. It's 2018. Take a picture of the front of your headstock, then of the non-tuner side of your headstock, then edit your op with the addition of those two essential pics which would've saved you at least one paragraph per post. With all due respect, holy moly.

They all -said that they- thought it sounded plausible

in person, it can make someone feel better about themself to sacrifice honesty so as to project a life's accumulation of practiced tact and poise, not just to those around them, but to themselves as well. Those truly skilled at that game edge right up to faux-humility without crossing into it.

You brought to teh interweb a claim and thoroughly refused to substantiate it. There's tons of really nice people on this forum, but it's still the internet- grandma's hugs are nowhere to be found here. There is a currency with which dishonest politeness can be bought here, but 1) it also tends to buy unwanted invites for romantic coffee/sushi dates 2) you probably don't have it.

Pics and soundclips.

 

[cataract]

I’m still at a loss here. Wouldn’t at least ONE of the many instrument companies or niche reknowned luthiers (creators of extraordinarily engineered works of art) have at least already addressed this in some way, with some sort of practical solution, if it were in fact an actual issue like you are saying?
It’s not “push back”— it’s common sense.

 

[scotch]

You seem friendly so I'll try again. a plucked
string sends a wave up the string,over the nut,
under the string tree to the machine head
where it is reflected and phase inverted. It
then travels back over the nut. Two traveling
waves,opposite direction,same frequency,
phase inverted passing through each other,
causing partial phase cancellation.
On the G string because it is the lowest mass,
but the highest tension,mounted at the highest
and most flexible (resonant)part of the neck.
It occurs on notes bracketing C# because that
is an anti-node,a region of greatest oscillation.
Your description of classical instrument damping tecniques is in response to a similar
phenomenon only phase coupled,they call them
wolf tones. I am using rubber washers over and under the strings at the string tree as a
damping medium under compression to intercept that phase inverted wave. It has greatly improved the volume,sustain,and
harmonic content of my formerly anemic C#
which would last 2 to 3 seconds,leaving an
octave harmonic that died a few seconds later.
I am well aware of placebo effect and
confirmation bias,that's not what is happening.
I tested by doing three note runs using double
hammer-ons,light,medium and hard at slow,
medium and fast tempos.
Since I studied the physics,tested the hypothesis and had it validated to my satisfaction I joined this forum to share it.
the push back was stunning.
Over this weekend I attended a workshop
featuring a very talented guitar player with a
degree in world music playing a variety of
stringed instruments.In the audience were a
custom guitar builder,an amp designer,and an
engineer who I shared my idea with.
They all thought it sounded plausible; above
all they were civil. I've decided I'm going to stay in that world. Thank you for your interest.

Testing on more than one instrument would be immeasurably more valuable than altering your playing technique on that one bass, don't you think?

Again, I'm still all ears, but I admit I'm skeptical of a single incident equaling a proven solution.

 

[MultiScaleMale]

I hope you don't think I'm being uncivil by disagreeing with your observation. But it's the neck resonance that causes dead spots. When you fret a C# (we'll assume that's the dead note), the string is transferring energy into the neck via the metal fret that is pressed into the neck. The portion of the string above the fretted note has insignificant amounts of vibration and are effectively out of the equation.

 

[TomB]

...not sure, but I think OP said good-bye. Has anyone actually tried OP's mod (due respect to @saabfender, but yours is different)?

 

[lz4005]

You don't have to hit return after each line, just keep typing and the browser will take care of the formatting.

He does. Because of phase inversion and hard end points.

 

[MultiScaleMale]

He does. Because of phase inversion and hard end points.

Burn!

 

[cataract]

Pretty sure this is just 6 pages of troll thread. Amazing.

 

[saabfender]

Pretty sure this is just 6 pages of troll thread. Amazing.

Pretty sure not. I changed one guitar for the better with no expense and will look at doing another based on ideas from this thread. TB is truly amazing.

 

[cataract]

Pretty sure not. I changed one guitar for the better with no expense and will look at doing another based on ideas from this thread. TB is truly amazing.

 

[saabfender]

Wouldn’t at least ONE of the many instrument companies or niche reknowned luthiers (creators of extraordinarily engineered works of art) have at least already addressed this in some way, with some sort of practical solution, if it were in fact an actual issue like you are saying?
It’s not “push back”— it’s common sense.

Why does Gibson insist on making electric guitars with a ridiculous headstock angle and tuners that are not inline with the course of the strings, making their guitars Hell to keep in tune, as well as fragile?

Fender stuck that thing there ages ago as a half-assed workaround. "Tradition" dies hard in those parts. Just looking at the black thing I put together compared to the silver thing before is producing a little aesthetic dysphoria.

Not a lot of money to be made in addressing the issue. You could get what you need at Home Depot for less than three bucks.

 

[saabfender]

Pics and soundclips.

I had made a couple of recordings of a chromatic scale on the G string. While you could hear a difference, I thought I'd run them backward so you could concentrate on the body of the note. Any resonant noise might present itself as an overarching sound. Shame on me for not using a metronome. For shame.

And the picture again.