What is a 'dead spot'?

[tb-player]

In all the time I've been on TalkBass, I've heard repeatedly about dead spots. During that time I've owned a lot of basses and I don't recall ever encountering this. I play up and down the neck and everything always sounds fine to me.

When you guys/gals are experiencing dead spots, what are you hearing/feeling? Or is it less frequent than it seems. Maybe I've just gotten lucky??

 

[Five or Six]

When the neck responds normally sound wise at all frets on all strings. Except for say the "D" on the "A" string. It's more if a "thunk" or dead sounding note on the neck. The string makes very little or normal sound at that fret. Dead sounding, dead spot. Does that help?

 

[Deleted member 365158]

I’ve been curious about this too.
My basses range from an ibanez musician to cheapo Glarry’s. Most of them have been modded from just different pickups to full on electronics and hardware changes and even different necks and re shaped headstocks. None have noticeable dead spots… at least to me.
I thought my Ibanez EX had a dead spot but it was actually the string, a string change and a tweak to the setup and it was A-OK.

There is a lot of talk around here of dead spots, could someone post a video and/or audio of it?

 

[jmattbassplaya]

In general, I think the issue is over exaggerated. I’ve only had one with a very noticeable dead spot, and that was an old StingRay 5HH. The low D on the B string was completely nonexistent. You’d be playing in the context of the band, land on that note, and it was as if the bass got sucked completely out of the mix.

 

[chadhargis]

Ah...I thought this was a thread about my bedroom.

 

[Killing Floor]

The boring answer is resonance. Not the “this guitar rocks! It’s so resonant”. But actual resonance. It’s rapid damping caused by a specific frequency that varies by material type, mass, etc. Every object has resonant frequencies. But on some guitars you notice them less or not at all. I only have one bass that really sinks on the 7th fret G string. Some basses have a dead spot that’s obvious and some you barely notice.

 

[Michael Stanley 2112]

Ah...I thought this was a thread about my bedroom.

Or the place in the woods, where all the zombies live?

 

[mongo2]

Or the place in the woods, where all the zombies live?

Zombies live? Is that one of those oxymorons?

One of the reasons I switched to shortscales is I've found them much better than longscales at controlling dead spots. Of the many shortscales I've had I've only had one with a slight deadspot. I think the better performance of shortscales is due to the shorter neck being inherently stiffer than a longscale neck. With my longscales only one is without a deadspot, it's an Allparts one piece maple neck that's very stiff.

 

[el murdoque]

G string fifth fret is a popular one for Fenders and FSOs.
The string sounds like it has been on a year too long. Less ring, less sustain, not many overtones.

 

[Michael Stanley 2112]

Zombies live? Is that one of those oxymorons?

One of the reasons I switched to shortscales is I've found them much better than longscales at controlling dead spots. Of the many shortscales I've had I've only had one with a slight deadspot. I think the better performance of shortscales is due to the shorter neck being inherently stiffer than a longscale neck. With my longscales only one is without a deadspot, it's an Allparts one piece maple neck that's very stiff.

If I could find a 24 fret short scale, I might give it a shot. I'm less-abled, now and I have to sit to play. A shorter scale would be a God-send.

 

[taketwo]

As I understand it, it's the frequency where the neck resonates with the note and absorbs its energy. I can hear this on my bass on the 6th fret of the G string, where the fundamental dies away quickly leaving the second partial as the main tone. Suggested solutions include adding weight to the headstock to move the deadspot to a lower frequency, or the opposite to raise it. It's a (the?) motivation for headless bass designs.

 

[mongo2]

If I could find a 24 fret short scale, I might give it a shot. I'm less-abled, now and I have to sit to play. A shorter scale would be a God-send.

I'm also less-abled due to a minor stroke a few years ago and I also sit when I play now. I've been using shortscales and longscales for over 50 years but in the late '90s I started to switch to only shortscales.

My 24 fret shortscale of choice is an early '60s Silvertone Model 1444 by Danelectro. They now make reissues of that and the Longhorn bass, both have 24 frets.

My most frequently used shortscale now is a Hofner Ignition Club bass which is very lightweight and has 22 frets.

 

[DrBnz]

OK but I gotta tell a short story. So in aircraft vibration analysis they first do studies of the components to know the Resonant Freq of each piece and of the assembly as a whole. Meaning you take each item and you place a vibe measuring instrument to it (accelerometer) and then you "excite" the piece by striking it with a calibrated hammer. As it rings out the recorded vibe data identifies that piece by a freq. By knowing this you can monitor component health (from a vibe perspective) and often foresee impending failures. An example being a pump vibe that is slowly increasing in vibe amplitude over time. Now since you know what a normal one looks like (cause you've been collecting and comparing data on the fleet of aircraft for years) you can decide to overhaul it early and avoid the failure. OR use that data to extend the service life if it seems to be performing normally. So we can see not only the pump, but the gear within, or the bearings.... So that is "resonant freq"... now flip your thoughts to knowing that aircraft also use a form of noise cancelling features to cancel out vibes that may impact crew health and comfort. So we produce a vibe (i.e. counter-rotating force generators) at the same freq as the offending vibe and it greatly reduces the felt affects (it doesn't "cancel" it). So now to a bass. All components have a resonant freq.... So does the assembly as a whole. Most (of mine) you can hear on the G string between the 5 and 7th frets. You should also be able to hear it (but to a lesser degree) at multiples of that same freq.... 2x.... 4x....etc...) So the theory is.... when you hit "that note" which is the same (freq) as the resonant freq that is found on the bass, the frequencies oppose each other and deaden the sound produced. Now to change the resonant freq of a bass, you have to change the weight / density. The problem is.... if you add mass to move that freq, you'll only move it to a different location on the neck. Meaning you'd have to add enough to change it enough for that freq to fall outside the range of the neck. I don't know what that is..... is that a 40lb bass? Keep in mind you'd still hear the harmonics (2x... 4x) I dunno. Is any of this true? I dunno.... but it does make sense. Regardless..... Its such a small impact that many people don't even hear it.

 

[Zooberwerx]

As I understand it, it's the frequency where the neck resonates with the note and absorbs its energy. I can hear this on my bass on the 6th fret of the G string, where the fundamental dies away quickly leaving the second partial as the main tone. Suggested solutions include adding weight to the headstock to move the deadspot to a lower frequency, or the opposite to raise it. It's a (the?) motivation for headless bass designs.

Yep...this is a component of the attack envelope or "decay". There are a few trials where a thumb-clamp was added to Fender-esque headstocks with some mass added beneath (...quarters?). It can help. I found it more interesting that the responses varied as the mass was re-positioned around different points on the headstock. The big questions are:

*Where is the optimal location and is there any consistency bass-to-bass?

*How much mass and, again, is there reproducibility among the test subjects?

I recall seeing a mod where the Fender machine heads were removed, holes drilled, and weighted slugs inserted (4 per tuner). What if we can ID a single "sweet spot" and apply like compensation?

Riis

 

[Slevage]

My 1977 Stingray had the notorious 7th fret, G string dead spot without a doubt.
Note is D.

When you vibrate anything at its resonant frequency, the object absorbs the energy.

 

[SLO Surfer]

I have only experienced dead spots on my fender shaped basses, and those dead spots are always around the 5th through 7th frets. I think it’s because these instruments have so much G string length past the nut across the length of a really long headstock. I would guess these typical G-string dead spots on Fenders are why Leo invented the Sting Ray shaped headstock, with much less G string length stretched across a much shorter headstock.

I only found these dead spots once I started using octave pedals, because the pedal wouldn’t track those dead spot notes. That’s what made me aware of and pay attention to them. Now I can hear the dead spots acoustically where I didn’t even notice them before. I don’t think they’re audibly obvious or noticeable to an audience or even other band members, unless your octave effect stops tracking and drops out on only those notes. These days I ignore and play right through the dead spots, or sometimes use them as part of the instruments timbre. Sometimes I avoid those notes and play them up higher on the D string to ensure the full sound is present, if I’m motivated. In any case, dead notes don’t bother be unless I’m using an octave pedal.

The best description of dead spots for those who haven’t experienced them or know what they are is this;

G string fifth fret is a popular one for Fenders and FSOs.
The string sounds like it has been on a year too long. Less ring, less sustain, not many overtones.

 

[tb-player]

I dunno. Is any of this true? I dunno.... but it does make sense. Regardless..... It’s such a small impact that many people don't even hear it.

Or many people read about it and now think they hear it when it’s actually bad technique, old strings or an excuse to buy a new bass… lol.

I’ve owned 50+ basses and never noticed it once. After reading these explanations, I’ll chalk it up to exaggerated TB lore, based in a modicum of truth (I’m looking at you ‘neck dive’).

 

[Mike Marshall]

If I could find a 24 fret short scale, I might give it a shot. I'm less-abled, now and I have to sit to play. A shorter scale would be a God-send.

Longhorns have 24 frets

 

[sxaxsx]

Yeah I never experienced this either, but I like really old flatwounds so maybe I just wouldn't notice?

 

[Tim Skaggs]

It’s physics, and pretty well explained by @Killing Floor

A vibrating string, fretted or open, has contact points on each end; nut & bridge or fret & bridge on a bass. Whatever the end points consist of, they both have a resonant frequency, and in the case of a bass, the two end points are attached to each other through the neck & body, so they might have a common resonant frequency. If one or both end points have a resonant frequency very close to the frequency of the vibrating string, or a resonant frequency very close to a harmonic of the vibrating string, the end point(s) will also vibrate when the string is plucked. If the end points vibrate, they will absorb the energy of the vibrating string & the vibration of the string is greatly dampened or mostly stopped.

An example of the energy absorption has been experienced by about anyone who has operated one end of a jump rope. If the other end of the jump rope is tied to something solid, like a fence post, you can swing the rope well. If the other end is tied to something not so solid, like the wire between two fence posts, you can’t swing the rope as well. It takes more of your energy to keep the rope swinging because the movement of the wire is absorbing the energy you are applying to swing the rope.

Pretty much every bass, and other stringed instruments, have some degree of “dead spot” somewhere in its frequency range. Those basses made of a material other than wood often have less chance of the problem because the “non-wood material” has a resonant frequency outside the frequency range of a standard tuned bass. This is no guarantee; some non-wood basses still have slightly dead or weak notes.
Those that have owned dozens of basses and have never noticed a single one of them having a single dead spot anywhere are not the owner of very unique basses, they are just very unique people.

A piece of advice; don’t look too hard for dead spots on a bass or other stringed instrument, because once you know how dead spots sound and feel*, and also discover on which notes they are the most common, you get to the point where you can’t avoid noticing them.

Edit: I would define the term “dead spot” as being discussed here as: “a note where the fundamental frequency has less sustain than other notes of different, but relatively close by frequencies”. Just clarification that “dead spots” aren’t totally dead; they are just varying degrees of “weaker” when compared to other notes on the same instrument.

*(yes, you can feel dead spots on a bass from the vibration in the body & neck. The note where you can feel a significant body vibration is usually the dead spot. I’m pretty sure I can find the dead spot(s) on most electric basses while listening to moderately loud recorded music in earbuds with the bass un-amplified / unplugged)