Bare Knuckle Pickups Forum

Forum Ringside => Tech => Topic started by: Philly Q on December 07, 2008, 01:38:30 PM

Title: What causes dead spots?
Post by: Philly Q on December 07, 2008, 01:38:30 PM
I was playing my SG the other day and noticed a dead spot (at the 11th fret on the G string, to be precise  :roll: ). I play the note, it sounds for a couple of seconds, then dies.  All the "surrounding" notes sustain just fine.

I had a similar thing years ago on my EB/MM Axis (9th fret that time, I think!).

So, question - what causes dead spots?  Is it just something in the wood, or the wood and the truss rod vibrating in such a way that they kill the sustain somehow?  I don't suppose there's any way of "fixing" them?
Title: Re: What causes dead spots?
Post by: hunter on December 07, 2008, 01:55:38 PM
I also wanna know (has dead spot on beloved LP Special on G string 12th fret.
Title: Re: What causes dead spots?
Post by: Twinfan on December 07, 2008, 02:11:35 PM
I find that adding more relief to the neck (i.e. more of a bow) can drastically reduce dead(er) spots.  Thinner necks are more prone to it in my experience too, and it's usally around the middle of the neck on the G string.  Something to do with the thickness of the string, the frequencies etc is why it's the G.

More relief should help a lot.
Title: Re: What causes dead spots?
Post by: Twinfan on December 07, 2008, 02:20:35 PM
Great thread about the problem on the PRS forum:

http://forums.birdsandmoons.com/forum/showthread.php?t=1928&highlight=dead+spot%2A
Title: Re: What causes dead spots?
Post by: Philly Q on December 07, 2008, 04:27:52 PM
Great thread about the problem on the PRS forum:

http://forums.birdsandmoons.com/forum/showthread.php?t=1928&highlight=dead+spot%2A

Very interesting, especially what they said about the possible effects of changing hardware, and the longer heel on newer PRS guitars (if I could be bothered, I'd look on Ed Roman's site and see what he says about that, he always moans about those long heels  :lol: ).

My SG has a fairly fat neck, and better tuning stability than nearly all my other guitars - so I guess it's pretty rigid.  I'll see if it could do with a little extra relief, if that might help.  I'm also planning to replace the bridge with a TonePros at some point, maybe that will have some effect too.
Title: Re: What causes dead spots?
Post by: Twinfan on December 07, 2008, 04:48:36 PM
Yep - it's all about shifting the frequency resonance to somewhere that's not over a fret....
Title: Re: What causes dead spots?
Post by: WezV on December 07, 2008, 05:23:20 PM
I find the carbon fibre rods i put in most of my necks drastically reduce deadspots
Title: Re: What causes dead spots?
Post by: FernandoDuarte on December 07, 2008, 05:32:46 PM
I find the carbon fibre rods i put in most of my necks drastically reduce deadspots

Thanks for the tip 8)
Title: Re: What causes dead spots?
Post by: Philly Q on December 07, 2008, 06:00:48 PM
I think my Precision bass has graphite neck reinforcement rods.  Haven't noticed any dead spots, but I don't play it that much!
Title: Re: What causes dead spots?
Post by: badgermark on December 07, 2008, 06:27:39 PM
Possibly a slightly low fret? Had this problem with an epi a few weeks ago. Can't really see how something like a string vibrating can be affected by resonance of the truss.
Title: Re: What causes dead spots?
Post by: Will on December 07, 2008, 06:28:36 PM
Possibly a slightly low fret? Had this problem with an epi a few weeks ago. Can't really see how something like a string vibrating can be affected by resonance of the truss.

I dare you to search truss rod condom on the les paul forum.
I DARE YE! :D
Title: Re: What causes dead spots?
Post by: Philly Q on December 07, 2008, 06:52:37 PM
Possibly a slightly low fret? Had this problem with an epi a few weeks ago. Can't really see how something like a string vibrating can be affected by resonance of the truss.

No, it's definitely a dead spot, although my truss rod idea was probably nonsense. 

They're quite common and well documented - see the PRS forum link Dave posted above.
Title: Re: What causes dead spots?
Post by: jibidy on December 07, 2008, 07:32:18 PM
I thought that dead spots were mainly because bad frets. Eg if you have a low fret you get rattling from the next fret.

Or is that not what a dead spot is.

Also i noticed the 11th fret on my G string (epi SG) also is cr@p but because it rattles a bit. But its only that fret on that string.

Some kind of pattern in SG's? :?
Title: Re: What causes dead spots?
Post by: Philly Q on December 07, 2008, 07:42:19 PM
I know what you mean about notes "fretting out", but as I understand it a dead spot's nothing to do with high or low frets (although I've learned today there may be a dead spot under the fret). 

There's no fret buzz or rattle, this is a note that rings out perfectly normally but then "dies" very rapidly.  The note just won't sustain like the other notes around it, no matter how cleanly I fret it or how much distortion I have.
Title: Re: What causes dead spots?
Post by: FELINEGUITARS on December 08, 2008, 01:16:01 PM
Sometimes we have encountered a fret that kills the note too quickly ,
Sometimes it is caused by the resonance problem affecting that particular frequency

Other times it can be caused by a slightly loose fret , which doesnt sound like a rattle , but does soak up the strings energy and we have been successful in rectifying this by bleeding a little thin superglue under the fret and into the slot.

I recommend wiing a little wax (like furniture wax) either side of the fret with a Q-tip to stop the glue sticking to the fretboard and making a mess if you are going to try this.
And have some tissue or rag handy to mop up any excess glue in a hurry too.
Title: Re: What causes dead spots?
Post by: BadMonkey on December 08, 2008, 02:34:29 PM
I can't offer any help other than to say my Gibson SG Standard has a dead spot on the 11th fret on the G string!

Title: Re: What causes dead spots?
Post by: Philly Q on December 08, 2008, 10:46:43 PM
Oh well, it seems to be a pretty common problem!

Thanks to Jonathan for the tips  :) .  If I decide to try gluing the frets I may not risk it myself - I'm pretty good at guitar DIY but I've had a few accidents with superglue.... it's so thin and it sets so bloody fast.
Title: Re: What causes dead spots?
Post by: ToneMonkey on December 16, 2008, 04:36:13 PM
Isn't this what those Tone Finger things are for.  Although I always thought that they would just move a dead spot rather than fix it.
Title: Re: What causes dead spots?
Post by: WezV on December 16, 2008, 04:47:41 PM
yeah, the tone fingers can help , worth checking with a clamp first
Title: Re: What causes dead spots?
Post by: Philly Q on December 16, 2008, 04:58:29 PM
yeah, the tone fingers can help , worth checking with a clamp first

Is that like the Fatfinger thing Aspen Pittman makes?  I don't think it would be ideal on an SG, they're neck-heavy enough already.

Funny how the idea of that device is to add more mass at the headstock, like a set of die-cast tuners - whereas other manufacturers say tuners should be as light as possible for the best tone.
Title: Re: What causes dead spots?
Post by: Twinfan on December 16, 2008, 05:14:01 PM
But the Fat Finger adds mass to move the dead spot to somewhere not over a fret  ;)  That's why peopl ethink it adds sustain etc