Rattling open string and odd harmonic sound?

[iBudd]

Hi guys – long time lurker here, there’s a lot of expertise in these forums!
I hope you’ll be able to help me with a couple of niggling issues on my bass.

I have a ’95 MIJ Jazz. Always strung it with rounds 40-60-80-100 (Rotos or, um, bass centre own brand ones) until a couple of years ago when I tried some TI Flats and liked them. I had the bass set up professionally when I switched to the flats, as I figured the low tension would need a bit of fiddling around and didn’t fancy doing it myself.

Since then a couple of niggling issues. First the open A string rattles when it’s plucked hard(ish). A split second after the note there’s a rattle as the note decays. I thought it might be that the slimmer string was rattling in the nut slot but when I experimentally switched back to the old rounds the rattle was still there. If I pitch the string up a couple of semitones it goes away. Similarly if I raise my action up very high or pull the headstock back (gently!) to straighten the neck the issue goes away – I presume because the string is under more tension and has less liberty to flap about. I’ve got a good break angle on the string with plenty of winds so I don’t think it’s the classic Fender design flaw!

So I thought I might need to turn my truss rod so maybe the strings would be under more tension? – To find out I lowered my action right down and it’s the notes above the 12[sup]th[/sup] fret that choke first, the lower notes still ring out. So do I need to actually tighten the rod and get less bow? I thought the lower tension TIs would have meant that I needed to loosen the rod? Presuming the tech who set me up didn’t do it. I’ve totally confused my diagnostic brain either way.

The other issue is an odd one. I can’t hear it acoustically, but when amplified there’s a strange metallic sort of scraping or clanking sound when I play low down the neck, almost like a slight harmonic overtone. Hard to describe. It’s not loud but it is a bit irritating. Rolling off treble helps but doesn’t entirely cure it. I was wondering if these two issues were connected somehow.

I’ve lived with these two niggles because in truth I haven’t been playing much but recently I’ve got some recording work and it’s highlighted these problems so I want to straighten these problems out before I take on any more.

I’m happy to do any bit of fixing that is within the realms of the enthusiastic amateur. Got tools and not afraid of a truss road. These days I actively want to learn more to able to do these kinds of things myself. (Plus my nearest tech is a couple of hours away!).

All advice and wisdom gratefully received.

Edited October 31, 2011 by iBudd

[brensabre79]

It sounds like the strings are catching at the top end of the neck due to the neck angle rather than the truss rod adjustment (especially if it has been set up right). I reckon you might need to shim the neck-Theres a tutorial on here how to do it - its really quite simple. You will need to set it up again afterwards though as the bridge height will change and therefore the intonation along with it! This issue can be got around by increasing the action height, but if you like a low action the shim is a good place to start, its completely reversible and it will cost nothing to do!

All that said, there are limitations in how low the action can go - depending on your playing style.
I went through a re-fret and several set ups with a very good luthier here in Brighton on my Sabre before I realised I just have to play a bit lighter or increase the action height to avoid fret buzz!

This might sort out the other issue but if its only coming through the amp (not acoustic) it opens a can of worms in terms of the electronics in the instrument or the amp. i had a lovely rattle through my practice combo that turned out to be a dry joint. I'd get the bass working from a mechanical point of view and see what happens with the other...

[iBudd]

Thanks, I hadn't thought about shimming the neck, I think I'll look into that... but it's only the open A that rattles, and fretted notes doesn't, as I understand it the shim would allow me to lower the action more uniformly... but if it's only the headstock end of the neck, is that a clue that it's the curve of the neck rather than the angle that's the culplrit?? I tried raising up the nut slot a little, little temporary shim with folded paper, and that achieved not very much.

I usually play with a pretty medium action anyway, not Jamerson-height but I do like to have room to dig in a little for more r&b stuff.

One very odd thing I've noticed is that if I hold the headstock moderately tight with my hand and play the open A it doesn't buzz. What on earth could that mean?

As for the other issue, I do have a feeling they're connected as the strange harmonic sound is only really audible when I play on the lower frets. It's actually very faintly audible acoustically so I don't think it's an electrical issue but I'll be happy to get in there with the soldering iron after I get the rattle sorted out. That's territory where I do feel a bit more comfortable. Actually now I think about it I have basically replaced every bit of wiring since I first noticed the odd noise (it turned up on a recording I did some time ago) since I had a pot that died and I took the opportunity to tidy up the harness. So I suspect it is mechanical rather than electrical - but I'm not ruling anything out!

It's all a bit of a mystery, I guess I'll have to start experimenting! Thanks again for your help. I had a lovely 4 years living in Brighton (Hove actu.... ), enjoyed it greatly.

[steve-bbb]

see if a quick string swap solves the problem!

have had a very similar problem just recently - a guitar techie mate did a setup on my neck and when i got it back after a short time i noticed a very high pitch harmonic whistling only on the open D and nowhere else - after a bit of examination it turned out it was exactly the harmonic at the position roughly two thirds between 2nd and 3rd fret

the nut angle was fine and the frets were ok and the windings so my tech suggested it was most likely string - to which i was initially sceptical - however he removed the d string and replaced it and the problem stopped immediately - just to recheck we put the original string back on and the harmonic whistle started up again

because id changed the strings at about the same time as giving him the bass to setup i didnt really appreciate that it might have been the strings and assumed it would be a high fret somewhere or something to do with his setup as i was aware that he had indivisually addressed a couple of high spots on the A/D/G 2/3rd fret area

edit- just to add - exactly the same as yours - it was only the open string that made the whistle and not when fretted at all

Edited November 2, 2011 by steve-bbb

[iBudd]

I did try swapping off the flats for an old set of roundwounds I had kicking about. Curiously both issues actually got slightly worse, the rattling open A and the whistly harmonics.

The whsitly harmonic issue is a really odd one to describe - it's like a faint harmonic overtone related to the actual note I'm playing, or the finger noise associated with it! It lends the note a slightly 'hollow' quality. I've been really watching my technique and I can limit it with better fretting and so forth. I can also dial most of it out with the tone control. It's actually a very minor issue but my instincts tell me that the two things are connected so it might be a clue to the rattly A issue. I think because of it's harmonicy nature I'm sort of thinking it must be something to do with proximity of strings to frets in the lower register, but I might be well wide of the mark!

Thanks for your help Steve!

[brensabre79]

[quote name='iBudd' timestamp='1320242404' post='1424198']
Thanks, I hadn't thought about shimming the neck, I think I'll look into that... but it's only the open A that rattles, and fretted notes doesn't, as I understand it the shim would allow me to lower the action more uniformly... but if it's only the headstock end of the neck, is that a clue that it's the curve of the neck rather than the angle that's the culplrit?? I tried raising up the nut slot a little, little temporary shim with folded paper, and that achieved not very much.

I usually play with a pretty medium action anyway, not Jamerson-height but I do like to have room to dig in a little for more r&b stuff.

One very odd thing I've noticed is that if I hold the headstock moderately tight with my hand and play the open A it doesn't buzz. What on earth could that mean?
[/quote]

Sorry, misunderstood the first post. So is the rattling at the headstock end? Could be one of the machineheads or ferrules there is a bit loose... Or maybe even part of the truss rod assembly rattling?

[iBudd]

Loose headstock furniture was my thought too, but everything seems as it should be. I suspect the open string is rattling against the 1st or 2nd fret - plus if I look closely the string isn't vibrating uniformly, as if something is impeding it's vibration. I experimentally pitched the whole bass up a tone and and a half (except the A string) - to simulate the effect of greater tension on the front of the neck - and the rattle almost went away, which makes me think that it might be a truss rod issue after all - if the TIs are very low tension strings then they're not exerting enough pressure to counter the truss rod force, hence release the rod a bit = everything fixed. Maybe?

I had the bass set up when I first put the TIs on but in all honesty it wasn't a great job. Which kind of made me want to get better at doing this sort of stuff myself. Perhaps the tech underestimated the amount of rod adjustment the bass would need going from roto rounds to Ti flats. Also that might account for the odd overtone - perhaps the vibrating strings are interacting minutely with the frets...

It all sort of makes sense I guess. Thanks for all your input so far guys it's much appreciated.

[Andyjr1515]

Hi
Sounds more like the nut slot on that string is set a bit low. It could also be, as Brensabre79 says, the angle of the neck. However, no point on checking either until double checking the neck relief is broadly OK.
To check the neck relief, get a friend (or capo) to hold down the E string at the first fret, hold down also at the 16th fret and then press the string up and down at the 8th fret (told you you needed a friend or capo ) If there is perceptable movement (more than nothing but less than 1mm), then its broadly OK. If the string is hard on the 8th fret, loosen the trussrod (small movements at a time), until there is between 1/2mm and 1mm gap at the eighth. If gap is way over 1mm, you need to tighten the truss rod - this is a bit iterative because you need to loosen the strings before you tighten the truss rod and then retune the strings before checking the gap
Once the neck relief is checked, then look at what distance the string is from the fretboard at the nut. If your troublesome string is much closer than the rest to the fretboard, the nut slot may have been filed a bit too far. As a very (VERY) broad guide the gap should be around the same as the first fret is deep and so, when fretted at the first the string is broadly parallel to the fretboard.
If that is OK, then check the neck angle - find a straight edge long enough to reach the bridge while running along at least 5 frets-worth of fretboard. Run it along the frets towards the bridge, with the bridge saddle at its lowest setting, and the straight edge should meet the bridge on, or just below, the appropriate saddle. If it is way below, you need to shim the body-end of the neck, if it is way above, you need to shim the headstock end.
If that is all OK, it could be some slightly proud frets or slightly low action or something completely different - but worth checking the above first and in any case!
Hope this makes sense and helps!
Andy

[iBudd]

Thanks Andy, that's a wealth of good information there!
My very first thought was a nut slot cut too low, I was all ready to reach for the baking powder and superglue, but on inspection it's actually alright. If I fret a B natural and look between the nut and first fret the string actually travels ever so slightly downhill from nut to 1st fret. So I reckon that's not the problem. It might even be cut not deep enough!
I've checked the action a few different ways - I like your method though. Fretting at 1st and 16th fret I do have some clearance at the 8th, but not very much at all. A little tap produces a tiny click. I can get feeler gauges up to 10 in there before they start to drag.
Running a straight edge up the neck doesn't seem to show any major relief either, but I only have a 15" straight edge to hand so I can't do the whole neck...
As you can probably tell I'm finding the diagnostic part really tricky. There's not one glaring thing that's causing the rattle...
But your advice gratefully received of course!

[retroman]

Neck angle shouldn't really be the issue unless you have reached the end of the height adjustment on the bridge screws.

Rattles can be caused by loose parts on the headstock parts, nut slot too low, truss rod too tight, or bridge saddles vibrating against each other. I get the bridge saddle issue occassionally with Fender type basses I have here. Setting the outer saddles at a slight angle using the height screws helps, as the outer strings will pull slightly inwards, and pull the saddles tight together. A combination of faults can cause weird string rattles as well, eg, nut slot too low, and over tightened truss rod will cause an open string to rattle, and cause a weird rattly buzzing noise between a fretted note, and the nut.

Harmonic issues, I would first swap to a spare set of strings, and see if the problem goes away. I have had a duff string in a set before, that had a weird harmonic over tone to it, and sounded completely out of balance with the rest of the set. Also, if the pick up heights aren't correctly set, you can get some odd harmonic noises. The pickup closest to the neck should always be further away from the strings, than the pick up closest to the bridge.

Well worth learning the art of setting a bass up, as set ups are a very personal thing......One mans perfect set up can be another mans unplayable!

Might be worth letting us all know where in the country you are based, as some kind hearted bass chatter might be willing to help you out

[Andyjr1515]

[quote name='iBudd' timestamp='1320261642' post='1424587']
I've checked the action a few different ways - I like your method though. Fretting at 1st and 16th fret I do have some clearance at the 8th, but not very much at all. A little tap produces a tiny click. I can get feeler gauges up to 10 in there before they start to drag.
Running a straight edge up the neck doesn't seem to show any major relief either, but I only have a 15" straight edge to hand so I can't do the whole neck...
[/quote]

Sounds OK - as long as there's a gap and it's not too big, its probably OK. Clearly, the nut slot is also OK. Maybe we're into the other things Retroman has talked about

[iBudd]

Thanks guys - really appreciate your help. I'll think on and explore some of the things retroman mentioned.
I'm in Cambridge by the way, I'll update my profile to show that...
Thanks again

[Lozz196]

Can sometimes happen on the A. Make sure the winds are low down on the tuning peg. That little "thingy" does this on the D & G, keeping the angle of the string from the nut to the peg downwards, and it usually prevents any buzz on these.

[MoonBassAlpha]

I had an odd sound at the nut on open D after i recut the nut slot a bit lower - I'd got the slot angled ok and there was just enough break angle, but it buzzed open, and wasn't immediately obvious why. In the end I worked it out and cut the slot even lower but with a too-narrow round file - the slot was a bit too wide or flat bottomed, and cutting it a fraction deper but narrower gave the string just enough support to stop buzzing when open. This was a very subtle thing, but may be worth checking out in your case.

[The Dark Lord]

Check out this video. Zoom through to about 3 min 38 secs. He gives some good info about how A strings commonly rattle. Do what he says and it'll probably fix it.

[url="http://www.youtube.com/watch?v=G5zUc6S4QV8"]http://www.youtube.com/watch?v=G5zUc6S4QV8[/url]

[iBudd]

Thanks mercuryl, that's a great little video. I've already got the string would down as low as it will go on the peg so the break angle is as great as you can get on a Fender bass. MoonBassAlpha, that's a good tip too, I might look more closely at the nut - but two things seem a bit odd about pursuing that as an idea - firstly the rattle sounds a split second [i]after[/i] the open string note, which itself sounds cleanly. You'd almost think there was some sort of sympathetic rattle being triggered by that particular pitch but I can't find anything that's not locked down! If I pitch the string up by 2 semitones it goes away. If it was a nut issue I'd expect the actual open note to sound buzzy. Secondly, I usually rest my hand over the neck pickup and pluck there. If I move my plucking hand to the neck/body join and pluck there the rattle goes away completely. Obviously that's not a permanent solution but maybe it provides us with another clue as to what's going on?
Really grateful for everyone's advice and help.

[Ou7shined]

My '80 G&L L-1000 has a 440Hz rattle too. Try as I might I've never gotten to the bottom of it (and I've heard of many other similar stories). I get the feeling it's coming from the tr. But as it doesn't get amplified, I just treat it as a quirky foible and live with it.

[iBudd]

actually that's a good point Ou7shined - my 440Hz rattle is being amplified but only slightly. Hmmm 440Hz Rattle might have been a good username.
Anyway in a fit of pique I've swapped off the TI flats and put back on some roundwounds I had kicking around. Already things feel and sound much nicer. The rattle is still there but very diminished. If it's a Truss rod issue perhaps over the next day or so the neck will settle back to where it was with the rounds originally? I suspect the tech that did my setup when I got the flats didn't move the neck. (He didn't think much of the TIs, incidentally!). Also the harmonic weirdness is completely gone. Interesting because when I fist swapped back to flats it was still there but these feel like they might be higher tension ( I seem to have a collection of old strings in my tool box!).

One of the things that came up through my recording sessions was that it's incredibly hard to get any high end out of the TI flats. I initially put them on partially out of curiosity but I ended up liking how they felt rather than how they sounded. Certainly they did sound quite dull on the recordings. I'd usually compensate with my amp but the engineer doing the recordings only wanted DI from me so he could take care of all the re-amping duties in his own time and place, which complicated things. It was successful eventually but I think a lot of mixing tricks were needed to make them sit properly in the track.

The stuff I was recording on was a mixture of Krautrock, Mellow proggy rock, Vaguely Eastern European sounding funky rock and 70s US funky theme tune material. In retrospect the TIs weren't probably the best tools for the job.

So long story short, I'm not convinced about recording with those TIs for anything other than straight up jazz. Does anyone have another experience with them?

[Ou7shined]

Oddly enough my 440Hz rattle is on a bass with TI flats too. I'm sure it's just a coincidence though.

I have a set going on a rattle free 70's P bass soon..... I'll keep an ear out.

[iBudd]

Well I believe in coincidences... but I don't trust them! That TI A string is only gauge 70. Light for an A string, I'd usually put an 80 on there... maybe the nut slot is the issue, not the depth but the width? Combined with the low tension..? More investigation necessary I feel...

[KiOgon]

[quote name='mercuryl' timestamp='1320277442' post='1424876']
Check out this video. Zoom through to about 3 min 38 secs. He gives some good info about how A strings commonly rattle. Do what he says and it'll probably fix it.

[media]http://www.youtube.com/watch?v=G5zUc6S4QV8[/media]
[/quote]
Great information video - but I wish he'd taken more care regarding the finish on the body around the bridge. Pulling the old strings off like that can do some terrible damage with the sharp ends. I always use a couple of business cards, 1 above & 1 below the bridge to prevent scratches.

[LiamPodmore]

[quote name='KiOgon' timestamp='1320321091' post='1425225']
Great information video - but I wish he'd taken more care regarding the finish on the body around the bridge. Pulling the old strings off like that can do some terrible damage with the sharp ends. I always use a couple of business cards, 1 above & 1 below the bridge to prevent scratches.
[/quote]

Same here, trying to pull a .130 or .135 B string through my Squier bridge is a b*tch and the ball end ALWAYS hits the body when i do, it just doesnt have the space to get through properly without doing it, quite annoying really.

Liam

[Noisyjon]

If you tap the back of the neck with your finger/knuckle around the 2nd fret area you will hear if the truss rod is knackered as it will rattle when you tap it, I had exactly that on my Bravewwod recently

[iBudd]

That's a nice tip Jon, fortunately no rattle here but that's a bummer about your Bravewood. Did you get it sorted? I've thought about getting a Bravewood before. I'll be 40 in a couple of years and I feel like I should get myself for my 40th birthday the bass I'll use for the rest of my life. Something nice from the Fender CS would be nice but I was thinking something genuinely custom built like a Bravewood too. Ah well, see how flush I am in a couple of years!

For those eagerly following the exciting story of my 440Hz rattle, now that I've got the rounds back on the bass everything feels a lot more stable and sounds better. The rattle is still there but I need to hit the open A very hard to produce it - plus it now sounds slightly brighter, much like the strings. This last point initially sounds kind of obvious but it at least means that the vibrating string is the culprit, rather than something loose somewhere, or even the nut... I'll let everything settle and do a proper setup when I get time.