Harmonics out of tune on different string types/brands?

Android Entropy · #1 08-24-2010, 10:35 PM

OK, I did quick search and this issue didn't pop out. It is one that I've noticed off and on over the years, lately it has become a much bigger issue for me.

Here's the thing. After playing a mixture of fretted and fretless over the years, I've really been concentrating on fretless lately. I've been experimenting with various string types. I've ended up playing half rounds for various playability issues (which I've recently solved), and have been getting a really good sound, but I've missed the brightness of roundwounds for certain styles.

So I recently put roundwounds back on one fretless bass, and playing it, I can't help noticing that the notes sound "sour" up the neck, especially on the E and A string. It sounds like the harmonics are out of tune with the fundamental. This isn't the first time I've noticed this with roundwounds (on fretted basses as well as fretless), but after playing the half-rounds which don't seem to do it as much, I'm really bugged by it, especially on fretless which is more lyrical.

I experimented swapping around strings and basses, and the effect seems to be associated with the string, not the bass. I don't have a bunch of different brand strings and types lying around, so I can't say much beyond that. (this experimentation could get expensive!)

Is this is a issue that people are sensitive to? Have folks experienced this phenomenon with either roundwounds in general or particular brands? Is it possible that this effect will go away after the strings have worn in a bit?

I'd really like to get the brightness of roundwounds (although they are a bit brittle for the first few days) without the sour-up-the-neck-on-the fat-strings effect. Have others struggled with this and found a solution? Understanding it is the first step.

Any help would be greatly appreciated! This one has me scratching my head.

Kael · #2 08-24-2010, 10:39 PM

I take it that it is a safe assumption that you've reset the intonation after each string change?

Android Entropy · #3 08-24-2010, 10:55 PM

This is not an issue of the pitch of the fundamental. If I couldn't hear and compensate for that, I wouldn't be able to play fretless worth a damn. And yes, I reset the bridge whenever it sounds wrong, not just at string changes (although that is usually when it's needed).

It's just that the upper harmonics sound out of tune with the lower harmonics. I can hear it on a fretted bass I've got too. If you listen closely above about B on the E string, the string sounds "out of tune with itself". I've always thought that this was just an effect of string thickness/rigidity, but if so, then why don't the (D'addrario or Ken Smith) half rounds also do it? Because they have fewer harmonics to listen to? Maybe, but my ears aren't buying that theory yet.

Maybe it is just the brand of roundwounds, or that they are new. But I'm hearing it on two different brands (GHS boomers, LaBella slappers).

David1234 · #4 08-24-2010, 11:23 PM

The stiffness of the string is sometimes a factor, and taper strings (where the string is narrower where it passes the bridge saddle) can reduce this.

Also, some claim that magnetic pull from the pickups is a factor, so some pickups like those on the Fender Roscoe Beck basses use a wider, less intense magnetic field on those strings. You could experiment by moving the pups further from the strings and see if it's more pleasing to your ear. I think Warwick's "dynamic correction" pickups have a similar claim (but I'm not 100% certain). Certainly the Roscoe Beck basses I've played sound good in the high register even on the E and B strings, where other basses would lose definition on notes from that part of the neck.

**bassybill** · #5 08-25-2010, 01:09 AM

Dr. Bill is going to stick his neck out here and diagnose this as a possible case of stratitis (so David is on the right track here).

That comment about "the string being out of tune with itself" in post #3 is an almost certain indicator, especially as the effect seems more apparent on the E string. Check this out:

http://www.riograndepickups.com/faq.htm

I'm sure it's entirely possible that this is more noticeable with some strings than with others.

Quick test you can try - check for the effect unplugged. Then plug in, but with your volume on the amp turned all the way down and check again. Is it more noticeable at all? If it is, then it's due to the magnetic pull of the pickups on the string (this pull is greater when plugged in and current flows through the pickup coils, owing to a physical effect described by Lenz's law).

The usual solution is to increase the distance between the pickup and the string very slightly, especially for pickups nearer to the middle of the string and at the end of the pickup under the heavier gauge strings. On a four string Jazz bass, for example, the effect would be most noticeable with the neck pickup when playing middle to high positions on the E string, and least noticable with the bridge pickup when playing in lower positions on the G string. Increasing the distance between the neck pickup and the strings on the E/A side would probably eliminate this effect if this is indeed the cause.

ggunn · #6 08-25-2010, 04:06 PM

Quote:

Originally Posted by bassybill

Quick test you can try - check for the effect unplugged. Then plug in, but with your volume on the amp turned all the way down and check again. Is it more noticeable at all? If it is, then it's due to the magnetic pull of the pickups on the string (this pull is greater when plugged in and current flows through the pickup coils, owing to a physical effect described by Lenz's law).

Are you sure about that? The amount of current flowing through the pickup is very, very small. The magnetic field it induces has got to be minuscule compared to the field strength of the permanent magnets in the pickups. I'm no physicist, but this doesn't sound reasonable to me.

BTW, I have experienced Stratitis (on my Strat), and the effect was there whether or not it was plugged in to an amp.

Android Entropy · #7 08-25-2010, 09:56 PM

OK, I'm calming down a bit. After a bit of wearing in, the out-of-tune-with-itself effect is diminishing on the Boomers. They still sound funky (not in a good way) above the octave on the E string, but things are much better below the octave after some aggressive break-in on the strings.

It's been a while since I played round wounds, and since I've been playing exclusively fretless, I'm very sensitive to intonation issues. I'm beginning to suspect that what folks refer to as new round wounds being "too bright" is actually this out-of-tune-with-itself effect that I'm experiencing. Time will tell - I'm giving these strings a few more days to wear in before I get frustrated.

It's funny. Way too many years ago when I started playing, I thought new (roundwound) strings sounded fantastic. Later I remember thinking they sounded good new, but better after about a week. Now I think they sound CRAPPY new, probably better in a couple weeks, but time will tell.

I'll report back.

- Andy

P.S. I don't think this has anything to do with the magnets in the pickups affecting string vibration. And since I'm an electronic engineer, I can say definitively that plugging in the bass makes absolutely no difference to the current that flows through the pickups. I do believe that with thin strings (guitar, not bass), strong magnets, and with pickups very close to the strings, that "stratitis" can occur. But unless your pickups are way too close to the strings, I've never seen this be a real effect with basses. But then I've never used some of the "massive magnet" pickups out there - though I'd like to try just for fun.

walterw · #8 08-25-2010, 10:14 PM

warble from pickup magnet pull is a very real thing, especially on high frets on the low (i.e., big and loose) strings. i'm skeptical of there being a big difference with plugging them in, though, they're not generating that much current to where significant back-force is being created.

the other thing to look for is the seating at the witness points. if the string hits the saddle, then curves up towards the middle of its length before straightening out, weirdness like this can happen. be sure to press firmly at each witness point (at both ends) so that the string is perfectly straight along its vibrating length.

also, if the string gets twisted as it's being wound on, it can misbehave. after the first few winds around the key (while there's still a little bit of string slack), push the ball end out of the bridge a little so that the string can spin freely and un-twist itself.

Android Entropy · #9 08-25-2010, 10:50 PM

Great tips, Walter! Thank you! I never thought to untwist the ball end after winding.

On the magnet warbling - if that is what is going on, why would the effect be greater with round-wounds than half-rounds? Also, I've got another fretless with EMGs (advertised not to have this magnet effect), and the pickups are not particularly close to the strings, and I get the same effect.

- Andy

walterw · #10 08-26-2010, 08:28 AM

well, half-rounds are going to have less of those upper harmonics, so you'd hear less effect.

emgs have no pull to speak of, so whatever's going on in that case, it isn't magnet pull.

ixlramp · #11 08-26-2010, 01:54 PM

Inharmonicity can occur with a taperwound string when the length of tapered segment in the scale length is a significant proportion of the scale length. The tapered segment should be roughly less than 1/2 inch, and ideally as small as possible, but is usually 1 inch or more because manufacturers want their strings to be usable on many different bridge designs, which have many different saddle to ball-end-anchor-point distances, for example string-thru- body.

The less a string is of constant gauge from nut to saddle, the less it vibrates harmonically.

Therefore the amount of tapering is important too, exposed core taper is more inharmonic than taperwound. The thinner the tapered section, the more inharmonic.

http://circlekstrings.com/store/index.html design their strings with a shorter tapered section than usual for more harmonic vibration. Their strings are also more flexible than most since stiffness also causes inharmonicity.

Thunderthumbs73 · #12 08-26-2010, 02:00 PM

Good thread. This is the GOOD kind of bass-related minutiae. I feel like I'm learning something here.

ixlramp · #13 08-26-2010, 03:34 PM

Quote:

Originally Posted by Android Entropy

If you listen closely above about B on the E string, the string sounds "out of tune with itself". I've always thought that this was just an effect of string thickness/rigidity, but if so, then why don't the (D'addrario or Ken Smith) half rounds also do it?

It is a result of string thickness and rigidity, but also flexibility varies between brands. D'Addario Prosteels are the most flexible I've discovered, perhaps their half rounds are super flexible too. Apparently Circle K are the most flexible in existence, they make E strings with 2 layers of wrap! Elites are the stiffest I've discovered.

As you play up the neck on a fat string, it's width in proportion to it's length increaeses rapidly, making it effectively stiffer, increasing inharmonicity.

The D'Addario Prosteel tapered .145 is an amazingly harmonic string for it's gauge. The tapered section is .085, well over half of it's full gauge, so even with 1 inch of taper in the vibrating length the taper does not produce much inharmonicity. Also, it has 3 layers of wrap instead of 4, making it more flexible.

If you're playing fretless I can recommend D'Addario XL Nickel roundwound, they're brighter than half-rounds but still have a smooth nickel-plated surface to reduce fingerboard wear.

D'Addario prosteels are brighter but have a rough surface to them, not good for slides or for your 'board.

Even smoother are D'Addario EXP coated nickel roundwound, but still with a bright tone. They were on my new fretless when it arrived. Amazingly slippery for a roundwound.

**bassybill** · #14 08-26-2010, 11:00 PM

Quote:

Originally Posted by Android Entropy

And since I'm an electronic engineer, I can say definitively that plugging in the bass makes absolutely no difference to the current that flows through the pickups.

Zero current flows through your pickups when the bass is not plugged in.

walterw · #15 08-27-2010, 04:35 PM

Quote:

Originally Posted by bassybill

Zero current flows through your pickups when the bass is not plugged in.

and, i suspect, not much more than zero when it is.

**bassybill** · #16 08-27-2010, 04:47 PM

Quote:

Originally Posted by walterw

and, i suspect, not much more than zero when it is.

It's an increase of infinite per cent - if you think about it.

I'm not even going to attempt to calculate it, though, or the increased force acting on the string when it flows. Although it's certainly true that both of these would not be zero, I suspect you're absolutely right when you say these values would be pretty small.

But I remember one guitarist telling me that the effect became much more noticeable on his instrument when plugged in. I don't know how big a force would need to act on the string to audibly affect this.

ggunn · #17 08-27-2010, 06:13 PM

I, too, have noticed that frequently when I put on new strings they sound sort of "clangy" to me, like (as you say) some harmonics are out of tune with the rest. Eventually they settle in and sound fine.

I have just recently learned to set the witness point when I change strings; when I changed to a stiffer string, I couldn't get the B string saddle back far enough to set the intonation, but when I bent the string sharply over the saddle, the problem went away. It was because the string was resisting the bend over the saddle and "thought" that the saddle was closer to the bridge than it really was. I discovered this on my own only to find out that it is old news to all you more experienced players.

But anyway, I wonder if there is a connection.

Since before setting the witness point the string is not seated tightly on the bridge and vibrates from a point somewhat away from the saddle, I wonder if the position of that virtual witness point is frequency related. It seems reasonable that lower frequencies could experience a node closer to the actual bridge saddle than higher ones when the string is in that state. That would perhaps explain the "clangy" sound of the string as well as the fact that it eventually goes away as the string gradually conforms to the bridge saddle as I play.

Whaddya think? Or is this, too, old news?

foundation · #18 08-29-2010, 09:26 AM

I'm a novice bass player,

but have found this thread fascinating. My new bass came with steel strings, and I've been struggling with a great deal of "humm", or resonance when I release a string. I'm completely willing to concede that this is due to poor technique, so I have been spending hours practicing keeping my fingers perpendicular to the strings both with the attack, and more importantly, the release as that seems to be where the string noise is coming from. Great attention to dampening as well. I did not experience this problem with my other bass, and I'm wondering if my technique (or rather lack thereof), combined with the huge tone and sustain of my new neck-through bass are the problem, and/or whether the greater "grab" of the stainless strings is contributing to this effect. Would nickel strings or half-rounds make things a little easier for me? Part of me wants to stick with stainless because I feel it is making me play more precisely, but in the meantime, I'm struggling. A local luthier also suggested lowering the "crazy high" bridge pickup a bit too. It is calming down a bit either through better technique, or with some wearing in of the strings, or a combination of the two, but it's a challenge for sure. Thanks.

fullrangebass · #19 08-29-2010, 09:45 AM

Quote:

Originally Posted by bassybill

It's an increase of infinite per cent - if you think about it.

....

But I remember one guitarist telling me that the effect became much more noticeable on his instrument when plugged in. I don't know how big a force would need to act on the string to audibly affect this.

Could the guitar player be hearing the amplified issue clearly (plugged in = the amp is on too, most of the times at least

) and NOT that the un-amplified issue was getting worse, just by the cable being plugged in??? (hope it makes sense)

ggunn · #20 08-29-2010, 11:19 AM

Quote:

Originally Posted by foundation

I'm a novice bass player,

but have found this thread fascinating. My new bass came with steel strings, and I've been struggling with a great deal of "humm", or resonance when I release a string. I'm completely willing to concede that this is due to poor technique, so I have been spending hours practicing keeping my fingers perpendicular to the strings both with the attack, and more importantly, the release as that seems to be where the string noise is coming from. Great attention to dampening as well. I did not experience this problem with my other bass, and I'm wondering if my technique (or rather lack thereof), combined with the huge tone and sustain of my new neck-through bass are the problem, and/or whether the greater "grab" of the stainless strings is contributing to this effect. Would nickel strings or half-rounds make things a little easier for me? Part of me wants to stick with stainless because I feel it is making me play more precisely, but in the meantime, I'm struggling. A local luthier also suggested lowering the "crazy high" bridge pickup a bit too. It is calming down a bit either through better technique, or with some wearing in of the strings, or a combination of the two, but it's a challenge for sure. Thanks.

Having to constantly mute unplayed open strings was a surprise to me when I started playing bass; I never had to worry about it too much on guitar. Some basses are more prone to it than others, but with all basses, all strings, you have to pay attention to vibrations in the instrument exciting open strings, especially the ones below (in pitch) to the string you are playing on.