Hex/Round Core Strings & Relationship to Tension/Stiffness

[overdrive]

Curious...given two identical string core diameters, one hex core & the other round core both with identical wrap thicknesses, why does the hex core tend to have more tension or feel a bit stiffer?

I noticed this but haven't a clue why (or where) the hex pattern affects this...always thought the hex pattern was simply utilized to maintain a tighter wrap.

[David Schwab]

I'm not sure about the reason, but the hex core has less material compared to a round core, since it's just the edges of the hex that come to the full diameter.

I would think that would mean the slightly thinner hex core would need more tension to get to the same pitch than the core with more mass.

[overdrive]

Thanks David...I looked into this topic a bit further & got some feedback from DR Strings. I've always found round core strings to be a tad easier to play with a slightly fuller tone. Here is their explanation & it makes sense to me.

According to DR:
Round core wires have more even contact with the windings. Imagine wrapping a piece of wire around a piece of round pipe. The wire, like the windings on guitar strings, contacts the pipe with equal pressure throughout the entire circumference of the pipe.

Now imagine wrapping a piece of wire around a rectangular piece of lumber, like a 2 x 4. The wrapped wire will 'dig in' to the square corners of the lumber. The wrapped wire contacts the 'flat' sides of the lumber with a lot less pressure.

Imagine the same thing happening with guitar strings. The outer windings, when wrapped around a hex shaped core, will contact the 'points' with more pressure than when they contact the 'flats'. But do the same thing on a round core wire and the contact pressure will be equal everywhere winding meets the core.

More evenly distributed pressure in the windings typically results in:

1 - Lower overall tension

Round core strings have lower tension than hex core strings. The perceived 'work' required to fret the strings is less with round core strings. If your fretting hand is bothered a bit by what you perceive as a lot of string tension, switching from hex cores to round cores will reduce that tension a bit.

2 - More sustain

Because all of the stresses of core to windings are more equally distributed, round core strings can use more of their physical energy to produce SOUND. Hex core strings produce more friction between the core and the winding. That means that some of the physical movement of the string is wasted in producing HEAT instead of SOUND.

3 - Even Harmonic Overtones

Like the difference in tube vs solid state amplifiers, round core wires emphasize the even or 'sweet sounding' harmonic overtones. This characteristic will be a little harder to sense than the other two above. But we can measure it on a spectrograph. The resulting tone is a little more 'bell like'. Consider that orchestral bells are made of tubular material. Vibraphone bars are made of rectangular material. A subtle but noticeable difference

The initial reason for my inquiry was that I was demo'ing some GHS EJ Boomers (hex core) after years of using the 'standard' round-core GHS Boomers. Aside from the nickel plated (over steel) wrap on the standard Boomers vs the all nickel hex core EJs & their slightly flatter wrap, the string tension difference between the two was noticeable & I actually preferred the cheaper, regular Boomers even though they don't last as long tonally.

[Mark Hammer]

There would be pros and cons to either type of core. certainly anyone using a wound string would like some assurance that the windings are equivalently distributed along the total length of the string (i.e, precisely the same number of turns around the core per unit of string length), and because of that extra grip, hex core provides greater assurances of that, and the intonation you would expect. Of course, as DR correctly notes,, you lose some string suppleness in the process.

[defaced]

One of the things I remember reading in some GHS (?) literature was about the core size to wrap size ratio. I wonder if they're different for a given gauge between the two core types? That would definitely make a difference in the feel, tension, timber - you know, everything.

[David Schwab]

I like the feel of the hex core D'Addario strings. I use 9's on guitar and 45's on bass, and with those gauges I prefer a string with a little more tension, especially on bass. I find they have a punchier tone. I have no problem bending those gauges.

I tried a few low tension strings and didn't like the feel for the way I play.

As far as more sustain on a round core, I don't buy it at all. That sounds like market speak. Less contact area on the core would mean less friction, not more.

DRs are OK strings, but I find them to be inconsistent, and when I tied them they didn't have a very long life. D'Addarios last forever, even with them being machine wound and with hex cores.

I used to use GHS Boomers on bass for many years, and not too long ago replaced a six month old set of D'Addario bass strings with a new set of Boomer, and the new strings sounded duller than the old strings! I took them off the next day.

I've tried just about every brand of string out there on guitar and bass over the years. I think the bottom line is find a string that sounds and feels good to you. There is no better string, just different. But some cheap strings do suck.

[jrfrond]

I'm not sure about the reason, but the hex core has less material compared to a round core, since it's just the edges of the hex that come to the full diameter.

I would think that would mean the slightly thinner hex core would need more tension to get to the same pitch than the core with more mass.

Possibly Dave. It really depends on the reference point as compared to round wire, i.e. the inside or outside of the hex.

I too agree that hex wire is stiffer, and my theory has always been that, due to wire profile, the apex' of each adjoining side act as stiffening bars.

BTW- I like D'Addario strings for all the same reasons. The hex core really keeps the windings tight and strings go dead less. I don't think I've EVER gotten one dead out of the package. Also, if you have toured the D'Addario factory like I have (they are local, and our Italian grandfathers were actually friends!), you will never see a more modern factory, or people dedicated to building/upgrading/modernizing application-specific machinery as they are.

[David Schwab]

I don't think I've EVER gotten one dead out of the package.

I got a dead D string from a bass set last year. I emailed them, they asked for the batch number from the strings, and sent me two replacement strings.

I've been wanting to visit the factory, since I'm not that far.

As far as the hex diameter... if the overal string is the same diameter, and the wraps are the same, then the inner core would be measured from the corners of the hex. The flat areas are missing mass compared to a round core.

Unless they squeeze the core into that shape of course!

On another example, I have a set of the half rounds on one of my basses. These start off as round wounds, and then are ground to make the surface semi flat. They are MUCH stiffer than the same gauge round wounds. So I'm assuming it's because they start with a heavier gauge or something. I'm not sure what's going on.

[jrfrond]

On another example, I have a set of the half rounds on one of my basses. These start off as round wounds, and then are ground to make the surface semi flat. They are MUCH stiffer than the same gauge round wounds. So I'm assuming it's because they start with a heavier gauge or something. I'm not sure what's going on.

They take stuff like that VERY seriously. I am not surprised. They are sticklers for perfection.

That is PRECISELY how Half-Rounds are made Dave, starting with a thicker string. However, part of good string-making is the relationship between the core gauge and windings. For instance, one of the reasons that their Chromes bass strings are so stiff is that they have a three-layer compound winding. They are a compound RW that is then wound with a stainless-steel ribbon winding. Pretty cool, and makes for a longer-lasting, brighter flat.

You should definitely head East and tour the factory. It's an education in itself. As a tangent, D'Addario Strings, and their adjacent Evans drum head operation, are totally autonomous. Even the packaging is printed and cut in-house.

[Bruce Johnson]

I'll also put in a good word for D'Addario. I've been using their Chromes flatwounds exclusively on all of my basses for about 12 years. I order them in bulk (144 sets at a time) in a special custom length. As a business, D'Addario are wonderful to deal with. Their prices are very reasonable, they complete orders and ship on time, and they rarely make a mistake. I've bought maybe 600 sets of bass strings from them over the years. During that time, I remember one bad A string, which had obviously gotten nicked in the outer wrap. And once I found a single D string in a bag of G's.

Like David said, string preference all depends on the design of the bass, how it's set up, and the players' technique. For the type of basses I build, and the style of music they're mostly used for, the Chromes are just right. A very warm tone, smooth surface, and stiff feel. The Chromes also last many years. Almost all of my customers are still on the original set shipped on the bass. On my own various basses, I've got sets that are almost 15 years old and still going strong. If the bass isn't played often, they will start to tarnish and lose some high end and sustain. But if maintained, they seem to last indefinitely.

In my own playing history of about 75 gigs and sessions per year, I think I've only replaced one string in a Chromes set. It was an A string that somehow got caught on something at a gig and broke the outer wrap.

[jrfrond]

Nice work Bruce!

As an old "P-Bass & Flats" fan, I can really appreciate what you are doing with the Ampeg design, and turning it into a multi-trick pony.

[Bruce Johnson]

Thanks, John! Yeah, I'm off in my own corner of the bass world...

One other note about D'Addario Chromes bass strings:
They have a break-in time. Right out of the package, the Chromes usually have a funny tinny overtone. I'm not sure what causes it. It could be a coating of protective oil, or the way the outer wrap is seated, or something else. But if you play them for a half hour and let them sit overnight, they start to sound better. A few hours of playing and a week, and they're pretty good. After a month, they sound beautiful and will stay that way for ten years. Maybe it just takes some finger grease and some corrosion to seat all the layers together.

D'Addario ships the bulk strings in sealed bags, but I always immediately open them and let them sit on the shelf exposed to the air. They may sit there for a month to two years before they get used or sold. This helps to reduce the break-in time.

In comparison, LaBella's flatwounds usually sound beautiful right out of the package, and stay that way. The LaBellas and the D'Addario Chromes are very close in tone and feel, once the Chromes are broken in.

I mention this because I think that's a big reason why you hear some players say that they tried Chromes and didn't like the tone. They probably didn't give them a chance, or tried a fresh set on a store instrument.

LaBella makes wonderful strings, but I long ago gave up trying to deal with the company out of frustration. I'm staying with D'Addario.

[jrfrond]

Bruce, not only did I notice that with Chromes, but with their Half-Rounds as well. Not quite sure what it is, and I never asked them. It is accompanied by a "grabby" feel on the surface of the string. Once it breaks in, yes, they last forever.

As long as we are on the topic of flats, my favorites are, ironically, Rotosound RS77LD Jazz Bass. They remind me a lot of the Chromes, without the break-in period, and have a definite, yet subtle "edge" in their tone. They sound great on maple FB basses for the 70's slap-funk vibe, but do fingerstyle well too.

[Bruce Johnson]

Yeah, I had Rotosound make up some RS77's for me in the special length, back around 1998. I call them Nasty Flats. They have a harsh twang in the upper mid range that can sound funky and cool on a P-bass type instrument. On my Scroll Basses, they were too much; too nasty.

GHS Brite Flats are up in the Nasty end of the spectrum, but not as much as the Rotosounds.

At the opposite end are Thomastiks, which I call Pillow Flats. The feel is very flexible and springy, and the tone is soft and dominated by the fundamental. They're great for getting a thumpy bottom end out of a bass that's normally twangy and harsh. On a bass that's designed for flatwounds, they're overkill. Too much fundamental and not enough of the rest of the range. To me, they feel rubbery and clumsy to pluck, but that's just my own preference.

That about covers flatwounds. There aren't too many choices. The business model for manufacturing them isn't too promising. Flatwound players are a small minority, and they only need strings when they buy another bass!

[jrfrond]

Y'know Bruce, you left out Fender flats, which are very old-school, being very flexible and thumpy. There's also the pricey Pyramid, standard on all German Hofners.

I can see why you don't like the RS77's on your basses. They aren't that vibe. However, on my Ibanez Roadstar RB650 that has a 1pc. maple neck, BadAss II and DiMarzio's, you can slap da sh*t outta them!

From what I have seen, flats are on the upswing again. Hey, I recently saw a Rick 4001 strung with flats! As hard as it is to believe, Ricks and even Alembics all originally came with flats (Alembic used Pyramid Gold).