FAQs – Mandolin Strings

Frequently Asked Questions, Straight Up Strings for Mandolins.

Siminoff – June 11, 2014

Q: I don’t understand the difference between download and string tension. Can you explain?

A: Tension is a lengthwise or “longitudinal” measurement whereas download is a sideway or “lateral” measurement. When a string is brought up to pitch, the tightening of the string exerts a pulling force at both the peghead and the tailpiece, and this force can be measured in pounds. This is the “tension” of the string and is measured when the string is up to pitch. On a movable-bridge instrument (mandolin, banjo, jazz guitar, violin) the string lays over the bridge and exerts a downward force through the bridge to the soundboard. This lateral or downward force is the “download” and it is also measured in pounds. For movable bridge instruments, the download is the important component to manage. (For fixed bridge instruments such as steel string acoustic guitars, the longitudinal tension is the important component.)

Q: Your gauges appear okay but the tensions don’t appear to stack up compared to something like D’Addario J75s. They claim to be 25, 23, 21, and 26 pounds from E to G.

A: There are two different measurements to consider: the longitudinal tension or pull of the string, and the lateral download – the pressure of the string pushing down on the bridge – and we do report both. For a movable bridge instrument such as the mandolin or banjo, the download at the bridge is a more important consideration than the longitudinal tension, especially where strings are positioned over bridge feet compared to being over spaces or arches in the bridge. The measurements we provide for our mandolin strings are the download at the bridge measured at a 16° string break angle (the angle the strings make as they pass over the bridge). The total download for our #2500 medium gauge mandolin Straight Up String set is 40 pounds, and the total longitudinal tension is 179 pounds. (By comparison, the J75 set you refer to has a total longitudinal tension of 190 pounds: [25+23+21+26] x 2 = 190).

Q: How can your .024˝ string be different from a GHS .024˝? Doesn’t .024˝ really mean .024˝? I thought gauges are gauges.

A: The outside measurement or “gauge” of the string doesn’t tell the whole story. Wound strings (D and G) – those with a “wrap wire” covering the core wire can be prepared several different ways. For example, the .024˝ wound string you are referring to could be made with a .012˝ core wire and a .006˝ wrap wire (.012˝ plus .006˝ twice [since the wrap wire goes around the core, it has to be counted twice] equals .024˝). You can also prepare one with a .014˝ core wire and a .005˝ wrap wire (.014˝ + .005˝ + .005˝ = .024˝), and so on. Each of these combinations presents a different longitudinal tension and download when the string is brought up to the same pitch. (There are also practical limits of too thick or too thin a core/wrap wire combination, but that goes beyond the scope of this question.)

Q: Did you use electronics or musical instruments to do your tests?

A: The only electronic instrument we used was a decibelometer to measure amplitude (loudness). Electronic instruments don’t really speak to the quality and timbre of the tones produced and it is difficult to relate that data to the human perception of tone. All other tests were evaluated by ear with several musician listeners providing input. The initial tests in our shop were conducted on several high-level mandolins that included: a Loar-signed F5 mandolin, three early Gibson F5Ls (an original 1978 Gibson prototype, an F5L from 1979, and an F5L from 1980), a Siminoff F5, and a Kali F5. Testing by other musicians was conducted on instruments of various makes.

Q: Are your Straight Up Strings round core or hex core?

A: The E and A strings are “plain” round core, and the D and G are hex core covered with a phosphor bronze wrap wire.

Q: How did you measure the down load pressures you are reporting?

A: We have a special fixture that measures any scale length between 26˝ (banjo or guitar) and 13-7/8˝ (mandolin). The fixture has a tailpiece at one end and various tuning machines at the other. The strings pass over a surrogate bridge that is suspended from a certified Dillion Force Gauge that can accurately measure the pressure in 0.5 pound increments. Our fixture can be set to any “bridge height” so that the down pressure is measured at any string-break angle. For our tests, we used 16° string break angle since this is the most common (and correct) angle for an F5 or A5 with a 5.5° to 6° neck pitch. We can measure single strings, string pairs, or all eight at once. Down pressure can also be calculated mathematically (sine/cosine), but we prefer to be able to monitor the changes in tension as the string is brought up to pitch. For more on string break angles please visit:  siminoff.net/string-break-angle-loads/

Q: Wouldn’t it be better if all the string tensions were the same?

A: In some cases, yes. If we were preparing strings for a fixed-bridge steel string acoustic guitar, then we would want the longitudinal tensions to be very similar, if not exactly the same.  And, we’d have similar tensions for mandolins that use a one-footed solid bridge, such as on the early Gibson models (A2, F4, etc.). But for mandolins that have the two-footed adjustable bridge, the down loads need to be adjusted for the string pairs near the posts and the string pairs that are suspended in the middle of the bridge’s saddle.

Q: I’m just curious; what kind of steel are your strings made of?

A: The wire industry refers to this type of semi-elastic wire as “mandolin wire.” And it is interesting to note that “mandolin wire” is also used for mandolins, mandolas, banjos, guitars, resophonic guitars, dulcimers, and similar instruments that use steel strings. In the wire industry, wire of this type that is smaller than .050˝ is called “mandolin wire” and wire of this type larger than .050˝ diameter is called “piano wire.”

Q: I thought gauges and tensions were totally related to each other. If that’s true, how can you make strings of the same gauge that have different tensions?

A: Gauges and longitudinal tensions are related to each other but since wound strings can be prepared several ways not every .024˝ string, for example, has the same tension as the same outside diameter wire prepared with another combination of core and wrap wire. Change the combination of core-to-wrap wire and you change the longitudinal tension at the same pitch.

Q: Doesn’t what you call the “download” change with bridge height? I would think that a taller bridge would create more pressure.

A: Yes, it absolutely does. If you first envision that a bridge could be so low that the strings basically pass straight over it, there would be zero download. As the bridge height increases, the download increases. At about a 16° string break angle (which is what most F5 and A5 mandolins have), the average set of mandolin strings pushes down on the soundboard with a load of about 40-44 pounds, and this is typically the sweet spot for most mandolins.

Q: The heavy E and light G are pretty unusual. How did you do the testing and come up with the gauges you have?

A: Straight Up Strings are designed to compensate for a structural weakness in the design of the Gibson two-post adjustable bridge which, by necessity, has two courses of strings (E & G) very close to the posts (with a rather direct access to the soundboard) and two courses of strings (A & D) in the middle of the saddle (a more flexible area with less direct access to the soundboard). Our goal was to balance the response from these strings by measuring the download on the bridge for each string, and then determine the gauges as a result of that test. So, a more precise answer is that in our ultimate tests we didn’t consider the gauges but focused instead on balancing the downloads. The gauges were just a result of the tests. It was a lot of testing of various gauges and core-to-wrap wire combinations, but in the end it was well worth it!

Q: I have an original F4 with a solid bridge, not the adjustable kind. Will your new strings work on my mandolin?

A: Yes they will work, but the advantage will not be as significant on your one-piece bridge as on a Gibson-style adjustable bridge. Straight Up Strings were designed specifically to compensate for the imbalance caused by the location of the four string courses (pairs) on a two-post adjustable bridge, where two courses are located close to the posts and two courses are located in the center of the somewhat resilient saddle. Your solid one-piece bridge requires strings with more similar down loads.

Q: How similar is the phosphor bronze on Straight Up Strings to the D’Addario J74 phosphor bronze?

A: There are only a very few manufacturers of phosphor bronze wire used for musical strings. Our phosphor bronze wrap wire is the identical type of phosphor bronze wire used on D’Addario J74 and J75 strings.

Q: Two questions: do you make these strings in yourselves, and if not, are they made in the United States?

A: Straight Up Strings are made to our specifications in the United States by a prominent string manufacturer.

Q: Do your Straight Up Strings have a longer life?

A: As previously mentioned, our strings are made of a semi-elastic steel wire that stretches something like, but not as easily as, a rubber band. You may notice that as you put on new strings, you keep tightening the knob to bring the string up to pitch. By doing so, you are not just tightening the string, but stretching it as well (proven by the fact that the string post is turning and winding on additional string as the string stretches). The elasticity gives the string brightness and richness. Over time and with usage and tuning, the wire’s elastic attribute diminishes and the string loses its warmth and richness. Our mandolin wire is the same material found in leading brands, and its life cycle is virtually the same. (It may surprise you to know that the plain E string on a guitar stretches about 3/16˝ when it is brought up to pitch.)