My apologies for posting this twice, but I have not got all the ins and outs of the forum down. I apparently sent this as an unaswerable message:
Recently I had my guitar in for some minor work and the repair guy suggested that I string the guitar with normal tension strings. This was because the guitar was 40 years old and should not be subjected to the undue stress that might be caused by high tension strings.
I had not thought about this since the 1970's. At that point my guitar teacher told me to string the guitar with high tension strings and that's what I have always done, withou t giving it a second thought.
I took a spin around the web via Google and cannot find any advice beyond "do what you like." Then I joined this group:-)
So, the questions are "what's the difference?" Is the repair guy right? What strings do you use? Why? What is it supposed to affect? The sound? The playing?
I use normal tension strings on my Cordoba C5 (2007 - made in Portugal). It does have a full, 25.5" scale length, however - I have been advised that, if the scale length is much shorter, the normal tension can feel like "rubber bands".
The recommended strings for my C5 (at least for the current, Chinese-made one) are high-tension. But, since I've read in many places online that the C5 did have a tendency toward bridge-lift (especially the Portuguese-made ones), I last re-strung with normal tension - and I believe that it had normal tension strings on it beforehand. I received this guitar in March or so of this year...
I think the tone is great - I'm not sure what benefit, if any, high tension strings would provide over the normal tension ones...I'm sure someone else can fill us in... :-)
High tension strings are slightly thicker than normal, therefore slightly heavier and so they require more tension to get them up to standard pitch. The total load on the bridge with normal tension strings is about 84 lbs. +/-; the load with high tension strings is about 89 lbs. +/-, or about 6% higher load. The heavier high tension strings therefore deliver a little more energy into the bridge given the same playing effort. This may or may not make for brighter or more powerful sound, depending on the instrument. The feel of the strings under the fingers may be a little firmer or stiffer as well, especially with high action. So, ultimately, the sound and feel of the string/instrument combination are personal preference.
I have four 30-50 yr. old guitars, none of which have suffered damage from being strung with HT strings most of the time. However, if the bridge is "lifting", as FloridaGull noted below, or if it appears to be twisting - low in the front, high in the back - there is more tension on the face than the guitar is built to handle. In fact, going to lower tension strings may not be enough to solve the problem. There are low-tension strings that will put even less load on the face than normal strings, and these might be the best option. If this distortion of the face goes too far the guitar becomes unplayable or will require major repairs. Hope this helps. - Dave
See? I knew someone would fill us in... :-)
Richard - I can't add much to what the others have said; they did a great job. I would get a second opinion from a trusted repairman. Not all classicals come with adjustable truss rods and sometimes switching string tension can change the fretboard. You might also have to tinker with the saddle.
I prefer high tension, but that's just me. I've also found out that, with only a couple of exceptions, high tension strings are usually not really high tension so, as David says, they don't significantly increase the load on your guitar.
I know that my Cordoba C5 has no adjustable truss rod...
I want to thank all the posters to date. Some additional info that might be helpful, and which may explain why I asked the question.
My guitar is a Martin 00-18C. This was/is a very nice instrument which has the dubious distinction of being one of the few 40 year old Martin's that has NOT increased substantially in price ;-). Fortunately, I really like it and don't care what it is worth.
There is nothing whatsoever wrong with the guitar. The work I had done was to smooth a small rough spot on the bridge that was popping a string. The gentleman who did the work was/is certified by Martin to make factory repairs. The neck is straight and the body is not bending or warping in any way.
When I picked the guitar up from its repair he cautioned me about the tension of the str ings, and to be honest, I had just never thought about it. I had always used D'Addario high tension strings. So when I restrung it I picked up a set of normal tension strings and that was that.
Except that in my idle moments I had started to wonder about the why's and wherefore's of the advice. Which is when I posted my questions this morning.
Since it has been awhile since I have played regularly I think I will give a few sets of normal tension strings a try, and then when my ears can recognize what they sound like, I will restring it with high tensions and see if I can notice a difference.
I think almost all have already been said. I would add that tadtionnal classical guitars don't have any truss rod, because the lutherie doesn't require one. Some have like, mostly high-range guitars, made by manufacturers (Yamaha for instance on some models, but these aren't real classical, closer to hybrid) or high-class luthiers (who seek new technologies, so very expensive). Some traditionnal classical guitars though have a kind of reinforcement (hope this is the right term, sorry!) in the neck, which consists of a piece of ebony that looks like a thin dark line all along the neck. Similar to some steel-string acoustic or some electric guitars (Fender does that on some models). This feature makes a higher price, but still affordable : I've got an Esteve model 3 (solid spruce top model), which is a good study guitar, around € 550, with a simple, traditionnal neck. And I guess the first model including ebony 'bonus' inside the neck may cost around €700. In anyway, even with a simple lutherie, keep in mind that a descent classical should bear high string tension. But, in order to avoid any risk, keep in mind that the quality of the instrument is the key to the right choice of tension. I recommend normal or low tension if you have any doubt, or if you have a low range guitar. And then, if you want to go for high tension, for all reasons mentioned above, ask to the manufacturer, the luthier, or the retailer for further information. I guess even a good, high-end instrument is likely to bear one specific tension. On the other hand, I have some doubts on low-range guitars made in Asia (except reknown brands like Yamaha or Crafter for example). My Esteve was mounted with normal tension and I keep this one. The string brand, which is also a matter of personnal taste, can provide differences in string gauges for a given tension, and in feeling/comfort as well. Maybe you should contact string maker for advice. I personnally use D'Addario Pro Artes normal tension (EJ45 reference). They've got a well-built website with information about gauges, tensions etc, and they also answer to any question. I guess it's the same for all string makers, so you should contact the guys of your brand. Also, there is a luthier in California who could inform you (I contacted him when I was looking for a classical guitar, in order to get info about lutherie). Here's his website:
Last thing : soon I'll see a luthier to have my Esteve set up by a luthier, in order to make it better with my own play (nuts changed for bone ones, frets and lower action setup). I could ask him about string tension when I see him.
Richard - We've all been so busy writing about all the technical aspects, truss rods, etc. that I'm afraid I negelected the last part of your real question: The sound? The playing?
This gets into personal preference. I will use whatever sounds best on my guitars. One of my classicals uses hard tension while the other two use mediums. The one that uses higher tension has an adjustable truss rod (Kenny Hill); the other two don't. The Hill guitar was built with hard tension in mind and I like the firmer feel and quick response of the hard tensions. I believe I also get a clearer, more evenly distributed sound.
The other two (one a Lower end model Yamaha; the other a high end Ramirez) were built for mediums and do not have adjustable truss rods (Note: I tend to refer to any reinforcement system as a truss rod, as opposed to an ajdustable one, but this is misleading - as Pascal pointed out. Most modern classical guitars don't have adjustable truss rods, but the better ones do have some sort of reinforcement. My Ramirez has that beautiful black ebony stripe down the back of the neck which serves to reinforce it). Personally, I'd be cautious of capriciously changing tension if a guitar did not have some sort of reinforcement. Though I balked at the idea at first, my Hill guitar's adjustable truss rod is really a good way to go and more makers are using them these days.
The mediums are easy to play. I believe a little volume is lost and they are suseptible to unwanted bending (out of pitch) while also not being able to handle rough playing.
As I said, to each guitar her own. My Hill has a european spruce top; my Ramirez has a cedar top. Personally, I like the HT for spruce and the mediums for cedar. Spruce is harder to move air with while the cedar is easily resonant and the tone seems to come out from an unidentifiable source (seems to be everywhere in the room... real presence). Beautiful sound.
At the risk of going back to "Do what you like," without seeing your guitar I can't say for sure but I'd take her to get a second opinion. If it's doable, I'd try each on your guitar and go with the one you like, realizing you will most likely have to do some sort of re-set to the action.
Have we confused you enough?
Many great comments here , so I have probaby little to add apart from subjective experiences. I have two 'classical' guitars. One is almost 50 years old and was made by a luthier in Perth, Western Australia. It has a longer than average scale length, so I find that light tension strings suit it (and me!). More give for my fingers and quite a nice mellow tone. I have tried medium tension strings, however far too hard and sounds 'tinny'. The other one, an Esteve, feels better with medium tension. I bought it with high tension strings, but I was not over happy. The esteve is a smaller scale length than the De Jager (the other one). Anyway , I quite like experimenting with the types an brands of string. Its is always a bit exciting in the lead up to playing a re-strung guitar! There is occasional disappointment.......but thats ok. In that way I can work out the better strings to use. Also, I would probably change my strings every three to four months.
Here are some things I learned about classic guitars:
First, a good cedar neck doesn't need any kind of truss rod or reinforcement. Cedar is lightweight, and very stable. Besides, the string tension in a classic guitar is very moderate. D'Addario Pro Arté Normal Tension strings have a total tension of 83.6 Lbs/37.73Kgs. Heavy gauge strings may add about 3-4Lbs/1.5-2.00Kgs more - and that won't affect a good neck, made of good, well dried cedar.
Fingerboards are totally different, because rosewood or ebony, though much harder and heavier, are not as stable as cedar. Besides, fingerboards are not varnished, so they absorb, or lose, humidity. I always monitorize fingerboard planks for months before gluing them to the neck. If a fingerboard plank is dead straight in summer, it will probably bend in winter. That can be neutralized with a plane, and with the right choice of what face to glue against the neck. But I doubt guitar factories can afford that kind of care and attention to each part of a guitar. At the very best, they will choose the most esthetically pleasant face and glue the other face to the neck (thus, the instrument will sell easier) ... so, my guess is that, in most cases, a bent classic guitar neck may not be due to string tension but to poor woods, poor wood drying or inconsiderate positioning of the parts at the moment of gluing... and it would bend regardless of string gauge.
Second: The bridge area is much weaker. Top may be 2.5 milimeters thick at that area and the fan bracing under it is made of seven triangle-section spruce braces with 3.5 milimeter wide sides. That's why tops may get concave in front of the bridge and hump between the bridge ant the tailblock (bottom). That will cause bridge-lift. You may compensate that, to a certain point, with a lower nut, but there are limits. Heavy gauge strings may in fact make a difference. I usually string my classic guitars with normal gauge strings (d'Addario). I only string them with heavy gauge strings for special purposes (say, to record), and only for a few days. Action will not change in a short term. In a long term, however, the top will respond to the increased tension and a lower bridge nut may be required. I believe the crucial issue is how the guitar was made. If, at the moment of gluing, the braces were forced against the top in a concave solera, the top will hold string tension (even that of heavy gauge strings) much better.
Third: The reason why people usually tend to use heavy gauge strings is to get more volume and brillant tone. However, that can be achieved with normal gauge strings if you get a proper bridge nut installed by a pro. It is crucial that the nut fits precisely the bottom of the bridge slot, but it is also important that the nut fits the slot sides. It must fit them in a way that it is difficult to remove it with bare hands. However, if it is too tight, it can break the bridge. It is also important to have the proper string angle over the nut. And the nut must not be crest-shaped, it should be rounded backwards to allow a good string-nut contact . If the nut meets these requirements, the sound quality of the instrument will increase a lot.
Fourth: Classic guitar players usually go for moderately high action. So, it's only natural that teachers recommend heavy gauge strings. They ususlly follow classic set-up. I personally prefer low action, almost flamenco-like, even if I risk some minor buzzes...
The above picture shows the gluing of a 5-brace fan bracing: the solera is inside a go-bar deck, go-bars press the braces against the top; but the top itself is being pressed against the concavity of the solera. When glue dries, top is permanently dome-shaped, thus resisting string tension. I guess this is not how they make it in factories... (notice that, at this time, braces have square section; only after glue is dry they will be chiseled to final triangular section).
In this last picture of another guitar, we may see the bridge area at its final condition, featuring the "magic" fan bracing. I made this guitar in 2009. It was first strung with normal tension strings and, a year ago, the owner strung it with heavy gauge strings.
I have a Cordoba 55R. A couple of days before going to the studio to record I changed the strings. I'd used Augustine Blue on all the other classical guitars I had ever owned so that's what I used. It was a disaster.
The intonation was all wrong. A tenth fret third string E did not match the open 1st string E. All open strings sounded in tune. My producer and I could not figure out what was wrong. I took the guitar home and messed around with it. I found the harmonics at the twelfth fret and the fretted notes at the twelfth fret did not match. I wrote Cordoba.
After a little research I found that the guitar came with Savarez high tension strings. I drove an hour each way to get these and putting them on solved the problem.
A couple days later I received a response from Cordoba that confirmed intonation problems are generally string related. I can say the regular tension strings felt easy to play. Generally I'd like a little easier action, but not at this expense.
Every time you press a string to get a fretted note, the string tension increases a little ( you need to bend the string downwards, and that means increasing the tension). High tension strings take a little more pressure to be fretted, so the increase in tension is bigger. Besides that, higher tension means a little higher action. So, that also means a little more tension increase when they're fretted. Adding those little increases, you may get a noticeable loss of accuracy. It gets worse as you go down the fretboard: you won't notice it at, say, 5th fret, but you will notice it at 12th fret. That's probably why your 3rd string 10th fret E didn't sound like the open 1st string E. To compensate that, you may replace the bridge nut: if fretted notes sound higher than they should, you must install a lower nut, and vice-versa. In extreme cases, you may always sculpt the nut's crest in order to gain (or lose) about 1 milimeter in string length.