No judgement here.  Everyone has a preference to suit their own playing style and their own needs.  There's probably a way to measure the amount of tension on each string precisely, but that's not really necessary.  Obviously, the string tension has to lie somewhere between the minimum amount of tension necessary to produce a clear sound (without rattling) and the amount of tension required to break the string.  My own preference is for a string with some flexibility.  One that responds to hammer-ons, pull-offs, bends, chord playing, etc. with ease.  However, I fully understand why some desire less flexibility when playing noter-drone style.  It's all a matter of what "feels right" to the individual with the instrument in their hands.    

I'm probably the odd man out here. I hate the feel of loose feeling strings. If I'm chording 15# tension feels ok but playing noter/drone I prefer 17-20# tension. 
But I also have different dulcimers for different tunings so the string tension stays pretty much the same on all of them.

Oh Wow, what a great discussion.  I'm going to try the lower on some of the other duclimers.  And I've found that I really do like ONLY 3 STRINGS.  I'm so grateful for all I learn on this site.  Aloha, Irene

Jean never talked about lowering string pressure for anything... I don't believe she even thought in that way.  Since she played noter & drone with a pick, the effects of string pressure just weren't all that important.  Many of the olde time dulcimers had VERY high actions by modern 'soft finger' standards.  

As I've added more dulcimers to my collection, I've begun to label the cases with the tuning that seems to fit that instrument best.  My standard dulcimers tend be tuned to D-A-A, C-G-G, or sometimes even Bb-F-F.  My criteria for selecting the tuning is usually based upon string tension.  In other words, I change strings or tuning to get the "feel" I like.

I've also discovered that my reproduction dulcimers sometimes require a lower tuning to prevent the wooden tuning pegs from slipping under the increased string tension of the higher tuning.

John K.,

I remember reading that Jean Ritchie preferred C-G-G tuning.  I think her instruction book used C-G-G tuning.  But did she ever talk about lowering the tuning to make the strings more responsive to the touch of her fingers?   I suspect her choice of C tuning was likely based upon what was considered traditional in her family.

Ken H,

Good point.  I also tune down on occasion to better suit my voice.  Although a noter wouldn't give the same "feel" as the fingers, it would be similarly affected by string tension.  I suspect requiring less downward pressure on the noter would result in smoother playing.

Dusty,

I hadn't considered that string tension might have the opposite affect when flatpicking.  More tension = Faster Response.  Less Tension = Slower Response.

kjb,

Do you ever tune to a C tuning because it feels more comfortable on the fingers or only when playing with other musicians in the Key of C?  Do you prefer the lower tuning for fingerpicking because it is more responsive to the fingers?

I often tune to CGC so I can play in C with other instruments.  Also like it for fingerpicking. 

I regularly tune to C or C# when I fingerpick.  I don't use fingerpicks, but just my bare fingers, and I like the extra "give" in the strings. 

However, when I flatpick I want the strings very taught, as any extra give means the note is sounding slightly later than when you pluck it since the string bends before it makes any noise.  In other words, its harder to flatpick fast and accurately with looser strings.  So for flatpicking I tune to D and move my picking hand back towards the bridge or even tune up to D# or E.

I guess what I'm saying is that looser strings provide greater right-hand control when playing with fingertips but less control when playing with a pick.  So I adjust my tuning and my playing accordingly.

These days I play mostly in C --- Cgg or Ccc as the key of C fits my voice better.  Playing with a noter, the string tension is quite as important as it is for tender finger players.  I find that your ordinary D string set can usually go down to B without being too floppy, and up to E and maybe F for they get tight enough to break a bass string.

Greg,

You remember that Jean Ritchie used to play in the key of C a lot of the time?

Me too.

Obviously, the dulcimer can be tuned up or down to play in alternate keys, but what about adjusting string tension for comfort?

I've been noticing lately that I have a preference for less string tension.  Both my left hand and my right hand seem to be more comfortable when the strings are more flexible and have more give.  In practice, this means I frequently lower the tuning as much as a whole step to create the fingering sensation that I prefer.

Instead of the standard D-A-A or D-A-d tunings, I find myself lowering the tuning to C-G-G or C-G-c.  Obviously, I have to tune back up if I plan to play music with others or attend a dulcimer workshop where D tunings are the norm, but when practicing or playing for myself I prefer the feel I get with the lower tuning.  

The advantage of the lower tuning is a more flexible string that is less resistant to fretting, hammering, or plucking with the left hand and more easily strummed or fingerpicked with the right hand.  In short, I am more relaxed when the strings play more easily.

Obviously, there is a limit to how much the strings can be lowered, but I have found that the tuning of most dulcimers can be lowered a full step without creating any problems with loose or rattling strings.

Does anyone else experiment with tunings higher or lower than standard D tunings by adjusting string tension to achieve a more comfortable and relaxed feeling in the fingers making contact with the strings?