leftyguitarman wrote:Thanks for that post, Freeman. I didn't know they were intended for spiders, but that makes sense. I pretty much keep it tuned to open C# and the tension really isn't that bad. But I'll be sure not to tune it up very high. I actually have it tuned, low to high, CGCGCC right now. I've been using it to learn a Gov't Mule song called "Like Flies." It's an, uh, interesting tuning.
I have one guitar that I keep in open C (CGCGCE, low to high) for a couple of Fahey and Kottke songs (I've actually tried it with a 12 string but its a huge hassle). Since the bottome three are tuned WAY down and the 2nd is tuned up from normal I have found that a set of lights on top and mediums on the bottom work fine on the old Yamie - however once strung that way it becomes pretty much a dedicated open C git.
(Btw - lefty, where in Washington do you live? I happen to be in Wenatchee where it is currently snowing sideways)
ricbleu wrote:Freeman, if you use 13s tuned to open D, would 12s tuned to open E do any harm to my biscuit cone? Originally I had the 12s at open D but found the two steel strings too slack, so I tuned her up to E but I don't want to stress the cone. Other alternatives are 11s at open E or, like yours, 13s at open D. So what do you think of my current setup of 12s tuned to open E? Many thanks.

Peace.
I am not an expert on string guages and tensions and all that stuff, but I have fooled around with it a bit. A couple of rules of thumb - if you go up in gauge a standard set and down one semi tone you will maintain almost the same tension. IE, in standard tuning 12's at concert, 13's at D# and 14's at D all have very close to the same tension. I use this when I think about down tuning - try to maintain the tension that the guitar was designed for and everything will work the same. OK, so in your case you are going up TWO semi tones but only decreasing the guage by one - therefore your overall tension will be going up.
A quick way to check this is here (I keep this puppy book marked)
http://theunofficialmartinguitarforum.y ... ng-TensionThe way I use this is whatever the manufacture recommends (lets say its an OM that ships with lights - the guitar was designed for roughly 165 pounds). Find the tuning I want and make sure that the I don't go much above or below that number - the guitar will sound good and won't break. For funky tunings (we wouldn't do that, eh) I keep this bookmarked also
http://www.daddario.com/DAstringtensionguide.PageGo to the "down load all.." tab - now you can maintain the same tension on each string - if you were going to do a custom set for open C this is how I would figure it out. We had an interesting discussion the other day with someone who wanted to tune his Les Paul as a baritone - I sort of showed him that it wasn't going to work very well.
Last comment is about resonators. Again, I'm not an expert but I have done some setup and built one. I'm also an engineer and once did the calculations on the down force into the cone at various string break angle with different gauges. I don't have the number here but it was something like 10-15 or so pounds with mediums at open G - think about that, a 15 pound weight supported only by that thin spun aluminum cone. I once asked Scott Anslie how he gets by tuning his single cone to open A - he said "lights and low break angle"