bobg wrote:pablus wrote:I played 640mm for more than 2 years. Once my fingers got used to it, every time I picked out
my flamenco guitar, 650mm, I felt like it was a very big instrument. I sold my 640mm eventually since not only it
did not improve my playing but I got a bit of unwanted tension in my left hand. The reason for that was that
my 640mm got string spacing at nut a bit too narrow for me (I like 43.5mm). My hand span is around 8".
My lesson is that the most important parameters in a guitar are string spacing (at nut and saddle)
and neck thicnkess (I like very thin). Try to optimize these things first.
Finally, if my hand span was 7" I would definitely go with 640mm or even 630mm.
It's my understanding that a 'standard' 650mm guitar has a 52mm nut width. Do you have a 650mm with 43.5 width? If so, is this a custom guitar or a specific production guitar? I would be very interested in anything that could make life easier for my left hand.
With 8-1/4" hand span, my 630mm is difficult to bar with '1' and simultaneously span past three of the lower frets with the '4' finger. I can do it but I have to hit it just right. At best, it's not a pleasant experience. Nevertheless I can still make this span on a 650 at which point it is down right painful. I think it partly has to do with the strength in the '4' finger. Being an old geezer, strength takes a long time for me to develop. Fortunately, there isn't a lot of call for this particular acrobatic. Unfortunately my favourite piece requires it.
I also have a 3/4 student guitar which is quite a bit easier to play than my full width 630mm but there's not enough clearance between the strings and the sound is not very good (cheap guitar). It sounds like a cross between a guitar and a ukulele.
I find that playing different sized guitars is easy if you have the piece memorized and can look at the fretboard. It might be a little trickier with sight reading.
All my guitars have been built to my specifications by luthiers. I do have a 650mm wit 43.5mm string spacing at nut.
I find it easier to play than 42mm as my hand is more relaxed with the wider fingerboard/string spacing.
There are many other playability aspects but at least two parameters can be checked. First is to shorten the scale length
by using a capo and see if the guitar plays better. 650mm with a capo would give 613.5mm. String spacing at nut can be optimized by installing a nut with some wider/narrower spacing.
Again this can be done without a problem on an existing guitar (as long as the fingerboard is wide enough).
I also like thin necks and tall frets, and feel that they improve my playing.
Its difficult for me to give a specific advise for you since the age and the inevitable loss of dexterity comes into play. For me 630mm is small already.
Other things that may helpe are: trying lower tension strings. Checking if the guitar has a good setup, no excess relief, neck is staight etc.