Sam Spoons wrote: ↑Sat Jun 18, 2022 10:39 pm The G, D and A are significantly thinner than a 'normal' 13's set and different materials densities would make up the rest of the difference…
That should have read “pinless bridge”.
Mine are custom sets: 13, 17, 25, 35, 45, 57; round core, phosphor bronze. They’re not significantly different dimensions to the conventional set.
Last night I compared a fresh set of Newtone and D’addario non-coated Phosphor Bronze 13s, on two Lowden cedar top O models (a 1988 S22 and 2004 23), both of which previously had the NT set. As well as I could, on each I compared the old NT plain strings with fresh D’addario’s; then those with fresh NTs on the 22 model, using the same number of wraps around the tuner post on each. Even though well stretched, I can’t exclude the likelihood that being new has a fair impact on their feel. I also can’t exclude the D’addario’s not suiting those guitars particularly; they and Elixir always felt too stiff.
On the 23, for approx. 10 mins I played exercises, then melodies along the existing NT plain strings, then full arrangements across all to assess their apparent tension. Once changed to Ds and thoroughly stretched for 5 mins, I repeated the same exercises, melodies and arrangements; likewise on the S22. With a short break, I repeated again regularly switching between the two models. On the S22 I put a fresh set of NT with the same MO, played them in for 20-30 mins to compensate and after a short break compared each guitar.
Allowing for manufacturing tolerances of both the strings and guitars, there does indeed appear to be a significant difference in feel between the NT and D. The NTs when brought to pitch, seem to produce an extra wrap around the tuner post. On the NTs 13, I can bend up by 5 semi-tones with ease; whereas the Ds 13 just shy of 2 tones with some difficulty. Tentatively I’m satisfied the NT strings of similar gauge are lower tension.
Sam Spoons wrote: ↑Sat Jun 18, 2022 10:39 pm …I can't help thinking just using a lighter gauge would get you the same benefit..
Not really, that would only solve the tension issue. The additional mass of larger gauges very much affects pitch stability, feel and tone, especially with alternative lower tunings.