[baddox]

It's not intuitive to me how big of a difference 4.5 Hz is, but you really need to use a logarithmic scale (because, for instance, shifting everything up an octave will yield different errors in Hz). In cents, that's about a 16 cent difference, while an equal tempered semitone is 100 cents. Is 16 cents easily noticeable? I don't have a nice tuner handy, so I can't say.

Still, your claim doesn't seem right to me. A perfect tuned guitar with perfect intonation in equal temperament will play the same frequencies as a perfectly tuned piano. Yet, when I play G and E chords on a piano, I don't notice the same tuning issues as I often do on guitar. That's why I assumed the bigger issue on guitars is intonation.

[BrianHV]

Yes, I should have gone logarithmic. But I spent enough time playing with that. Had to get back to work. ;) Thanks for figuring out that it's 16 cents. And yes, 16 cents is very noticeable. I might even say dramatic.

The thing is, tunesmith wasn't talking about a perfectly tuned equal temperament guitar. We're talking about tuning a guitar by ear so that one chord is sounds perfectly in tune (i.e., is in just temperament), then trying to play a different chord. It's going to sound off for the same reasons a just-tempered keyboard would. And as someone who constantly has to resist the urge to tune his B string too high in G major, I can tell you this isn't just a theoretical assertion.

That said, I have played on guitars (especially electric ones) that seem to resist sounding in tune even when the open strings are tuned "perfectly." Maybe that's a fret spacing defect in action. But it doesn't make the tuning-by-ear error negligible.

[baddox]

> The thing is, tunesmith wasn't talking about a perfectly tuned equal temperament guitar. We're talking about tuning a guitar by ear so that one chord is sounds perfectly in tune (i.e., is in just temperament), then trying to play a different chord.

When I reread your comment, I realized that this is what you were talking about. In that case, you're absolutely right. Although it is a pretty bad idea to tune a guitar by ear by playing a single chord. Not only will other chords sound out of tune, but even slightly different voicings of the same chord. A guitar that's designed for equal temperament really needs to be tuned as such. Correct me if I'm wrong, but I think the standard ear tuning technique (where you match the 5th or 4th fret of one string with the open string under it) will give much better equal temperament results.

[ArkyBeagle]

16 cents is a lot. It's 1/6th of a semitone.