Okay, well I made a thread a while back about how I was going to get my guitar set up for C standard at my local shop. Well the guy there told me that on the frets 11-24, it probably would be about a quarter step out of tune because my guitar wasnt a baritone, is this a major issue? It's a washburn X40 Pro if you're wondering, and is this true?

My things:
Bowes SLx7
Washburn WG587
Washburn X40Pro
Washburn X50
Washburn HM24
Washburn WR150
Laguna LE200s
Arietta Acoustic
First Act
Valveking 112
VHT Deliverance

Well, that sounds like an intonation problem indeed.

The fact that your guitar isn't a baritone doesn't make it impossible to have the intonation set properly.

If you don't know how to do this:

1) tune a string using an electric tuner; make sure it's perfectly in tune

2) compare the 12th fret harmonic with the fretted 12th fret, again using a tuner

3) if the two notes are slightly apart, adjust the saddle a little, retune and check again

4) repeat this for all the strings

That should get it set up pretty nicely. Personally I have a Fender Strat tuned to B without any real intonation issues.
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