New Release of GuitarTune v0.20 (based on Alsa)

c_c cchandel at
Thu Feb 5 14:11:57 CET 2009


Ed Kapitein wrote:
> ... so when playing a G the tuner hears a A.
 Well, I only own two accoustic guitars - and it seems to be quite accurate
for me. But then fundamental freq detection is not a guarantee with the
signal processing I'm doing. There are many things that can throw the tuner
off - like background noise for eg or the particular characteristics of the

So, here are some questions that would help me understand the approach to
take to make the program more accurate.

Are you using an accoustic guitar? 
Is the tuner consistently hearing a higher note?
Could you verify by using some other tuner what the error is?
Could you try after keeping the freerunner really close to the guitar?

Ed Kapitein wrote:
>  is it possible to select manually which string you try to tune? it could
> filter the input signal at that frequency and perhaps make recognizing the
> correct tone easier.
Well, the current method I'm using (FFT followed by a harmonic spectrum
product) wont be affected by knowing which string you're tuning. 
Then again, I could use another method of determining the fundamental freq
(goertzel algorithm) perhaps, which would need to know the target freq.
Though that will be totally different program.

So, right now, I would prefer trying to get some feedback and improving the
code to see how it can be made more accurate. And your feedback would help
the most since you're the first one to tell me its off :-)

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