Re: OT: high-precision tuner app

[Andrew Bernard]

Hello Andrew,

Apart from doing engraving scores with lilypond, I am also a harpsichord maker 
(and tuner obviously) and a player. I have decades of experience doing 
professional tuning. Also having a background in maths and computing, I take an 
interest in temperaments, tuning theory, and tuning programs.

There are many tuner programs for Android available. But the ones that let you 
enter and tune custom temperaments only support 12 notes per octave. As far I 
am aware there are no programs that support more notes per octave. Also, in 
relation to accuracy, no phone tuner app is more accurate than 0.1 cent. in 
testing, even that is doubtful, to tell the truth, and you are lucky if a phone 
is accurate to one cent (depressingly). You cannot find a program that is 
accurate to 0.01 cents as you require. One reason for this is that phones do 
not have particularly accurate ADC/DAC chips. The other reason is that the ear 
simply cannot hear a hundredth of a cent difference, even when comparing two 
notes in a just intonation and listening for beats and so on. There are many 
papers in psychoacoustics that have established this.

It seems to me that what you actually want is a high precision frequency meter 
instead. There are tools like this for computers, but you are unlikely to find 
that sort of laboratory accuracy application for a mere phone.

If you have a Mac you could look at:

http://www.faberacoustical.com/apps/mac/electroacoustics_toolbox/

Or  could use this for accurate frequency measurement:

http://www.baudline.com/index.html

Other than that, better write your own app. I am sure there are a lot of just 
intonation folks who need such a tool.

Andrew