Scientifically verify your tambura tuning

[uday_shankar]

Without the use of any electronic gadgets I may add , doing it the old fashioned way. Could be of interest to tambura (sound) lovers:

https://m.facebook.com/story.php?story_ ... tid=ZbWKwL

Also at
https://youtu.be/Ttu7ldGX6VA

[thenpaanan]

Without the use of any electronic gadgets I may add , doing it the old fashioned way. Could be of interest to tambura (sound) lovers:

https://m.facebook.com/story.php?story_ ... tid=ZbWKwL

Also at
https://youtu.be/Ttu7ldGX6VA

Nice post. I was thinking that one thing you could add in the video is a demo of the actual process of tuning using harmonics. For example the demo could show that as you get closer to the perfect pitch the beats get slower and slower until they seem to disappear altogether. And you can stop when you cannot discern any beating at all.

Another idea which I use is to repeat this process an one octave higher. Because doubling the frequencies of the strings doubles the beat frequency as well, it is easier to hear the beats and get more accurate tuning. So strings that seemed in unison the first time suddenly show beating. The downside is that the strings don't produce as much volume at higher octaves and you have to listen very carefully.

All in all, a very enjoyable topic, and a bit of a nostalgic throwback to acoustics in this era of electronics. Thanks for posting.

-T

[uday_shankar]

Another idea which I use is to repeat this process an one octave higher. Because doubling the frequencies of the strings doubles the beat frequency as well, it is easier to hear the beats and get more accurate tuning. So strings that seemed in unison the first time suddenly show beating.

Excellent suggestion, thanks Will make another video.

I was thinking of such things after making this unplanned, adhoc video ! I didn't even realize that I was looking fairly ghastly too, one sweaty evening in Madras!

In fact the beating at the higher harmonic is a solid case against any false sense of security that one is "only a few cents off" at a certain low pitch. The cents, as you know are calculated as log2(f2/f1) where log2 is logarithm to the base 2 and f1 and f2 are the frequencies of two strings. The quantity f2/f1 remains unchanged no matter the harmonic, so the cents difference remains the same. Meanwhile the actual beat frequency in Hz goes n*(f2-f1), where n is the harmonic number. Any beat frequency beyond 0.5 Hz is unpleasant. So very quickly we come to a harmonic that accentuates the beats, perhaps as early as the second harmonic. In the above video, that's one of the reasons I suggest that for the mandhra or kharaj string, one tries to bring its second harmonic in exact unison with the two saranis which are in exact unison, So you have three exact unisons - the two saranis and the second harmonic of the mandhra sa. As you say, it would have been more illustrative if the process of beat reduction is better demonstrated.

All in all it is a pleasant experience of nada when the strings decay evenly without beating. One danger of not ever being able to achieve it is that the inherent inharmonicity of strings can ensure that there will ALWAYS be beating. This is complex, but qualitatively short scale length, somewhat slack, thick strings lead to inharmonicities. So we are better off if strings have long scale length, are thin and somewhat taut. So a really long tambura with thin, taut strings will exhibit less inharmonicity.

[thenpaanan]

All in all it is a pleasant experience of nada when the strings decay evenly without beating. One danger of not ever being able to achieve it is that the inherent inharmonicity of strings can ensure that there will ALWAYS be beating. This is complex, but qualitatively short scale length, somewhat slack, thick strings lead to inharmonicities. So we are better off if strings have long scale length, are thin and somewhat taut. So a really long tambura with thin, taut strings will exhibit less inharmonicity.

Indeed. I remember when I first got my tambura and learned to tune it, I would spend hours simply tuning it and forget to do my actual practice. It was so mesmerizing to achieve unison that I would sometimes deliberately mistune the strings and do it all over again.

As for the inherent inharmonicity, this turns out to be a real problem for male sruthi tamburas because the strings are not all of the same material. My own Ramjee foldable tambura has the center two strings made of string and the other two of wound copper (or whatever that construction is called). As a result, their audio spectrum as well as volumes are very different. The manthra sadja string is so loud that it drowns out the other strings, making it hard to even judge if it is in tune. Techniques such as the one you demonstrated in the video help overcome this problem. I have not seen a full size male sruthi tambura that has all steel strings. It must have been true with older generation makes but I have not yet come across one.

-T

[thenpaanan]

All in all it is a pleasant experience of nada when the strings decay evenly without beating. One danger of not ever being able to achieve it is that the inherent inharmonicity of strings can ensure that there will ALWAYS be beating. This is complex, but qualitatively short scale length, somewhat slack, thick strings lead to inharmonicities. So we are better off if strings have long scale length, are thin and somewhat taut. So a really long tambura with thin, taut strings will exhibit less inharmonicity.

Not to speak of the practical difficulty of doing this on stage. Once had a tambura lose tuning when someone helped carry the instrument to stage (people don't always know how to hold a tambura, this gentleman made a giant fist of the tambura stem, strings and all ) so there I am sitting on the stage doing this weird tuning thing. People looking at you strangely is one thing (which I couldn't care less about) but doing this kind of fine tuning on an extremely noisy stage with people talking and other instruments sounding off is nearly impossible.

-T

[uday_shankar]

but doing this kind of fine tuning on an extremely noisy stage with people talking and other instruments sounding off is nearly impossible.

-T

Ain't that the Truth now .