[CAUT] Duplex angle

[RicB]

Hi Alan.

I dont really see that an experiment is necessary per se. Anything that 
comes in contact with the string only part of the time will cause a 
buzz... and suck up whatever energy goes into making the buzz.  
Conceptually... its the same thing as putting a penny on a unison and 
putting the string into vibration. Its just that instead of a free 
floating penny... its the edge of the capo / part of a groove / or in 
general poor contact.  The same thing would happen at the bridge if we 
didnt use bridge pins to hold the strings clamped.. yes ?

But if you must have some kind of experiment to demonstrate leakage 
across the termination, simply build yourself a monochord with the 
ability to alter the length and angle of the front duplex length. Then 
pluck the front length with some standardized force and measure the 
output of the speaking length.  You will find the angle and length are 
not nearly so related to this output as you might think.  On the other 
hand... there is indeed a clear and significant relationship between 
these same angle and length quantities as it relates to loss TO the 
termination (as in buzzing). And another clear relationship between 
these two along with the profile and hardness of the capo as it relates 
to long term wear... which can lead to buzzing over time... or string 
breakage... or other issues.  There is a lot to balance and the fact 
that there has been tried so many configurations attests to that.

Think of it this way Alan.  You have two things here.  Buzzing at the 
capo itself and a vibrating front segment.  Are they the same thing ?  
Of course not. I think the idea that they can be thrown into the same 
box came about because a group of techs not liking the front duplex 
sound as a whole decided to just define all sound coming from this 
system as noise.   This is clearly a misnomer because the definition of 
noise is along the lines of "random frequencies" where as the front 
segment is far too clearly defined.  And no... it does not matter that 
the actual frequencies deviate from the intended ones to some degree... 
there is a clear pattern and element of design to the front segment 
lengths. That simply precludes the idea of randomness.

Just as a kicker... I was on an old B today.  Just for fun I used a 
small pick to pluck at several front lengths to see what kind of output 
I'd get for the speaking lengths. Two agraffe's and two capos. You 
couldnt hear a difference in output at all.  Perhaps one is 
measurable... but the difference wont be much.  Angles up on the 
agraffes were about 15 degrees and the capo a bit steeper. Front lengths 
were standard at the capo for S&S and about 10 mm for the agraffes.

Hope this helps.

Cheers
RicB



    OK. I hear you. So you must have devised some kind of experiment to
    prove
    this to yourself - that the buzzing that we hear is not excessive
    leakage
    across the capo, but is leakage to the capo instead. I'd like to be
    able to
    do that experiment myself. Can you describe your experiment so that
    I might
    be able to duplicate it?

    Alan