[CAUT] Duplex

[RicB]

Hello Ron.

I must by and large agree with much of your post. Quite a bit of whats 
said here is exactly what I've been saying all along. Energy passing 
across the capo and onto the front length is largely the same regardless 
what termination system is used.  Thats is, as I understand it a given 
in the Steinway solution.  They simply believe its something that can be 
utilized to color the overall sound... and I'd say they were right.  I 
don't consider Steinway duplex in any way a poor design. It is what it 
is, and it does what its meant to do.  And well kept it performs in a 
manner that many find attractive.

There are a few points I would like to take issue on.  There is good 
reason to believe IMHO that the profile of the capo is quite a bit more 
important then you make it out to be below.  Inharmonicity is measurably 
lowered... and that makes it significant from the standpoint of 
effective dynamics.  Since the capo profile makes the string less stiff, 
the hammer is able to deflect the string that much more, in essence 
increasing the dynamic range of the string.  The other point I'd argue 
is what are the determinants for string noise... i.e. leakage to the 
capo (as opposed to across the capo). While I agree entirely that the 
longer the front duplex and less steep the counterbearing angle the 
higher the propensity for string noise, this can be to some degree 
compensated for by the thin V profile.  The trade-offs are well 
discussed already so unless someone insists on going back through that 
I'll leave it at that.

One other point.  String noise is a potential problem no matter what 
system is employed.  I have yet to run into a single instrument that was 
problem free in this regard. Yamahas of earlier date were simply plagued 
IMHO by string buzzing at the capo.  Especially so at the break between 
capo and agraffe sections. Todays Yamahas are not all that much better 
outside of the S series. Agraffes themselves buzz routinely wherever 
they are employed.  There is no magic bullet here and no system that is 
so significantly more problem free then another that it justifies 
closing out the sound pictures created by any other given system 
routinely employed today. Not IMO anyways.

That said... everyone has to choose their own road.  And I for one 
totally respect the decisions each makes.  I've re-profiled over a 
hundred instruments at this point... and many of these are still under 
my care or I get to see them from time to time.  Like Ed... I just do 
not see the big re-occurring problem.  Thats my personal experience.  
And in like fashion to yourself.... I see no reason either why anyone 
should be prevented by this from believing anything else.

Cheers
RicB


    I agree. Whether the capo shape is sharp or rounded is of
    little practical consequence to either inharmonicity, or
    energy transmission across the capo. While the sharper profile
    may be less prone to front duplex noise in poorly designed
    systems, it isn't all that important in systems with short
    front duplexes. Energy still passes across the capo with the
    rocking motion either way. The short front duplex just doesn't
    let it make unwanted noises in the process. Go to any piano
    with a capo and front duplex. Long, short, tuned, or not, it
    doesn't matter. Hold up the damper for a given unison, pluck
    the duplex segment and listen. What do you hear? With a very
    long tuned duplex, you might hear some of the tone the duplex
    is producing. For the most part, you'll hear the fundamental
    of the speaking length of that unison because the rocking of
    the string on the capo has started the speaking length
    vibrating. Try it on a vertical piano with the shortest
    segment you can find between the V mound and the pressure bar,
    and you'll hear the fundamental of the speaking length.

    I'm not sure it's even possible to entirely prevent energy
    transmission across a capo without a clamp, however large the
    radius may be in an actual functional instrument, but the
    primary determinant of duplex noises (attributed to capo shape
    or not) is the combination of long duplex and low bearing
    angle. As long as that combination exists, capo and duplex
    noises will always be a potential problem no matter what you
    do to the capo.

    But that's just my opinion from personal experience of
    actually trying it, and shouldn't interfere with anyone else's
    belief to the contrary.

    Ron N