[CAUT] Scientific Testing

[Ric Brekne]

Hi Jim.

First off let me say I aggree totally with you on the point about 
scientific testing. That is to say if the rules of scientific method are 
reasonably closely adhered to. We've all seen plenty of examples in past 
and present where psuedo science is used to attempt to "prove" some 
forgone conclusion.  Good science simply shows facts for what they 
are... when the facts are available. What conclusions we can draw from 
them are a bit more iffy ofte as not, but there is much that good 
science can confirm or rebuke to be sure.  That said... I am not aware 
of any real studies on this particular back scale coupling topic that 
can say one way or the other. I do see some sensible argumentation on 
the one hand by folks like yourself. And on the other hand I see a lot 
of folks out there claiming their aural observations lead them to the 
opposite conclusion.  Having that healthy degree of the skeptic as I 
do... I am willing to admit that I personally dont have enough data to 
do much more then be open to both sides until the question is answered 
one way or the other.

As to what I did...  It was simple.  I just plucked the backlength of a 
string that I had undamped (using the sustanato pedal).  I found bleed 
through in every case.  When I attempted to pluck the back length of one 
string and hold its neighbor unison undamped in similiar fashion... I 
got no bleed through.

Then there is the other question I posed... about 
complimentary/confliction vibrational frequencies working on the bridge 
at the same time.  It would seem to me likely that if a strings 
backlength had a close enough frequency to a given partial of its 
speaking length, then one should expect a more efficient transfer of the 
speaking lengths energy to the bridge.  Isnt this supposed to decrease 
(however slightly) sustain and increase power ?

Cheers
RicB

Jim Ellis writes:

Ric Brekne and Mike Jorgensen struck a nerve in me with their latest posts
on this subject.  Ric, when you tested to see if plucking the string tails
would excite the speaking lengths of close neighboring speaking lengths,
did you test to see if the those tails were tuned dead on with the partial
frequencies of the speaking lengths of the strings they did NOT excite?  If
you are going to do that test, you need to be sure exactly which is tuned
to what, and how far away it is - how much and how little coupling occurs.
If no frequency component of the speaking length is resonant with the tail,
you are right.  It won't couple.  That also goes for the corresponding tail
and speaking length - that is, unless you have a faulty bridge termination.
 If the bridge termination is NOT solid, then yes, it will.  If the bridge
termination IS solid, then the coupling will occur in groups - not
individual speaking length to corresponding tail - but ONLY if the tails
are resonant with the speaking lengths.

Also Ric, you were right when your said, ..."deserves a bit of hard
science...and probably won't get much".  That's often the way is is, and
when people like Mike Jorgensen say things like, "scientific testing is
inadequate to prove false a claim made by many experienced persons", it
supports that scenario.  I strongly disagree with you, Mike, provided the
scientific testing is properly done.  All too many times it is not, and
therefore passes off as "scientific" when it is not.