Problems With Duplex Scaling Of Pearl River Grands?

[Richard Brekne]

Hi Terry, and thanks for the welcome back !  And yes... it is a nice 
life here in Europe once one is firmly established.  At least here in 
the northern part. How long life will continue to smile so generously on 
us northerners is an open question.... but as long as it does it is most 
certainly a very comfortable place to make ones way in life.


Comments re-interspersed amounst the previously interspersed 
comments.....er.. or something like that :)

    Comments interspersed:

    ----- Original Message -----
     > I'm not sure I agree Terry. In your last post to Andrew you state
     >
     >    "When we "detune" a front or backscale, don't we specifically
    try to
     >    avoid a fractional length of that note's speaking length to quiet
     >    the front and/or backscales?"
     >
     > which implies it DOES make a "whit" if the back duplex is tuned to a
     > specific relationship to the speaking length.
     
    Correct. Did I not say that? Perhaps I wasn't clear. Indeed, that is
    my understanding of "tuned" backscale designs - make the backscale
    some fractional length of that note's speaking length.

I thought you had just voiced agreement with Ron's post which seemed to 
discount whether it mattered or not that the back duplex was tuned to 
any particular relationship to the speaking length.  Seemed to me that 
if one agrees with that statement... then one goes contrary to the 
concern you express above as to why we detune. 

Actually, these discussions always seem to carry a good deal of self 
contradictory statements. The stability bit for example.  If one claims 
that the likelihood of the backlength to remain at a tuned pitch is very 
low... then one is basically saying the pitch of the back length will 
vary quite a bit... which would be the case if it was aligned as to be 
detuned as well...which would mean that regardless of what the heck you 
did with it, it would find itself sometimes in tune and sometimes not in 
tune with the speaking length.  And if thats the case well its all a 
moot discussion to begin with.  If one wants to take the position that 
the detuned state is the only good one... then one has to acknowledge 
that the pitch of these back lengths will remain stable enough to remain 
detuned.... which pulls the rug from underneath one of the main 
arguments against the back duplex to begin with... namely its 
stability.  This kind of thing, as you know by now.. :):)... drives me 
crazy !


    The only thing I was trying to point out was that if C6 (for
    example) has a "tuned" backscale, some partial of C6 should excite
    the C6 backscale. The original post suggested that C6 speaking
    length would not excite a fractional-length C6 backscale, but rather
    some other note elsewhere on the piano would - and yes, other notes
    will also excite C6, but my point was that C6 will also excite it's
    own "tuned" backscale.

I would suggest that the back length gets pretty much just as excited 
one way or the other..... or if it actually DOES get more excited by 
being "in tune" with the speaking length... then the whole idea that 
this state doesnt create <<more>> sound becomes a self defined erroneous 
type claim so to speak.  Ok... one can choose to define this extra sound 
contribution as pure noise.... or one can choose to enjoy that sound and 
call it part of the musicality of the instrument... but thats another 
discussion entirely... and an entirely subjective one at that.  My own 
view is that in keeping with what we think we know about the way coupled 
strings work together... very closely tuned frequencies tend to extend 
sustain somewhat.  Exactly tuned theoretically tend to cancel each other 
out...effectively reducing sustain... and frequencies that are close 
enough to interfere with each other but not close enough to do either of 
the aforementioned will create a kind of false-false beat effect.  I 
find this last quite frequently when tuning the top octave / octave and 
a half.  Always a few notes where some backlength down the scale is 
causing some 5-6-7 or so bps interference that muddies up the sound.  
Normally that segment can get tuned to fit appropriately... at worst I 
can felt off that single back length unision.


     > Once accepted that
     > certain relationships to the speaking result cause clear and
    predictable
     > acoustic results... you are immediately into a judgement call as to
     > whether the results are desirable or not.

    Agree. Correct. But I was not making any comment on whether the
    "tuned" duplex scale is desirable or not.

Ah.. there you and I are on the same page. 


     > Strikes me that manufacturers are all out to make things as cost
     > effective as possible... if the whole basic back duplex idea was
    totally
     > ridiculous to begin with... no amount of marketing can account
    for the
     > fact that so many manufacturers are wasting so much time, money and
     > resources putting them in.

    I'd disagree with that. If it sells, why not waste time, money and
    resources. Can you say "CAPITALISM!"?

I'd say that marketing tho clever is not stupid... if they can market 
some expensive way of doing something that is useless... even less then 
desirable... then surely they can market some less expensive way of 
doing that same thing that creates at least as desirable an acoustic 
result.  THAT, is capitalism !


     > Another thing... when I stop to think about
     > it.... I dont see any data supporting the idea that the basic
    Steinway
     > back scale idea doesnt work.  I just hear a lot of claims.  

    I wasn't commenting on that. However, since you bring it up, I claim
    to have no claims - only an opinion - I don't care much for them,
    IMHO they are rather noisy.

I have to say that the only back scale configuration I find generally to 
be lousy sounding (purely subjective on my part mind you) is the 
Grotrian Steinweg setup. They use just about every possible non-speaking 
length to contribute sound and it all comes out as a kind of sizzling 
wash of echoish cymbal decay if you ask me... a quietish but 
particularly annoying whooshyness to the whole sound.  That said I know 
lots of folks who just love them for exactly that character.  The only 
other back length effect I find annoying is when some segment is some 
few bps away from some speaking length frequency and gets too much into 
the picture when that speaking length is sounded for it to come out 
clean.  Otherwise... I dont find them annoying at all one way or the other.


     > Today I used
     > a bit  of ekstra time tuning the top 6 notes on a C I service. I
    tuned
     > the back lengths to exactly the same frequency as the  speaking
     > lengths....  I got a very clear and definite improvement in
    sound. Much
     > cleaner, increased sustain and volume.  At least thats what my
    ears told
     > me, and it seemed pretty darned obvious.

    Okay. I've never tried to tune them to anything. Maybe I will some day.

Try it... what can I say ?

Cheers
RicB

     
     > Cheers
     > RicB

    PS:

    Welcome back!

    Last week I tuned a piano for a woman who just moved back to the USA
    from 8 years in Germany. We talked about the laid-back lifestyle and
    attitude that seems to prevail in Europe (and Scandinavia, no doubt)
    compared to here in the USA. I really haven't had a vacation in 19
    years, unless you call four days at a PTG convention a vaction. I
    envy that lifstyle. It sounds very good.

     >