back check, a magical mystery tour.

[Richard Brekne]

Isaac OLEG wrote:

>Hi , everyone,
>
>Even if the theory is saying that the action will flex a lot, it is
>under very heavy play.
>The amelioration with the optimum backchecks height is (to me felt as
>a difference in synchronization, if one drive the backchecks even
>lower, the tone get more power
>
This one I havent heard anyone claim til now. And to my ears the tone 
does not just continue to get stronger the lower the backcheck is set.  
I have tried this but was not able to find any further increase in tone 
strength or sustain, and personally felt like there was a tendency to 
the opposite. But this was a while back, just after Andrè was here and I 
have not repeated the exercise since, nor have I gotten around to asking 
him about it.  The other day I asked something along those lines and I 
thought the reply was along the lines the 2 mm was an optimum,  more was 
not much better then less.  So I can see I am going to have to try this 
out again.  Even so.. I dont see that this rules out the possibility of 
unaccounted for drag between the check and the tail per se. In any case 
any such drag should be something one could observe beyond what bench 
testing for backcheck adjustment tells us. In otherwords... that bit is 
easy enough to confirm or dismiss by empirical means.

As for the synchonicity bit. The more I think about this the more 
difficult it seems.  I mean there is really nothing changing in terms of 
timing if the check is set to 15 mm from the string regardless of the 
height of the check on the key stick.  This on top of the fact that 
given the extremely short time spans we are talking about in the first 
place... milliseconds even in the softest of actual playing modes makes 
me skeptical that anyone would be capable of feeling a difference in 
synchronization if the only thing changed was a 2 mm back check height 
(keeping checking distance the same).  Could be interesting to do a 
blind test on this... bench action no strings. 

I certainly agree a lower check height will tend to mean a stiffer check 
due to the shorter length of check wire exposed, but this is something 
else entirely.

I liked Phils observations, and tho Andrè will no doubt chirp in for 
himself, I dont think he simply means the harder the better as obviously 
a punching can get too hard to be usable from several standpoints.  I 
think, as I understand him, that the harder punching provides both the 
psychological effect Isaac described, and also provides a firmer 
endpoint that will absorb less shock, and hence steel less energy from 
the key. I remember one description he used...he said the harder 
punching provides a stronger catapult to launch the whippen and hammer 
with. Seems to me he was talking about how much flex in the key is 
absorbed by the punching.

I want to think more on what both Phil and Stéphane had to say but....

Phil Ford:

    "I put that in quotes because it's not clear to me whether the
    action noise is in fact 'masking' the sound output from the strings
    or if in fact is an integral, and perhaps desirable, part of what we
    recognize as piano sound. Also, with regard to modifying the
    waveform output of the soundboard, it's also unclear to me whether
    this action noise is being heard directly (just something extra put
    on top of the sound coming from the soundboard, so to speak) or if
    this noise is traveling through the keybed, case, etc. to the
    soundboard and modifying the sound output from the soundboard. Or,
    perhaps more likely, a combination of both."

This bit was particularly interesting.  Isaac notes an experiment where 
piano sound was picked apart into several component parts. In Benades 
book this same is done for a series of various instruments, everything 
from  violins, to bassoons, to just about any instrument you can think 
of.  It was found that without the attack moment and decay  it was 
extremely difficult to recognize one instrument from the other.   So at 
least in any usable sense in the word I think that the piano sound we 
recognize has to be inclusive of all the contributing sounds. I doubt in 
most instances that either pianists or listeners are aware directly of 
any particular component part. Rather, if they were, this would probably 
be associated with some kind of an undesirable sound...something that 
didnt belong if you get my meaning...

Cheers
RicB


Cheers
RicB