[Harp-L] Subject: Re: 2010 Comb Test - the Facts

[EGS1217@xxxxxxx]

Has everyone forgotten so quickly? 
 
Brendan first posted a po'd post on both the MBH forum AND harp-l about the 
 2010 Comb Test and then followed up with this a week later. I remembered 
it  well so dug it up. I've inserted Chris Michalek's post from MBH where  
applicable.
 
Elizabeth
 
PS: As is obvious from the test and the following, TWO other players  
(participants in the test) scored the results the same way Chris did, but  he was 
the only one who outed his own comments. 
 
 




"SPAH Comb Test: Retraction and Apology 
from Brendan Power.
--------------------------------------  

Thanks to Vern for his comprehensive round up of our recent Comb Test at  
SPAH. 

It was interesting and enjoyable working together to make it  happen. As he 
says, it was an exercise in (trans-Atlantic) co-operation and  compromise. 
In the months leading up to the test there were lots of detailed, at  times 
impassioned emails flying back and forth, arguing for this procedure or  
that. I wanted lots of combs, he only wanted two etc etc... (The compromise  
there was that we had ten tests per player but only seven comb types, so we 
each  got what we wanted: the variety I desired and the duplication of tests 
Vern  insisted on). Similarly we eventually reached agreement on other 
initially  contentious issues.


We chose Marine Band reedplates and covers for every test, with  just the 
combs changing. In addition to the stock MB pear and bamboo combs and a  
suitably sized ABS plastic comb, respected maker Chris Reynolds supplied us with 
 the others to the same specs, ones commonly used in custom harps: brass,  
aluminium, corian, dymondwood.



Vern made a quick-change mechanism, which allowed for the combs to be  
switched quickly, and had a large weight attached to mask the differing comb  
weights (he has described the other ways in which comb differences were masked 
 in his report). On the day, Vern's task was to do the comb switches, and 
mine to  do the recordings.


We recruited six excellent players to test the harp/comb  assemblies: Dave 
Barrett, Chris Michalek, Alex Paclin, Cara Cooke, Brandon  Bailey and Jimi 
Lee. We assured them that their test scores would remain  confidential, and 
this has been honoured. We also had the help of Winslow Yerxa  and Michelle 
LeFree, who were invaluable on the day in making the test go  smoothly by 
moving equipment around and making everyone comfortable.


The test went ahead; to our pleased surprise we got through it all  in the 
two hours allotted. Afterwards both Vern and I got busy with SPAH  
activities, and it was only mid last week that I turned to the task of getting  the 
results and music clips online. That led to an emotional process in which  
I've come full circle on my assessment of the test.


When I saw the score sheets, I was really surprised and very  disappointed 
to see that three testers had given uniform scores for all combs -  two of 
them from beginning to end and a third shortly after the start. After all  
our hard work preparing the test, seeing a "3" in every box for every category 
 for every comb felt like a slap in the face, especially as the scores 
stayed the  same from start to finish. On the face of it, that looked like a 
strategy that  had been decided before the first test play. Unfortunately I 
reacted  impulsively, posting my angry feelings in my initial online Test 
Report.


However, a week of reflection and private discussion has totally  changed 
my opinion. I now think that the uniform scores were the most  significant 
and useful data to come out of this test.


The main reason received for giving the uniform scores is that the  test 
harp assembly was insufficiently airtight to give a clear distinction  between 
tests. A reason given by one tester who marked uniform scores is that  ââ
The only perceived difference seemed to be in airtightness and responsivness  
of the reeds as a result of differences in screw tolerances and comb 
flatness  between each comb switchâ the tests in the end were very inconclusive 
due to  large variances other than the comb materialsâ. 


Another has written that "I didn't hear any difference between the  
materials. What I did notice is the inconsistency between the poorly made combs.  
Between them, it took more or less pressure to sound the notes. I felt 
obvious  airleaks and could tell Vern was inconsistent in the way he screwed the 
plates  to the comb... I thought the test was very poorly executed and with 
subpar test  objects."**
 

EGS: [**The following was Chris Michalek's post on MBH showing that  the 
above comment was obviously his):
 

('Very disappointing to read that some of the players deliberately  
sabotaged this procedure."'

"Nobody I know did that.

I didn't hear any difference between  the materials. What I did notice is 
the inconsistency between the poorly made  combs. Between them, it took more 
or less pressure to sound the notes. I felt  obvious airleaks and could tell 
Vern was inconsistent in the way he screwed the  plates to the comb.


I would like to see results from combs that are precisely flat and  with 
plates that are properly set up. None of these combs were flat and the  plates 
were not well set up if at all.


We were told to compare them to our own harps and if I honestly did  that, 
I would have scored everything a zero.


This is in no way a reflection on Brendan or anybody else involved  but I 
thought the test was very poorly executed and with subpar test  objects.


I do have one issue though, to say that a tester, me in particular,  did 
not honestly take the test is rubbish. I work with harmonicas and combs to a  
level that most never will. I didn't sit there for two hours just to ****  
around."

----------
"All is bliss")]
**********************
 

EGS: - Back to Brendan's post(cont'd):


"That's a serious point, and deserves answering. As most of the  testers 
are used to playing high-level custom harps, possibly they were  comparing the 
test harp to the ones they normally play? However, it wasn't our  goal to 
replicate a custom harp, just to get average out-of-the-box playability  
similar to a traditional 1896 Marine Band, while still allowing for quick  
changes. I tried the test harp for the first time the day before the test, and  
thought Vern had managed to achieve acceptable playability for test purposes  
with his quick-change assembly mechanism. 


It sounded fine to me on test day when these six fine players blew  it, and 
their pieces sound good on the recorded clips. They are all great  players, 
and could make any harp sound good! However, on close listening you can  
hear this was not a high-level harp, and the leakage referred to can be 
detected  in some places through the evidence of extra unintended notes sounding  
occasionally.


Obviously some of the testers felt that this lack of perfect  airtightness 
was great enough to mask any comb effects there might (or might  not) have 
been. Essentially they thought the test harp was inadequate for the  task, as 
they have stated. Hence their uniform scores.


In our defence, we gave everyone the harp assembly to try in the  half hour 
before the test. It might have been preferable for those who felt the  
assembly was inadequate to have simply withdrawn from the test at that stage,  
rather than sat through two hours of their and everyone else's time giving 
the  same score for every test. We would have recorded their opinion, but we 
could  have given their seat to someone else who was happy to note down their 
 contrasting impressions of the different comb/harp assemblies, as the 
three  remaining testers were.


But the three uniform testers decided to stay and sit it out, and I  fully 
accept their scoring was sincere. After a week of reflection I've gone  from 
being highly pissed off with them to thanking them, as I can now see how  
useful and valid their contribution was. It makes me realise we set our 
sights  too low in accepting a stock nailed Marine Band as the benchmark for our 
test  harp, and should have aimed far higher.
 


The whole aim of our test was to record player perceptions of the  possible 
effects of differing comb materials. If the mating surfaces of the  
reedplates and comb were not perfect, whatever effects there could be would be  
minimised or masked entirely. This is what the uniform testers said, and I  
entirely agree with them. While I don't accept the assertion that the combs 
were  not flat (they were checked against the light with a steel ruler), it's  
undeniable that the overall assembly was not perfectly airtight, as can be 
heard  in the sound clips.


Though Vern may disagree, personally I have to admit that our test  (while 
well-intentioned and the product of lots of hard work from both of us),  
missed the mark in its most critical element: the test harmonica. It did not  
provide the required level of perfection in the seal between comb and 
reedplates  that was required to test the issue that we were aiming for. If a comb 
is not  seating to the reedplates perfectly then any possible effect from 
the comb (if  there) will be significantly reduced.


We have to thank the uniform scorers for being honest about that,  and I 
sincerely apologise for initially disparaging their scores. Instead of  
testing an assembly at the level of a stock harp, to really look at this  question 
it should be done with a test harp that adheres to the level of a top  
custom diatonic, with its superb level of airtightness between comb and  
reedplates. As one of the scorers said "I would like to see results from combs  
that are precisely flat and with plates that are properly set up."



I'd like to see that test happen too. It would take the close  involvement 
of a top custom harp maker to create the assembly and check it  constantly 
throughout the test, so there could be no quibbles from the test  players.


Though I now feel our test was fatally flawed and therefore  inconclusive, 
I belive Vern and I have contributed a lot in working out useful  procedures 
that can be used in such a future test. They are recorded in the  
Instructions for Testers on the SPAH Test webpage.


I want to warmly thank everyone who took part in this test: Vern,  Chris, 
Brandon, Cara, Alex, Jimi, Dave, Winslow and Michelle. Despite the  
difficulties and stresses, we had quite a few belly laughs in those two hours,  and 
invented a new scientific measuring guage: The WINSPAN! Who knows, it could  
be our most lasting legacy...
Brendan Power

WEBSITE: http://www.brendan-power.com
YOUTUBE:  http://www.youtube.com/BrendanPowerMusic "
********************