Re: dB SPL testing

[Barry Schaede <barrys@xxxxxxxxxxxxxxxxxxxxxxx>]

I must admit that up until now I've been a willing participant in this 
somewhat rididculous discussion on the effects of water and the relative 
volume of harmonicas the testing has led me to discover an interesting 
effect that is totally unrelated to the scuba gear for harmonicas 
thread.  While trying one last time to replicate the results of the plus 
10 dB crowd I had the following result.  Using a regulated air supply I 
found that I was unable to get lower notes of a Suzuki D harmonica to 
sound at all.  The windsavers would resonate (in fact one broke off as 
the result of my abuse) but, the reeds would not.  I did have success 
with the higher blow notes on this same harmonica.  What was the 
difference?  My initial thought was that the resonant frequency of the 
air supply I was using was to high to sound the reed.  I also had the 
thought that perhaps it was the interaction of the windsaver that caused 
the problem.  The upper reeds on the Suzuki's are not valved.  I can 
reproduce the no sound effect by blowing myself.  The funny thing about 
that is that it seems to be more of a trying to force a note to overblow 
that cannot.  That would tend to support the resonance theory.  I truly 
don't have an answer to this question but I am intrigued and welcome any 
informed input on the subject.

Oh yes and as for the results of the soaking.  No discernible difference 
in volume between a wet Suzuki and a dry one.  This using a regulated air 
supply on the number 7 and 8 blow reeds of a key of D valved Pro Master.  
I will say this, tiny differences in proximity affect the dB readings much 
more than the relative humidity of the interior of the harmonica. If 
there is a difference it's less than 1 dB and not discernable with my 
test equipment or the human ear.  The disclaimer being of course that I 
didn't go valve any of my Lee Oskars to conduct this test nor did I run 
out and buy a 4 track to measure the levels. Different methods, different 
results.  Enough already.  Sorry for the bandwidth.  FJM