Re: Soaking test results

[Mike Curtis <wd6ehr@xxxxxxxxxx>]

> At 12:42 AM 3/23/95, Mike Curtis wrote:
> >I did a scientific test
>
> and RKT replied:
> 
> Seems to me that this test loses some credibility and the results are
> somewhat dubious since a machine wasn't used to blow air into the harmonica
> at a constant velocity. When a human is used to generate air flow, the test
> becomes approximate at best. Maybe +/- 10dB. It's not much different that a
> friend of mine listening and saying "sounds like a 10dB increase to me
> Bubba." A lot of objectivity gets lost.

I never said it makes it louder at a constant wind velocity - just that 
it makes it louder when I blow on it as hard as I can while still getting 
sound.

> I'm sure that many of the rocket and other scientist types that frequent
> this list would be quick to point out that this ~scientific~ test didn't
> quite follow all of the guidelines of the Scientific Method.

Maybe I didn't use a lab standard mic or measurement standard, but that is
not required for a scientific test of this nature.  I did a test that
proved that I can make a wet Lee Oskar C harmonica produce a maximum SPL
on the blow 10 that's about 5 dB better than a dry one, according to my
Tascam 244.  As to exactly how accurate the dB measurement is, I've not
bothered to calibrate it.  

But the whole point is, it IS measureably louder. 

Besides, machines don't play the harp - people do.  The most scientific 
test involving apparatus centering on humans will involve humans.  I'm 
reasonably certain that many of us don't particularly care what a machine 
can do with our harmonicas :-)

> I'm not questioning the results or the premise. It's just that the setup
> used for this test lends itself to subjectivity and error, thereby
> essentially making the results meaningless and the question still
> unanswered.

The results proved that Mike Curtis blowing as hard as he can on a wet C
Lee Oskar with windsavers can produce a blow 10 note 5 dB hotter than a
dry one, according to the VU meter on his Tascam 244.  Nothing more;
nothing less.  I ran the test twice, and obtained repeatable results. 

Of course, I'm sure that anyone seriously questioning these results would 
have tried this experiment themselves, just as I did when I saw a test I 
questioned.  When I went into my test, it was with an open mind, and I 
was prepared to explain my findings regarding volume, even if it showed 
that the increase was in my mind.

But I will admit I was pleased as could be when I read +5 dB for the 
dripper :-)

> Besides, the test isn't repeatable. I can't blow as hard as Mike. If I
> could, I'd have a couple of 8K posts/day too.       :-)

Funny "bigmouth Mike" joke noted and laughed at (really!)

I don't use wind to type.  Too bad - it'd save wear and tear on the old 
fingers :-)

But seriously - I'm sure you can blow hard enough to "max out" the harp.  So
yes this test is indeed repeatable, by anyone with a microphone and tape 
recorder or other device equipped with a VU meter - and of course a harp 
that isn't afraid of water :-)

> And, as has been pointed out by several prominent Harp-ler's, soaking harps
> is not a good idea.

I never said it was a "good idea", either.  In fact, it's probably a 
terrible idea for most harp players, especially those with more than a 
half dozen harps they play all the time (ergo would soak all the time and 
replace all the time.)

But that's not the topic at hand.  My test was in response to the thread 
asking if soaking harps increases volume - a very simple and basic 
question, and one deserving of a simple, nonreligious answer :-)

> It certainly is NOT a solution to feedback problems as
> was implied. But, if you have deep pockets and like hanging out at the harp
> counters of music stores or by the mail box waiting for the next shipment
> from Kevin, soaking harps can be very productive.    :-)

Let's examine this scientifically:

Feedback is a sole function of amplification, speaker, and microphone. 
Assuming these are constants, and set to maximum volume with no feedback,
we may proceed to the harmonica itself. 

If the harmonica lets you play louder with the same volume setting, it
will give you that much more volume without increasing feedback threshold. 

If we assume all reeds are increased by +5 dB (which I didn't test - I
picked the 10 blow at random), that translates directly into +5 dB at the
loudspeaker, assuming you're running your amplifier linearly.  If you're
overdriving and don't compensate, the extra 5 dB will be "eaten up" as
overdrive rather than volume. 

Assuming you have, let's say, a 100 watt harmonica amp, and a "normal" 20
watts of harmonica signal with a dry harp, we would therefore expect a 5
decibel increase, or 63.24555 watts - with NO increase in feedback!

So the bottom line is, if it makes it louder without increasing amplifier 
gain, it will help with feedback if that's a problem.

However, the most compelling reason not to play wet harmonicas is the 
electrocution factor.  If you've even gotten "bitten" by your harp mic, 
it will be FAR worse if your hands are wet.  If you use a wireless, this 
potential is eliminated.

And yes, electronics buffs, that is a pun :-)  (Potential is another word 
for "voltage")

I think we all agree that soaking harps is not good for them and you'll 
get less life from them if you soak.  I think we also agree that soaking 
wooden comb harps causes swelling of the comb which can be painful and/or 
hazardous.  In my post, I put that at the very beginning.  My test had 
absolutely nothing to do with that.  It had to do solely and exclusively 
with absolute loudest obtainable volume of "dry" harps compared with 
"wet" harps.  I hoped I had made this perfectly clear in my detailed 
explanation.  If not, I hope it is clear here.

Bottom line: I really don't care if you soak your harps or not.  If you 
do, they won't last as long, and you run the risk of fatal electric shock 
if you use a straight mic and cord.

Actually, from my findings, a quick dip in cold water is as effective as 
soaking, and the effect seems to last as long.

This all began with a question asking whether soaking could be used 
to increase volume.  The simple answer to this simple question is "yes".

I welcome others to do testing of their own should they desire and post 
to the list.


 -- mike