Re: [Harp-L] piezo and magnetic pickups

["Vern Smith" <jevern@xxxxxxx>]

Most stainless steel is not magnetic.  The type that is 
magnetic is the heat-treatable kind that is an unlikely 
choice for harmonica reeds.  The other way to energise a 
magnetic pickup is to pass an electrical current through the 
string or reed.  Unfortunately, there is no way to pass a 
current through a reed because the vibrating tip is not 
accessible for an electrical connection.

I posit that the signal from a magnetic pickup would not 
sound much like a harmonica.  The pickup would sense the 
smooth, sinusoidal,  mechanical motion of the reed.  The 
signal would not have the overtones that a harmonica sound 
does.  The reed tip opens and closes the slot in the plate 
in a very abrupt and non-linear fashion.  The effect of this 
variation in area on the airflow generates the overtones 
that are characteristic of the harmonica.  I doubt that the 
sound would be much affected by hand-cupping.

Making a magnetic pickup for a harp would require making the 
reeds of magnetic material and a large and expensive  coil 
or set of coils.  For the reason given above, I think that 
the sound produced would be disappointing.

I believe that a better mic for the harp is like the ones 
used by Mike Curtis and Paul Oscher for neck-rack use.  The 
back of the harp adjoins an opening in the side of a 
cylinder with a mic element in one end.   The sound of all 
the reeds is "captured" in the cylinder and picked up by the 
mic element.  I am currently using such a mic-in-a-can that 
I like very much for use on my Ergonomic-Neck-Rack.   Such 
mics/pickups would not be the choice of  most players who 
hold their harp in their hands and make "wah-wah" sounds 
with their hand cup.

There is someone out there who has tried it.  A few years 
ago, I made a reedplate with a few clockspring-steel reeds 
for someone who was experimenting with a magnetic pickup.  I 
forget who it was.  I never heard back from him about any 
results from his work.

Vern

----- Original Message ----- 
From: "Björn Sigurdsson" <bjosi436@xxxxxxxxxxxxxx>
To: <harp-l@xxxxxxxxxx>
Sent: Wednesday, March 18, 2009 3:12 PM
Subject: [Harp-L] piezo and magnetic pickups


Hello again, if you mail one mail to harp-l, it is so easy 
to mail one more.
Many of you just love to discuss microphones... I read and 
learn....

BUT WHAT ABOUT playing with piezo-pickups (for example check 
out
http://www.kksound.com/hotharmonica.html) COMMENTS, PLEASE!

Or whatabout my own idea:  mount an over sized MAGNETIC 
PICKUP on an
seydel 1847 - I assume this should work!? Reeds of steel. I 
can not
find any
information about someone tried this, but it would surprise 
me if no
one have tried it! Steel strings... steel reeds... it is a 
very
natural thing to think, so I guess I have to miss something 
here?
I assume people working with the development of 1847:s have 
tried
this. What is the hatch? Next time I see an electric guitar 
I will
just hold it close to a magnetic pickup and see what 
happens. And if
this work, what do You think of placement. Will the covers 
interfere
if you place it on a cover. Most easy and out of the way of 
course is
to fasten a pickup on the back of the comb. But I know that 
magnetic
pick ups have a hard time to pick up bowed string sounds 
because the
string moves wrong (parallel to the pickup?) and in analogy 
with that
this maybe is a suboptimal placement? COMMENTS ON THIS?

--
Må Väl / Kind Regards

Björn Sigurdsson
Kompanigatan 20
58758 Linköping
+46 706 897257

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