Re: [Harp-L] When embossing...

[fjm <bad_hat@xxxxxxxx>]

My hypothesis is that the airflow through the slot gets changed by the 
altered shape of the slot.  Embossed slots don't have square edges. They 
have a lip at the top.  If you take a grid strainer type drain and fill 
a vessel with water the drain won't drain until the water rises to a 
level that it overcomes the surface tension around the holes in the 
drain.  That's with punched holes.  If the holes are drilled the water 
flows right on through.  The punched holes are like embossed slots in 
their shape.  Why that might alter the sound I do not know.  fjm