Re: [Harp-L] re:What Cover-Plates Don't Do

[Tom Martin <tomdmartin@xxxxxxxxx>]

I have a question about cover-plates...does anybody know of any place that
will customize a cover-plate?

Tom

On Thu, Jan 17, 2013 at 12:55 PM, Mike <mikefugazzi@xxxxxxxxx> wrote:

> I don't have any, but it would be very interesting, IMO, to add to the
> complex question the impact of things like powder coating on timbre.  Are
> you talking about the SPAH test?  The best way to do any of these, IMO, is
> to remove the human element.  I need one of those music store testing
> things.
>
> On Thursday, January 17, 2013 11:42:57 AM UTC-6, Jonathan Ross wrote:
> >
> >
> > > I am NOT being snarky, but have you experimented with this regarding
> > measurement?  There have been a couple of threads recently where theory
> has
> > been applied to what can/can't happen with a harmonica, but I am unaware
> of
> > even any anecdotal evidence describing this in the real world.
> >
> > The best evidence has been the attempted tests on comb materials.  No
> > other attempts at real testing have been made public.  I have not tested
> > any of this beyond listening trials.  They are not capable of proving
> > anything, except giving a hint.
> >
> >
> > > I readily admit to trying to measure some of these things but with
> > limited expertise in using tools.
> >
> > Frequency analysis can be useful, but different readings can have
> multiple
> > causes.  I am sure Vern would have more to say on this, but just because
> a
> > difference is notes by a machine doesn't mean it would be noted in
> practice
> > by listeners or players, for instance.
> >
> >
> > > The changes in volume were the most obvious, but the sound pictures
> were
> > different too.  I used a stock A Crossover and rotated between stock MB,
> > XO, and SP20 covers.  This was for my own amusement, so I didn't fret
> > recording things or logging pictures of the frequency responses, etc.
> >  There are SO many variables to consider that at its most basic interest,
> > regardless of the how, I can personally conclude that open XO style
> covers
> > are my favorite.  MB covers that are opened would work too.
> >
> > Lots of variables come into play.  Perhaps the most important one is the
> > player.  I feel confident in saying that no matter how hard you try, if
> you
> > know the covers are different you will play differently.  I would
> eliminate
> > either the player entirely or blind test everything--where you can't tell
> > which covers are being used.
> >
> > > While I felt SP20 covers felt more comfortable and besolid, the sound I
> > was hearing when playing was warmer and less present at both the same
> > playing pressure and volumes.
> >
> >
> > I have a brass combed MB which I love.  I often feel that it sounds
> > different from a similar one with a composit comb.  But, when I listen
> > closely to the two and try to ignore feel issues, the timbre is
> unchanged.
> >  Granted we are discussing covers not combs, but the point is that my
> ears
> > can be fooled into hearing what they want to, and I have to work hard to
> > try and get around that. I would suggest that may be the case here.
> >
> > However, if changes in timbre because of cover shape, material or the
> like
> > can be tested and found to exist, that would be interesting.  However,
> the
> > hard part then would be to figure out why, since there are at present no
> > reasons in theory as to why that would be the case.  But I certainly
> > encourage more testing--I would love an someone who actually works in
> > acoustics to get involved.
> >
> >
> > JR Ross
> >
>