RE: [Harp-L] Re: Customizing XB-40

[Steve Shaw <moorcot@xxxxxxx>]

Speaking of low-keyed XB40s, and while I've got you here, Rick ;-) I have a slight issue with 6-blow on my low D XB40 that has so far eluded my usual resourcefulness. If I play the note at moderate volume, all's well and good, but give it a bit more welly and the note starts to sound squawky and goes up slightly in pitch. The harp has been like it since new about four years ago. Like all the best surgeons I tend to go for the least invasive investigations first, but I think I need to get a bit more radical to solve this one...do I?
Cheers
Steve 
> There is a modification that I do with the combs of my low-keyed XB-40s.
>  Even though the XB-40's reed cell clearance is the same as that for the
> Super Chromonica, which has the same reeds,  the responder reeds give the
> XB-40's regular reeds an extra boost, so that they swing farther than Super
> Chromonica reeds - so much so that the lowest reeds may strike their cell
> floor if played with enough force.  I chisel away some of the cell floor
> from under any problem reeds to give them a little more clearance.  This is
> not something that could have been taken care of in the comb's injection
> mold, because all the parts of the comb must be of similar thickness to
> avoid irregular shrinkage of the ABS plastic as it cools after removal from
> the mold.  But there is no problem with thinning a reed cell floor on a
> finished comb.  If you should chisel away too much and break into the
> middle valve cell, the hole can easily be filled with ABS shavings melted
> into a paste with acetone.  Just be careful not to chisel away any area of
> a cell floor that lies underneath a reed valve.  This modification allows
> me to get more volume out of the low notes of the low keys, without the
> reeds rattling against their cell floor.
> 
> Best regards,
> Rick