Re: [Harp-L] Re: breaking in new harps

[Vern <jevern@xxxxxxx>]

In modern cars, the engine has been run at full power before installation in the car.  Years ago, the engine needed time for the oil to flush out debris and wear off the rough spots.  It had nothing to do with changing the properties of the metal. See 
http://en.wikipedia.org/wiki/Break-in_(mechanical_run-in)

Metal doesn’t “become accustomed” to anything by changing its properties.  This seems to be an unwarranted analogy to muscles.  Metal fatigues with stressful cycling as microscopic cracks propagate along grain boundaries.  This is a very slow process that is unaffected by gentle “breaking in.” Gentle break-in may delay the fatigue process for at long as it lasts but does not fundamentally alter the metal.

It is harder for a reed to open than to close because it enters the slot at a different point in its cycle and, in bending, it is being forced to vibrate at other than its natural frequency. This is less efficient at causing vibration.  An opening reed won’t start to vibrate unless it is part of a system with a closing reed in a resonant embouchure. (Close gapping of opening reeds moves the point of slot entry closer to the middle of the cycle where it is more efficient.)   Otherwise, diatonic harmonicas would require valves because all of the reeds would respond to blow and draw.

Vern


On Sep 23, 2014, at 12:32 AM, Steve Baker <steve@xxxxxxxxxxxxx> wrote:

> In the Harp Handbook (1990) I described the phenomenon of closing and opening reeds, complete with illustrations. Which end of the reed the airstream comes from is not important, rather which side of the reed plate. It's harder for a reed to open than to close and it's conceivable that the material takes time to become accustomed to this.
> 
> On 23.09.2014, at 08:17, Rick Dempster wrote:
> 
>> I have yet to read why a reed plays a semitone higher when the air is travelling from the tip to the rivet end (ie a 'bend' either conventional or 'overbend' - same thing anyhow)
>> rather than the 'natural' function (ie blow reed acting as a blow, draw as a draw) where the air travels from the rivet end to the free end. In my minds eye, I see the 
>> breath starting from the rivet end being a gentler process, involving the whole length of the reed from the start of the action, whereas
>> the breath hitting the free end first might not be inclined to involve the whole reed down to the rivet, so the active portion of the reed is shorter.
>> Probably nonsense, but I've ead nothing better.
>> Dunno how, but I see this as connected to the 'breaking in' topic, of which, by the way, I am, after forty-odd years, completely undecided.
>> RD
>> 
>> On 23 September 2014 04:33, Steve Baker <steve@xxxxxxxxxxxxx> wrote:
>> On 21.09.2014, at 22:32, Robert Hale wrote:
>> 
>>> The reed is a metal spring. Takes x-number of flexes before it fails. Degree and duration of bends are additional variables, too.
>>> 
>>> ANALOGY
>>> I've never been asked to drive my new car "gently on the springs" for the first few miles.
>> 
>> Maybe not, but hopefully you've been advised not to push the engine too hard for the 1st few miles. I stand by my experience as stated and have no doubt that it takes a while for certain aspects to optimize. With new harps I find OBs tend to be more prone to squeaking and generally more difficult to hit and control. After playing for a while this improves. Most guitarists ain't too keen on brand new strings either. In both cases this may be due to the gradual build up of dried bodily secretions ;-)
>> 
>> Steve Baker
>> www.stevebaker.de
>> www.european-music-workshops.com
>> www.harmonica-masters.de
>> 
>> 
>> 
>> 
>> 
> 
> Steve Baker
> www.stevebaker.de
> www.european-music-workshops.com
> www.harmonica-masters.de
> 
> 
> 
>