Did Harrison have a point

[Bill Hibbert]

I have been meaning to reply to Roderic's messages for a couple of 
weeks.

The only Harrison bells I have analysed, so far, are the eight at 
Castleton. The trebles are fairly typical old-style. The tenors are 
remarkable - roughly the samne height as the trebles, judged by eye, 
but with much wider mouths. The tenors have the same upper partial 
structure as the trebles (which is why they have strike notes) but 
lower partials which are astonishingly sharp. Some of the tierces 
are a sharp augmented fourth, almost a fifth, with primes two 
semitones sharp. Hence the unique sound.

RB> Harrison knew about [the need for large mouths to give a large 
radiating area] and produced bells with very large diameter mouths 
for the weight, they do radiate.

Actually, the large mouths are needed to get the strike pitch 
correct. The nominal, superquint and octave nominal must have 6, 8 
and 10 antinodes around the soundbow. Broadly, a longer soundbow 
circumference is needed to get the lower frequency nominal needed. 
If the bells had smaller mouths, they would have a higher pitch.

Can low-pitched light bells be designed?

AW> Handbells?

Handbells pitch by the lowest partial rather than the half-nominal, 
for physical reasons to do with the arrangement of their partials. 
Also, the much thinner wall gives a low pitch for the same soundbow 
circumference. That's why they have such a low note with so little 
metal / physical size.

RB> Computer generation of profiles ...

The ausbell work by Neil McLachlan and crew is very clever indeed 
but has different tonal objectives than conventional bell 
production. Also (based on recordings I have heard), close control 
of manufacturing tolerances would be needed to give the accurate 
partial frequencies and absence of doublets we have come to expect.

So, I suspect the answer to the above question is: no, not if you 
want them to sound like bells. Someone needs to prove me wrong and 
save us all a lot of money!

Bill H