Split reed plate

[sven6side]

My first post.

Thinking of building an Anglo. Have plenty of PA reeds. Which is best:
1 Split the plates lengthwise and only use 1 reed
2 Use both reeds and tune the other one up/down.

[ttonon]

Hi Sven,

 

Most the PA reeds I've seen have the heel of the tongue, which is spring steel, extend past the midpoint of the plate.  One tongue on each side of the plate.  In order to split the reed, it would be simplest to cut the whole thing lengthwise with a carbide tool.  But the cut must be pretty thin (it's kerf), and I'm not aware of carbide cutting wheels that thin.  

 

Alternatively, you'd have to take out the tongues, cut the aluminum plate, grind down one side of the tongue heel, then re-assemble.  A lot of work.  

 

I think your second option is much easier.  There could be a question of how much the tone is affected by moving the pitch so much.  My guess is that this issue is much less with raising the pitch than with lowering it.  Raising the pitch requires removing mass near the tongue tip, and lowering it requires removing mass from the heel end, which I believe affects dynamics much more.  I'm sure others here have more experience with that.  

 

I haven't checked, but there might be clever ways to choose what PA reed to use for a particular cavity.  For instance, there may be PA pitches that would allow tuning both tongues, which would require less of a pitch change for the tongue whose pitch must be lowered.

 

Best regards,

Tom

www.bluesbox.biz

[alex_holden]

I think @Pistachio Dreamer uses retuned accordion reeds in his Duckling Anglo concertinas.

[Pistachio Dreamer]

On 9/30/2022 at 10:42 AM, sven6side said:

My first post.

Thinking of building an Anglo. Have plenty of PA reeds. Which is best:
1 Split the plates lengthwise and only use 1 reed
2 Use both reeds and tune the other one up/down.

Thanks Alex for the nudge, and apologies to the OP I'm not on here that often!

 

I go with 2 as a rule, as it's very easy to weight and drop the pitch of one of the reeds. I choose the plate for the upper note I want to use.

 

I did use 1 as a method for an instrument I have just completed in a limited case. This was an instrument using hohner brass tongued melodeon reeds, a GD. In order to get good response from the lowest G/D reed I paired a cut bass reed for the G with a cut tenor reed for the D. The chamber design was more complicated, but it worked well.

 

Hope that helps,

Paul.

[Pistachio Dreamer]

I should also add that you can usually only use one of the reeds on the plate using method 1, and lose the other, as there is not enough room to make a cut that preserves integrity and clearance for both reeds.