Weak Notes

[varney]

I've finished a couple of Lachenal anglos recently and am happy overall with the results. However, there are a couple of notes on each which are slightly 'weak' in comparison to the others. It's not easy to describe but generally they don't have the same 'oomph' as the rest! Just noticeably lower in volume and somewhat dullish in sound.

 

I've checked the reeds are seated properly - neither too tight or too loose - in the slots, swapped valves, cleaned the tongues, tried slightly different settings for the tongues, but in the end they just remain pretty lacklustre.

 

Any suggestions on what else could be tried, or is it a case that they just need to be swapped out?

 

Michael.

[RAc]

I've finished a couple of Lachenal anglos recently and am happy overall with the results. However, there are a couple of notes on each which are slightly 'weak' in comparison to the others. It's not easy to describe but generally they don't have the same 'oomph' as the rest! Just noticeably lower in volume and somewhat dullish in sound.

 

I've checked the reeds are seated properly - neither too tight or too loose - in the slots, swapped valves, cleaned the tongues, tried slightly different settings for the tongues, but in the end they just remain pretty lacklustre.

 

Any suggestions on what else could be tried, or is it a case that they just need to be swapped out?

 

Michael.

 

Have you checked the chamois gaskets between the reed and action pans? I could imagine that very slight air leaks (for example in the walls between the chambers and the centre hole if the thing does not affect adjacent chambers) may weaken the sound. Does the problem occur on both notes on the same button, or only on individuals?

 

Just a wild guess...

[Theo]

Yes it could be internal air leaks, also check the reed pan support blocks are all solid, and are holding the top of the reedpan flush with the top of the bellows frame. Also check for gaps between the sides of the reedpan and the bellows frame, the reedpan should be a very snug fit. Weak notes can also be caused by valves that are too thick and are not opening fully. If all these sort of causes can be eliminated then it may just be that they are duff reeds, perhaps replacements of a lesser quality from the originals.

[malcolmbebb]

I have a 20k Lachenal with brass reeds. One note is noticeably quieter and slower to sound, and breathy. On inspection there is a bigger gap on this reed between the end of the reed and the shoe.

 

I would guess that this is the cause of the problem - valves etc are new and the box has been recently tuned. Any thoughts on whether this is fixable, or whether I should be thinking of replacing it?

 

It's the push B or D on the right G row. Not an area where I like to spend much time, but needed for a tune I'm trying to learn.

[Theo]

If the clearance at the edges of the reed tongue are similar to the other reeds then it might be worth re-positioning the tongue to take up the gap at the tip. Be warned though it can be very frustrating trying to get the reed clamped centrally and sounding cleanly.

[Frank Edgley]

It sounds like the reed chamber is probably not completely airtight, allowing some of the air to leak out of the chamber and not go though the reed.....not all that uncommon with Lachenals. It could be the gasket at the top of the dividers too low, space between the bellows frame and reed pan, a space occuring because of warping of the reed pan and / or mating suface of the action board, or all of the above.

[varney]

Thank you all for that spot on advice.

 

One problem note was in a corner where the support block is just a tad low, but I'd overlooked this. And the other did have a small gap between pan and frame. Tackled both and now they're all playing to their full potential.

 

Great to get so many helpful answers -- that's why I love this forum... thanks guys!

 

michael.