Pad hole depth - Now with Pictures

[Clive Thorne]

Inspired by the tread about pad holes tapered on the reed side to ease any airflow constriction over the clamp/screw assembly:

 

What effect would having a deeper hole have on tone, if any? The reason I ask is that, according to Colin Dipper,the "Drone" button ony my concertina would have originally had novelty effects on this button. These were long gone by the time I acquired it, so I got Colin to fit reeds for me.  Anyway the hole for these reeds actually goes through the thickened area of the action board, where the rest of the buttons reside, so rather than the hole being say 3mm deep it is more like 6 or 7mm deep.

 

Now the notes on this button work, but they have always been a bit "muffled" and less bright than the other notes on that side.

I gather than inboard reeds generally do sound a bit different to the peripheral ones, and there's nothing I can do about that aspect, but will the deeper hole also affect the sound?

 

Would opening up the underside of this hole, either tapered or stepped, help at all?

 

What do you all reckon?

 

 

Edited March 31 by Clive Thorne

[Jake Middleton-Metcalfe]

It is really hard to tell what the effect of opening up/counter boring/flaring the underside of the hole would be without doing an experiment. What thread did you see about that, I must have missed it? Could you post a link? I would be very interested to read it. 

 

I never experimented with this but I have seen it done on some Jeffries concertinas. The person who is most likely to have experimented with this is probably Colin Dipper. I only make that as a guess as he has tried many things over the years.

[Alex West]

4 hours ago, Jake Middleton-Metcalfe said:

Could you post a link?

Jake

 

Here are a couple of threads - there may be more...

Alex West

[Clive Thorne]

That's the one that inspired my question Alex. Thanks for locating and pointing to it.

[Chris Ghent]

While the inboard nature of the reeds probably accounts for the muffled sound it is also possible the chamber is not big enough.  Novelty noises did not have much of a chamber and creating one big enough for reeds may have been tricky.  Easily assessed by looking.  I imagine Colin took this into account.  

[Jake Middleton-Metcalfe]

2 hours ago, Chris Ghent said:

While the inboard nature of the reeds probably accounts for the muffled sound it is also possible the chamber is not big enough.  Novelty noises did not have much of a chamber and creating one big enough for reeds may have been tricky.  Easily assessed by looking.  I imagine Colin took this into account.  

 

Yeah I agree the inboard reeds always sound a bit different.

 

It's quite interesting to consider that the people in that Jeffries workshop would have known something about flaring the air holes like that and known what the result would have been. It's just one of those bits of information that hasn't really been passed on. 

[Clive Thorne]

Thanks for your thoughts folks.

Since I've had the end off for something else I have taken some photographs.

 

A few things to point out:

The hole for the drone button is actually 4 or 5 times the depth of the standard reeds.

The In 'chamber' reed on the "Drone" is only slightly recessed and secured in/on by woodscrews, so the top of the reed clamp is much closer to the sound/action board than in the outer reeds.

The reed clamp on this reed is directly under the pad hole, so, possibly restricting airflow. Unfortunately not possible to show in a photo.

 

I must admit that I'm very tempted to go ahead and do a bit of carving - on the basis that it won't make things worse, and could improve things.

 

Any further thoughts, anyone?

 

Edited March 9 by Clive Thorne

[alex_holden]

I suspect that pad doesn't lift very high when you press the button.

[Clive Thorne]

Thanks Alex.  I can see why you think that but I think the photo is deceptive because it lifts about the same as all the other pads - at least on the side furthest from the pivot. With a short lever like that the side nearest the pivot does lift noticably less. However a good point and I will take one of the cushion rings out and try it before I get carving.

 

I seem to recall that if I had just one ring fitted then the  button would tend to stick down (which is a different problem) - but I'll definitely try it again.

[Clive Thorne]

Well, following Alex's comment ,I've taken one of the cushioning rings out. It is possibly a bit better, but not dramatically. It's very hard to judge because by the time you've taken it apart, removed the ring and put it back together You (Well I) have forgotten the detail of how it sounded before.

Possibly the Pull C is a bit better, but the Push Bb, if it is better, still has a long way to go.

 

I think I'm going to try a bit of carving and will report back.

 

Edited March 17 by Clive Thorne

[Clive Thorne]

Well, I've done the carving, and it really has transformed it !!! 

 

Pull C on the drone is almost indistinguishable from the push C on the C row, and the Bb on the drone push is very similar to the Bb pull on the third row.  No more difference really than between pushing and pulling the same notes anywhere else on the instrument. Both notes distinctly more open sounding.

 

It would suggest that the original 'muffled' sound was more to do with the clamp mechanism of the "In chamber" reed retricting the airflow - as per Geoffrey Crabb's treatise, than the depth of the hole (although the mod has also reduced that depth on one side of the hole.

 

I am really happy with the result.

 

[Alex West]

8 hours ago, Clive Thorne said:

Well, I've done the carving, and it really has transformed it !!! 

Can you show a picture of what you've done Clive?

 

Alex West

[Clive Thorne]

Pictures: Apologies  for the delay.

 

It is actually quite difficult to capture the "after" satisfactorily in a photo, because the carved parts are largely the same colour as the uncarved parts. The white crescent in the after shot is where the carving has gone into the underside of the pin hole board. 

 

You can see that the hole was already quite messy before I got at it.

 

 

BEFORE:

 

 

 

 

AFTER: