squeaky reeds as mounted on top of the reedpan

[Wolf Molkentin]

My latest acquisition, a lovely Crabb 20 b Bb/F Anglo, has one button added on the RH side, providing the obvious B/Db (C#/Eb) accidentals. At the time being I don't use these reeds much, however I noticed their markedly inferior sound quality.

 

Apparently it's steel reeds on "dovetail" reedshows just like the original 40 reeds. However, there's one difference: the air flow is directed in a different way as they're mounted on top of the reed pan (no slot naturally, no pit in any way), and likewise on the opposite side the action board has another layer of plywood attached, resulting in a much longer resp. "deeper" windway (and a less than perfect aperture upon pressing the button too, but this alone shouldn't cause the sound issue IMO).

 

Do my assumptions about the reasons possibly causing a rather squeaky sound appear valid, can there anything be done (f.i.: reducing the wood between reedshoe and pad)?

 

Best wishes - ?

 

Edited October 19, 2018 by Wolf Molkentin

[alex_holden]

Any chance of photographs? It sounds like rather an unusual arrangement.

[malcolm clapp]

As previously noticed in the seller's photos, a good place to start might be to reduce the length of the chamber by adding another divider close to the tip of the reed shoe. And it perhaps wouldn't hurt to check that the reeds are securely screwed down....

Edited October 18, 2018 by malcolm clapp
grammar and spelling!

[Wolf Molkentin]

Thanks a lot Malcolm - I'll try that first, as it would be easily reversible and probably conducive in any event.

 

The screwing I already checked, turned out to be a bit tricky not to cause tensions which then are twisting the reed. As the clearance is tight (as it should), the reed is easily forced to touch the "wall" of the reed shoe then.

 

Best wishes - ?

[Wolf Molkentin]

7 hours ago, malcolm clapp said:

reducing the length of the chamber by adding another divider close to the tip of the reed shoe

 

acchieved in fact a huge improvement!

 

So thanks a lot Malcolm - I guess I won‘t be reducing the wood, the sound is still not perfect, but quite acceptable considering the rare use of these two notes!

 

BTW, despite my expectations I seem to need them just in the tonic of the outer row (for „Mediterranean“ consecutive thirds below the melody).

 

I won‘t change sides but stick to the EC I‘m sure, but this basic bisonoric stuff is really fun! 

 

Best wishes - ?

[Wolf Molkentin]

8 hours ago, alex_holden said:

Any chance of photographs? It sounds like rather an unusual arrangement.

 

Hi Alex, thank you for your inquiry which I seem to have overlooked earlier.

 

I hope the seller doesn‘t mind me posting crops of two of his pics.

 

Best wishes - ?

 

Edited October 18, 2018 by Wolf Molkentin

[alex_holden]

I see, yes, 'inboard' reeds can sound rather different. It's worth trying to reduce the chamber length as Malcolm suggested (as a quick check, you can fill the space with a chunk of modelling clay). Is the pad hole the same diameter as the others or have they made it smaller to squeeze it in? Where is the pad hole along the length of the chamber (we generally try to place it over the clamp end). I'm a little suspicious of the screw right at the tip of the reed frame - it looks very close to the tongue, which might be doing something to the airflow. Do the reeds look in fairly good condition or have they been heavily filed to alter their pitch? Do the vent slots in the board under the reeds look to be as large as those under other similar-size reeds? Do the valves feel to be a similar weight to other reeds of a similar pitch?

[Wolf Molkentin]

Hi Alex,

 

thanks a lot for all these suggestions!

 

The screw, to begin with, was looking dubious to me as well; first thing I fixed upon receiving the instrument was removing it from the tip of the tongue (it had just been fractions of a mm away from it, as visible from the first pic).

 

The pad hole is in fact slightly smaller (as indicated by the pad itself with its more rectangular shape), but placed over the clamp as usual.

 

Albeit I haven't looked after a note indication on the reed shoes, the reeds are looking o.k. to me, with a very tight clearance as well. The valves are like with the other reeds (there were very few valves at all, I complemented the missing, assuming no reed in a Bb/F would be so small that it wouldn't benefit from a valve; however the effect was barely noticeably; the reeds are admittedly not all too responsive (my basic Lachenal's are doing better in this respect), but have a very likable profound sound, as far away from a "hybrid" sound as possible as for me).

 

My own suspicion was in fact directed at the vent slots in the board. They are wide enough, but very "deep" with two additional layers of wood - so not just "inboard" (which I was aware of from postings by Adrian and others)...

 

However, I followed Malcolm's suggestion, and that alone caused a massive improvement, which I'm very content with at the moment.

 

I will examine the case further upon having to open the instrument the next time - these wood screws without a nut are really making me nervous (BTW, how would you estimate the effort to insert nuts for machine screws at some point?) so I try to avoid frequent unscrewing and screwing.

 

Again, thank you so much Malcolm and Alex - once more these forums have proved to be an incredible ressource of  advice!

 

Best wishes - ?

 

 

BTW: Bb/F has turned out to be a really beautiful option, at least for playing alone, song accompaniment, or possibly joining a brass band... ?

 

Edited October 19, 2018 by Wolf Molkentin

[alex_holden]

Well done, glad to hear it's sounding better now! Inserting captive nuts isn't a huge job for a restorer, particularly if you don't have to deal with removing existing nuts; the tedious part I find is removing and replacing the chamois gasket. The type of nut that looks like a knurled cylinder is easier to install than the traditional flat plate held in by two wood screws.