 The Clarinet BBoard
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Author: BbMajorBoy
Date: 2015-02-26 20:07
So I got a Selmer Low C bass on loan from my local music authority but when doing a few scales for the first time, I noticed that when I play throat Bb, both register vents open, producing a sharp Bb and a flat B.
What do I need to adjust?
Ill add pictures in a minute or two.
Leonard Bernstein: "To achieve great things, two things are needed; a plan, and not quite enough time."
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Author: BbMajorBoy
Date: 2015-02-26 20:14
Images
Leonard Bernstein: "To achieve great things, two things are needed; a plan, and not quite enough time."
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Author: BbMajorBoy
Date: 2015-02-26 20:14
Attachment: DSC_0675.jpg (1194k)
Attachment: DSC_0674.jpg (1913k)
Images taken while pressing down A key and 12th key.
Leonard Bernstein: "To achieve great things, two things are needed; a plan, and not quite enough time."
Post Edited (2015-02-26 20:17)
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Author: Chris P
Date: 2015-02-26 20:16
I'd say your best bet is to play it safe and have it repaired at your local education authority's expense.
Are you in Bookham in Surrey? I don't know if Peter Eaton tackles repair work on instruments other than his own make, but he's the only clarinet specialist (and maker) in that area.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
Post Edited (2015-02-26 20:17)
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Author: BbMajorBoy
Date: 2015-02-26 20:26
No, Im in South London.
What needs to be done?
Ive overhauled sopranos before but never really adjusted a bass.
Leonard Bernstein: "To achieve great things, two things are needed; a plan, and not quite enough time."
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Author: Chris P
Date: 2015-02-26 20:37
You'll end up going round in circles adjusting the speaker mechanism on a bass, but at least Selmers (and the current Buffets) have simplified the mechanism.
With just the top joint, when you press the speaker key the shift lever at the top should move. Then when you open the throat A key, the shift lever will return to its resting position and the lower vent pad should open.
Check there's a small gap between the shift lever and the crook key when you put the crook on, then check it with the speaker key held down and opening and releasing the throat A key to switch both vents. If that all works fine, then fit the lower joint and check the speaker mechanism - hold the speaker key down and only the crook key should open. Then close RH finger 3 on the lower joint and that should make the lower vent open.
Without seeing the instrument I can't really make a diagnosis of what is wrong, but I can only tell you how it should work. So check all the linkages - especially the one at the middle joint as these are the most vulnerable ones to being bent through careless handling or lack of knowledge on assembling them.
When you assemble a bass with the double speaker mechanism such as pro Selmers, Buffets and Yamahas (and others), then you have to make sure you close all the top joint fingerplates and also hold the throat A key down to raise both the linkages so they don't get mangled.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: BbMajorBoy
Date: 2015-02-26 20:52
There is no gap on the crook and the shift lever doesnt move that much.
Should both vents ever be open at the same time?
I might take it to Howarth some time this week.
Leonard Bernstein: "To achieve great things, two things are needed; a plan, and not quite enough time."
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Author: Chris P
Date: 2015-02-26 21:05
No - only one vent should be open at any time when the speaker key is held down.
The lower vent should be open for throat Bb and then upper register B up to Eb.
When you release RH finger 3, the lower vent should close fully and the crook key should open for all notes from upper register E upwards.
If both vents are open at the same time when the speaker key is held down, something is out of adjustment.
It's one of the trickiest mechanisms to adjust as you need to make sure RH3 has the correct venting, the speaker key has the correct amount of movement, the throat A key isn't holding the linkage arm under it down, the crook key isn't being held open by the shift lever, all the correct thickness key corks are in place and all adjusting screws are correctly adjusted and not missing the silencing material under them or on their tips. A fair bit of kit to understand and adjust there!
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: clarnibass
Date: 2015-02-26 21:13
>> Should both vents ever be open at the same time? <<
They might be open at the same time sometimes during the travel of the register lever, but never when the register lever is fully pressed, which seems to be the case on your instrument. One situation is when you'd play Bb (coming from e.g. open G) and press the register lever faster than the A key.
Basically, you need to figure out how the mechanism works and what any change you make does, then make the correct changes to solve the problem. Like a puzzle.
If you post more thorough photos of the entire mechanism then someone might be able to suggest what to do.
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