 The Clarinet BBoard
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Author: Tony F
Date: 2015-11-01 15:04
Hi,
I'm having some trouble setting up the register key mechanism on a Bundy/Buescher bass clarinet. It has the single key with a plastic rocker. I'm pretty sure that it works on the principle of a strong spring balancing a weak spring, but I'm not sure which spring is stronger, which weaker and by how much. There are no leaks (now!) and it plays fine in the chalameau register, but attempts to play in the altissimo result in squeaks and squeals which are driving my cat insane.
Can someone give me a thumbnail sketch account of how it goes together?
Thanks.
Tony F.
Post Edited (2015-11-01 15:04)
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Author: clarnibass
Date: 2015-11-01 15:58
Do you see a mechanical problem causing the squeaks or do you think there is a problem just because it is squeaking? If you are not sure then check by pressing the register keys closes when they should be, to make sure this is causing the problem.
I know it's nice to get a "recipe", but I really suggest to try to solve it yourself some more before that. Analyzing the mechanism to understand how it should work and why it's not working is one of the better things you can do to improve in repairs.
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Author: Hank Lehrer
Date: 2015-11-01 16:33
Hi Tony,
I agree with the advice you got from clarnibass and have just a couple of additions. Having owned several bass clarinets over the years and being a curious individual, trying to figure out the mechanics is a sound approach.
The register mechanism on each of the instruments I have owned is different. But you are dealing with a single register key on the Bundy so that makes things a little easier. However, what you are describing may not be a register key problem but a leaking pad in the upper section. The leak could very well be acting just like an altissimo fingering. Have you checked the seating on each pad? Also, you may have a mouthpiece/reed/embouchure issue although I am leaning toward a small leak.
Good luck.
HRL
Post Edited (2015-11-01 18:03)
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Author: Steven Ocone
Date: 2015-11-01 19:32
There is one register hole for the clarion notes. This is the small one at the top. When this is open the larger hole below should be held closed by the thumb F/C key. Most often this is with a screw, though on older instruments it may be done by adding some material between the mechanisms. Too much turn of the screw and the thumb pad will not close and you will have the same symptoms.
Before you take care of this make sure that the thumb pad and the F# pad that it closes, close simultaneously. (We are assuming that both pads are level and sealing with minimum pressure). Then you are ready to adjust the register mechanism as described above.
Any leak or mis-regulated keys can create squeaks and squawks, but bass clarinet register mechanisms ARE notoriously fussy and worth understanding if you play the beasts.
Steve Ocone
Post Edited (2015-11-01 22:10)
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Author: saxlite
Date: 2015-11-02 06:15
Bass clarinet register key mechanisms can be very perplexing. Steve Ocone's description for single key mechanisms is very good. I just finished adjusting a nice 50's era Selmer Bass witha dual key mechanism-it worked fine before my tinkering, but the force required by the right hand third finger which causes the switch to the body register key was way too high, making it hard to play a smooth ascending scale over the break. It took quite a bit of thought and fiddling to get all this to work correctly, but it all works well now and the key forces are much more balanced. So, as has been said above, try to analyze the purpose of the various springs before you tinker!
Jerry
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Author: Chris P
Date: 2015-11-02 06:32
The plastic rocker is only there to apply equal pressure from the thumb key to make sure both the speaker vent pad (upper one) and the throat Bb vent pad (lower larger one) are both closed when the speaker key is released. It also allows for more venting for either of the speaker vents when it tilts as opposed to having a single fixed arm on the end of the speaker key to hold both closed.
The best way to get the adjustment right (assuming all the pads are seating properly) is either to wedge the speaker key open or remove it completely. Then you have both hands free and can easily check the closure of the thumb plate pad along with the closure of the throat Bb vent and the closure of the speaker key vent (upper one) when the thumb plate is released.
Only one of the vents should be open when the thumb plate is open standing (upper vent closed, lower vent open) and with the thumb plate held down (upper vent open, lower vent closed).
The speaker key itself is there merely to release the vent pads when it's operated, but not to determine which vent is open or closed at any one time.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: donald
Date: 2015-11-02 13:00
Hi- I have been teaching a student playing one of these basses... as far as I can tell, if it works in the chalumeau, and works in the clarion/upper register, there's no reason that it would be the register key causing problems in the altissimo.
On my student's Bundy Bass there is no change in function of the register key from clarion to altissimo register.
My experience is that the least stable notes on the bass are E and F in the clarion register, and a problem with the mechanism would make these notes noticeably difficult to play, but you report no problem with the clarion register.
I hope this was helpful
dn
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Author: Chris P
Date: 2015-11-02 13:16
On student level basses you only have the upper vent open for all the upper and altissimo register (as well as uncovering the aperture on the LH1 fingerplate for some of the lower altissimo instead of lifting LH1 off completely) as the upper vent is open while the left thumb is held down on the thumbplate.
On pro level basses the lower vent is open either when the speaker key and throat A key are both open together (for throat Bb) and also while RH3 is held down along with the speaker key. Releasing RH3 with the speaker key held down will actuate the switchover from lower to crook key vent so it's open from upper register E upwards. But the upper E, F and F# are seriously compromised (especially when slurring from throat A up to F#) as they need an extra vent in between the crook key vent and the throat Bb/lower speaker vent.
Fully loaded Oehler system basses have a fully automatic triple speaker vent mechanism whereby the lower vent is open from throat Bb to upper Eb, the middle vent is open from E to G# which clears up the dodgy F and F# and the crook key vent is open from upper register A to C. But it's a pretty complex mechanism that needs to be made and set up absolutely spot on in order for it to function properly.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
Post Edited (2015-11-02 18:52)
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Author: Tony F
Date: 2015-11-02 18:45
Thanks for your responses, Gentlemen. Donald, I've led you up the wrong path, I had a slip of the brain and actually meant that it squeals in the clarion register. That is, it did. I think I've got a handle on it now, everything seems to do what it is supposed to and it now sounds pretty good. Problems were mainly concerned with unbalanced springs and some physically bent keywork. Thanks for your description, Chris, it made the whole process easy and helped me to understand the functions and interactions of the various parts.
Tony F.
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