One note 'after buzz'

[Beemer]

One bass fundamental note, the G above C indent button buzzes after release. This is equally loud on both bellows directions. Unlike the nice after-rumble on the lowest reeds which do not annoy me, this buzz like sound is most distracting. Since the sound occurs with either bellow direction, I would like opinions on what might be causing this and which I heard since the new Scandalli was first played in July. The dealer says this is normal, but it is absent on the other notes. Playing that G on the treble appears to invoke the buzz in the bass note.

 

[Walker]

This may not be a popular opinion, but you know Ian, it's a very new and very lovely accordion, let it settle in. Play it and enjoy it. It's easy to get very sensitive about these little buzzes and sympathetic frequencies. But I would always urge caution about sending instruments to repairers for a something and a nothing, as my old mother would call it. There's never yet been a perfect accordion made. With a bit of luck the buzz will fade and something else will creak instead, to take your mind off the buzz...

 

[boxplayer4000]

Beemer: I sympathise. It's not easy to ignore a note or key which is not behaving itself.
It's not easy diagnosing those faults at a distance but 'resonance' might be happening. ie. some other part of the accordion is 'buzzing' in sympathy with the G note sound. Try generating a G note from another source (another accordion or from a sound generator on the computer etc.) If there is a part in 'sympathy' with the sound on your accordion it will sound and it'll disappear if you touch it. If you can find such a part then it can be given attention. The problem is rare but I have noticed it with covers and grills.

 

[debra]

The dealer saying "this is normal" is standard language for "I don't want to deal with it". Something is resonating with the note and continues to vibrate after you release the note (more than the normal "growl" of bass notes. It would be hard for the dealer to find exactly what is resonating and vibrating and that's why it's brushed off as being normal, where in fact it is not normal, but could be the result of a design fault. It could for instance be a spring somewhere that resonates (like that of the air release valve or some spring in the bass mechanic). It could be a valve problem... It can be many things and the problem is likely to not show itself when the accordion is taken apart and the bass compartment placed on a tuning bellows for inspection. Finding issues inside an accordion can sometimes be a very tough detective job, and can take hours to find. Again, that's why the dealer doesn't want to deal with it despite the accordion being under warranty...

 

[boxplayer4000]

A low G note frequency is close to mains frequency as well but I don't know your circumstances regarding nearby electrical equipment.

 

[colinm]

You should be able to make a recording of the noise and post it on here.

 

[JIM D.]

In this case diagnosing your problem without examining the accordion is only guess work.
Now if I indeed have your accordion, I would first check the valves on your bass reed blocks.
A valve not closing completely will allow a heavy bass reed tongue to continue to vibrate.
In new Italian accordions the treble reed blocks now come with plastic valves. The bass
reed blocks should have leather valves and one of these might have fallen off or not closing
completely.

 

[Ventura]

well the very first step in diagnosis as taught to me
is to LOOK CLOSELY at everything related to or in the vicinity
of the problem

you just never know when simple close observation will reveal
a clue or even a solution.... like an unusual hairline stress crack in
a large circuit board of a power amp that was almost impossible to see or predict.

so open the darn thing up and figure out which Reed is the big G
and look it over with a magnifying glass.. move the reed-flap and ping it
a few times too along with the exposed reed

blow on it.. tap it gently.. and yes aim a G tone from some other device
at the exposed stuff to see if something sympathetically reacts

those Mylar flaps do tend to fall off much more often than the old
leather style (in my observation) and it could be as simple as the
inside one is dislodged and not dampening the reed

good luck and start pulling those bellows pins out

 

[boxplayer4000]

Beemer: Sounds like you're about an hour away. I'd be happy to have a look if some of the suggestions above don't help.

 

[Beemer]

You should be able to make a recording of the noise and post it on here.

Colin, Here is a recording of the G note in question but played alternately with A#. I did this as I now realise that the A# 'buzz' appears to me to be the same frequency and perhaps even louder than the G despite the notes not being musically resonant. When I first reported this to the dealer I had never played an accordion before and said that I believed the buzz to be a mechanical resonance but this was dismissed. I was not confident enough to disagree.

Scandalli g and a#.mp3 | Powered by Box

app.box.com

I intend to make a pin puller by grinding the jaws of top cutting pliers. I have read the disassembly procedure in accordionrevival and after opening I will play my other accordion nearby to see if there is any sympathetic vibration in the Scandalli. I agree with Debra's earlier comment about the tuning as Bbb is 10 cents high.

 

[Big Squeezy Accordions]

That's just the sound of the low bass reeds continuing to swing back and forth for a second after air pressure has stopped. All low, weighted reeds do this to some extent. The effect is just more pronounced in some. An accordion reed is, essentially, a Jew's harp with a very low tolerance between the spring and frame. I'm afraid I have to agree with your dealer in this case.

 

[Walker]

That's just the sound of the low bass reeds continuing to swing back and forth for a second after air pressure has stopped. All low, weighted reeds do this to some extent. The effect is just more pronounced in some. An accordion reed is, essentially, a Jew's harp with a very low tolerance between the spring and frame. I'm afraid I have to agree with your dealer in this case.

I totally agree with you BSA! But it is human nature to overthink stuff, especially beginners on new accordions.

Be happy Ian, it's a bit of bass growl.

 

[Beemer]

I totally agree with you BSA! But it is human nature to overthink stuff, especially beginners on new accordions.

Be happy Ian, it's a bit of bass growl.

Thanks to you all for your responses. I was aware of bass growl from reading old and new posts and hear it when I play the 16ft reeds. I just didn't think that the higher notes I was playing would have exhibited it. Here is a YT video I found that shows the effect on the lowest end-weighted reeds.
I have been regularly tuning acoustic pianos for seven years and this involves intense listening during tuning. This might well be the reason I am sensitive about the accordion growl.
I get happier as my playing improves!
Ian

 

[Ventura]

so we should be happy that sympathetic vibration from the low G
does not cause one of our (dental) stainless steel Crowns to buzz ?

obviously, any reed with Weighting on the tip is a compromise with
ideal size and mathematics.. just as some Piano strings are wrapped,
a reed for that frequency without weighting would be so long as
not to be able to fit inside the bellows

nevertheless, a better engineered and better made low reed will
have less grow and be more responsive then a poorly engineered one,
so i for one do not accept that a noticeable level of growl or a ridiculously
long time curve for said low reed to reach the correct pitch is acceptable.

 

[Beemer]

so we should be happy that sympathetic vibration from the low G
does not cause one of our (dental) stainless steel Crowns to buzz ?

obviously, any reed with Weighting on the tip is a compromise with
ideal size and mathematics.. just as some Piano strings are wrapped,
a reed for that frequency without weighting would be so long as
not to be able to fit inside the bellows

nevertheless, a better engineered and better made low reed will
have less grow and be more responsive then a poorly engineered one,
so i for one do not accept that a noticeable level of growl or a ridiculously
long time curve for said low reed to reach the correct pitch is acceptable.

I once posted (I don't think it was here) asking if reed designers could use a thicker reed instead of weighting the tip. I didn't get an answer but I guess using a weight favours a better reed curve during its bend.

 

[Big Squeezy Accordions]

I once posted (I don't think it was here) asking if reed designers could use a thicker reed instead of weighting the tip. I didn't get an answer but I guess using a weight favours a better reed curve during its bend.

A reed that is thicker for the entire length would not have that effect. In fact, the way you lower the pitch of a reed while tuning is to make it thinner near the fixed end. Thicker metal near the free end of the reed would lower the pitch, but that would be the same as having a weight attached. The fattest sounding, most responsive bass reeds are called helikon and are typically too large to face the ordinary direction and must be offset 90 degrees to fit. These sound great, but are not found in most accordions.

 

[Ventura]

i believe it is the length (ideal for a given pitch)
and then ideal thickness to allow the correct flex - flex/point without fracture
which results in a reed you can only find in a Reed Organ
that was manufactured by a dedicated fanatic !

which leads us to the compromise of the weighted tip
too long a weight will compromise the flex point
too short a weight would overdrive the tip into
motion that could cause anomalies (like a prolonged buzz)
as the mass closer to the tip will be harder to dampen back down

this is where the lost knowledge of the Empirics and Great
reed-geniuses like Gola is sorely missed, as the new engineers
simply do not have the time or resources (funding) to search
and experiment for the ideals

 

[debra]

Colin, Here is a recording of the G note in question but played alternately with A#. I did this as I now realise that the A# 'buzz' appears to me to be the same frequency and perhaps even louder than the G despite the notes not being musically resonant. When I first reported this to the dealer I had never played an accordion before and said that I believed the buzz to be a mechanical resonance but this was dismissed. I was not confident enough to disagree.

Scandalli g and a#.mp3 | Powered by Box

app.box.com

I intend to make a pin puller by grinding the jaws of top cutting pliers. I have read the disassembly procedure in accordionrevival and after opening I will play my other accordion nearby to see if there is any sympathetic vibration in the Scandalli. I agree with Debra's earlier comment about the tuning as Bbb is 10 cents high.

Contrary to what others say I do not believe this is just the reed growl. It sounds more "plasticky". What can happen is that the wind from the reed growl causes the valve next to the reed to vibrate. When you let go of the bass button the air flow through the reed stops and the air pressure that keeps the valve next to the reed closed also stops. The reed growl blows sideways in the same frequency as the note and may cause the valve to "flutter" in the same frequency. When this happens I just replace the valve by a different one.

 

[boxplayer4000]

I agree. I don't automatically accept that the 'growl' is inevitable. The bass reed blocks need to sounded out on the work bench where the action of the valves can be observed.
It would be interesting to know if the offending G reed was the lowest in its range. Lowest would suggest heaviest.
The fact that the 'growl' exists on both reeds (pull and push) is annoying and may take us back to looking at sympathetic resonance.