Converting double action to single action.

[Bassconcertina.net]

Hello, for double action bass concertinas do you think it would be possible to convert double action to single action? I have some ideas but I’ll share them once I get some of your ideas. Thanks!

[alex_holden]

You mean remove half of the reeds, block the wind slots of the missing reeds, remove the valves from the remaining reeds, and add some air intake flap valves? Yes, but I'm not sure why you would do so. It would reduce the weight but not the overall size of the instrument.

[Bassconcertina.net]

6 hours ago, alex_holden said:

You mean remove half of the reeds, block the wind slots of the missing reeds, remove the valves from the remaining reeds, and add some air intake flap valves? Yes, but I'm not sure why you would do so. It would reduce the weight but not the overall size of the instrument.

Thanks! I want to do it because a double action bass can be slow to speak and quiet compared to single action. I don’t have one yet but I’m curious.

[alex_holden]

3 hours ago, Bassconcertina.net said:

Thanks! I want to do it because a double action bass can be slow to speak and quiet compared to single action. I don’t have one yet but I’m curious.

 

I doubt removing half the reeds would help much in that respect. The only benefit I can think of is that you can do away with the valves, which might make them slightly louder and faster.

 

I think some of the reasons a single action bass that is designed that way from scratch may be faster are:

The reed chambers can be narrower, which gives you more space on the reed pans for longer reeds in longer chambers.

Some of them have double-decker pans, which also helps to fit in longer chambers.

If the reed chambers take up less area you can potentially make an instrument with a smaller cross sectional area (double decker pans help with this too), which increases the pressure you can generate in the bellows for a given amount of physical effort.

[Bassconcertina.net]

35 minutes ago, alex_holden said:

 

I doubt removing half the reeds would help much in that respect. The only benefit I can think of is that you can do away with the valves, which might make them slightly louder and faster.

 

I think some of the reasons a single action bass that is designed that way from scratch may be faster are:

The reed chambers can be narrower, which gives you more space on the reed pans for longer reeds in longer chambers.

Some of them have double-decker pans, which also helps to fit in longer chambers.

If the reed chambers take up less area you can potentially make an instrument with a smaller cross sectional area (double decker pans help with this too), which increases the pressure you can generate in the bellows for a given amount of physical effort.

By do away you mean get rid of right? Or replace, add helper springs? I suspect that if the valves are just removed the reeds will be really slowed and breathy. Do you think plastic accordion valves, helper springs or new leather accordion valves would work on a a double action bass concertina? Thanks!

[alex_holden]

I mean you can remove the valves if you convert to single action. They are there to prevent the push reeds opening and wasting air when you are pulling and vice versa. If you only have reeds for the push direction it doesn't matter if they leak when you pull to refill the bellows. You would of course need to block the wind slots where you removed the pull reeds.

[Łukasz Martynowicz]

4 hours ago, Bassconcertina.net said:

Thanks! I want to do it because a double action bass can be slow to speak and quiet compared to single action. I don’t have one yet but I’m curious.

 

As Alex wrote, the main reason those are slow to speak and quiet is probably that chambers are too short. You need a lot of length between the tip of the tongue and the padhole to improve that, like 200-250% of the tongue length. Setting of the reed and stiffness of the valve may also play a role, but to lesser extent. Increasing stiffness of the valve above what ensures airtightness only increases the pressure offset required to operate the reed - the attack of the reed may be steeper, but it will operate only if you push bellows harder. Plastic valves do not really work with bass reeds, because the larger/stiffer plastic valve is, the more noisy it is.
 

[d.elliott]

I now have a single action bass, and a single action baritone. I sold my double action baritone to get the SA version. The lag in closing one valve to open another on a small reed instrument instrument is acceptable, but on a big reed instrument not only are the areas of leather so much greater, if add the effect of the heavier leather plus again the size & weight of the reed and it all becomes bit like a plumb pudding to play. The longer and heavier valves tend to stand off the reed pan more, especially the non-chamber side of the reed pan. Remove the valves and all that (except the reed size) goes away. My Wheatstone SA baritone is comparable in responsiveness with my either of my. Wheatstone trebles.  

 

I would never revert back to a DA baritone, having aid all that you can make terrific improvements in playability and responsivness on DA big reed instruments by judicious choices of valve leathers combined with valve springs. it can be a bit of an art form but so well worth the effort. I would always advise optimising what you have before spending lots of dosh on replacement. 

[Bassconcertina.net]

4 hours ago, d.elliott said:

I now have a single action bass, and a single action baritone. I sold my double action baritone to get the SA version. The lag in closing one valve to open another on a small reed instrument instrument is acceptable, but on a big reed instrument not only are the areas of leather so much greater, if add the effect of the heavier leather plus again the size & weight of the reed and it all becomes bit like a plumb pudding to play. The longer and heavier valves tend to stand off the reed pan more, especially the non-chamber side of the reed pan. Remove the valves and all that (except the reed size) goes away. My Wheatstone SA baritone is comparable in responsiveness with my either of my. Wheatstone trebles.  

 

I would never revert back to a DA baritone, having aid all that you can make terrific improvements in playability and responsivness on DA big reed instruments by judicious choices of valve leathers combined with valve springs. it can be a bit of an art form but so well worth the effort. I would always advise optimising what you have before spending lots of dosh on replacement. 

Thanks a lot! Do you think a conversion from DA to SA would work?

[SteveS]

On 1/21/2023 at 10:03 PM, Bassconcertina.net said:

Hello, for double action bass concertinas do you think it would be possible to convert double action to single action? I have some ideas but I’ll share them once I get some of your ideas. Thanks!

Whatever course of action you take in converting a DA to SA bass, make sure your changes are reversible, so that it can be reinstated to DA if required sometime in the future.  
And reeds you take out store them in a safe place.

Edited January 23 by SteveS

[Bassconcertina.net]

1 minute ago, SteveS said:

Whatever course of action you take in converting a DA to SA bass, make sure your changes are reversible.  

Thanks and Yes, I definitely am going to keep it reversible, my plan is about the same as Alex Holden's. I might not have to now hearing some of the other things I could do. But just in case.

[alex_holden]

2 minutes ago, Bassconcertina.net said:

Thanks and Yes, I definitely am going to keep it reversible, my plan is about the same as Alex Holden's. I might not have to now hearing some of the other things I could do. But just in case.

 

To be clear, I only said it was possible. Personally I wouldn't do it.

[d.elliott]

If you want to try this out then use a couple of the low notes valves on each side in place and working, these will act as internal 'gulper' valves. all you need to do is remove the chamber side reeds and tape over their reed vents. I don't think you will gain much in volume, but definitely in weight loss (most of use want that- certainly according to my wife). The main benefit will be responsivness in play. My own bass has a single internal gulper port & valve about 30mm in dia.

 

Picking up on Alex last comment, for me this would be an experiment, or at most a step on the path towards getting a proper SA instrument with it's much bigger reeds. Any such mods would need to be reversible. Please also consider that many of the DA Basses have relatively shorter reeds with weighted tips, all of which have an impact on responsivness.

[Bassconcertina.net]

3 hours ago, d.elliott said:

If you want to try this out then use a couple of the low notes valves on each side in place and working, these will act as internal 'gulper' valves. all you need to do is remove the chamber side reeds and tape over their reed vents. I don't think you will gain much in volume, but definitely in weight loss (most of use want that- certainly according to my wife). The main benefit will be responsivness in play. My own bass has a single internal gulper port & valve about 30mm in dia.

 

Picking up on Alex last comment, for me this would be an experiment, or at most a step on the path towards getting a proper SA instrument with it's much bigger reeds. Any such mods would need to be reversible. Please also consider that many of the DA Basses have relatively shorter reeds with weighted tips, all of which have an impact on responsivness.

Thanks! do you think the chamber side valve would need to be removed too?

[d.elliott]

Those valves would be redundant, and may cause some air flow resistance, but minimal (assuming they are good valves)