alex_holden

I think it's a Jeffries duet. See Fig. 26 in this article: https://www.concertinajournal.org/articles/charles-jeffries-and-his-sons/

Here's Ralph Jordan playing Bach's Gavotte in G Minor on a 58 button Wheatstone Maccann duet, courtesy of Alan Day and Wes William's Duet Recordings page: http://www.concertinas.org.uk/DuetAudio/RJ01.mp3

Or this on a Lachenal 48 button treble English played by @Wolf Molkentin:

How about a harmonica? Similar free-reed type sound, and you can buy a decent one for a lot less than a good concertina.

Do you mean, if you put an F3 reed in a particular chamber it sounds poor, but if you swap an E3 or F#3 reed into the same chamber without changing anything else it sounds fine? I don't know. I have tried adding chamois gasket material to the back wall of an inner chamber (on the theory that maybe the bellows frame lining is absorbing some harsh harmonics), and I couldn't hear any difference. Also @Dana Johnson's reed pans seem to be routed from a single block and have solid back walls, even on the outer chambers. http://www.kensingtonconcertinas.com/photo-album/5-inch-reed-pans.html My current best guess is that it has something to do with how the sound resonates inside the action box. I tried fitting a small dummy wall inside the action box next to an inner chamber pad, with again no noticeable difference.

I don't have a solution, but I have noticed on traditional-style instruments that you get similar tonal differences between chambers that have the pad close to an outer wall and ones that are closer to the centre of the pan (what I call "inner chambers"). I've not yet figured out why it happens or how to prevent it, other than making the instrument bigger and moving the chambers to the outside of the pan. The effect seems stronger when the affected reeds are lower in pitch.

I find that modern iPhones have a pretty decent video camera, but you can tell if the sound was recorded on the built in mic. Recently I've invested in this audio setup: 2 fairly good small diaphragm condenser mics (sE8, but there are cheaper options). 2 mic stands 2 XLR cables A Steinberg UR22 MkII USB audio interface An Apple Lightning to USB camera adapter (the bigger one with two connectors on it) A two port USB charger A USB A to micro USB B charger cable A USB A to Lightning charger cable A pair of headphones Here's how I set it up: Put the mics up on the stands so they are about 30 cm apart, facing the player from a distance of about 1m (you'll probably want to experiment with placement later but that should be an OK starting point). Enable phantom power on the audio interface. Make sure Input 2 Hi-Z is switched off. Plug the mics and headphones into the audio interface. Connect power to the micro USB socket on the interface and set the power source switch to that input (this step is important - it won't work if you try to power it directly from the Apple camera adapter). Plug the camera adapter into your iPhone, and the USB A-B cable from the camera adapter to the audio interface. Optionally plug a lightning charger cable into the camera interface - this will avoid running the phone battery down while you're filming. Twiddle the Input gain knobs to about 50%, the Mix knob all the way to Input, the Headphones knob fairly high, and you can ignore the Output knob. You can now try playing the instrument while listening to the headphones, watching the "Peak" LEDs, and adjusting the gain knobs. You want to be able to clearly hear yourself in the headphones, without hearing crackly clipping noises or seeing the Peak LEDs flashing when you play at your highest volume. When the gain seems OK you can take the headphones off, and use the phone's camera app to make a video recording. If everything is working correctly it will capture the sound from the external mics instead of the internal one. To listen the playback through the headphones, you'll need to twiddle the Mix knob over to the DAW side (that means you're hearing the output of the player on the iPhone rather than the live input from the mics). Here's a recording I made of @Little John a while ago using my iPhone's built in mic: And here's a recent recording with the audio coming from my new setup instead. I did boost the gain in post, but I probably could have avoided that if I'd got the input gain knobs adjusted better in advance (I was being a bit paranoid about clipping).

Are we talking about two different phenomena? What I think of as "choking" is when the pressure quickly goes from nothing to 'very high', the reed gets immediately pulled part way into the vent opening, blocking the airflow and preventing the oscillation cycle from starting up. If you bend the reed up slightly so there is a larger gap at rest, you need to use higher pressure to make the reed choke (but the reed doesn't start as easily at low pressure). This effect also happens on my tuning bellows, which doesn't have a chamber between the reed holder and the bellows cavity. It sounds like you are describing the situation where a particular chamber just doesn't work for a particular pitch. The reed mysteriously won't sound, or it's very weak. You change the size of the chamber and it starts working again. I've occasionally seen that happen while experimenting, though luckily not in an instrument I built.

Yes, that's right. Also a stiffer valve lowers the pitch in the instrument. I don't really understand why that is, but I've observed it many times. Sometimes very high reeds have no valves, and those can be fairly close to the same pitch in or out of the box.

You did well. I still struggle to make my pleats inconspicuous. Some leathers are worse than others for this.

My current tuning bench doesn't have reed chambers like Dana's; the reed holder simply sits over a set of bellows. The reeds definitely don't perform as well in the open air as they do in the instrument, especially at the low end, below perhaps G3. Once you get down to G2 or so they won't even start in the open air - you have to pluck them, then they sound extremely quietly. If you somehow built a real instrument with no chambers I think it would perform very poorly. I'm planning to build a new tuning bench soon and intend to incorporate several chambers in a range of sizes. It depends on how well they are made and how you set them up. If I'm setting up an instrument for a gentle player, I'm typically aiming for them to start at less than 25 Pa (0.1 inches of water) on the tuning bench, though for technical reasons I find that isn't achievable at very high pitches and I have to settle for perhaps 50 Pa. Once in the instrument, the valves start to make a difference to the minimum pressure that is practically achievable because the reed you're currently trying to sound may not start until there is enough air leaking through the opposite reed to pull its valve closed. With good valves that close very easily, you can barely feel any force on the bellows before the reeds start to sound. If I'm setting up an instrument for a loud player, it's necessary to set the reeds higher or they will choke too easily, and that has the side effect of raising the minimum playing pressure - maybe to 100 Pa or more.

I concur with what Łukasz and Dana have already said. The other thing is the effect of scaling - a shorter than usual bass reed (i.e. more heavily weighted at the tip and/or very thin near the clamp to pull it down to the required pitch) will bend more easily than a longer one. This was often done to squeeze in more buttons or a lower range without increasing the overall size of the box. Some vintage instruments are quite tricky to tune because you have to aim for the bendy bass reeds coming into tune with the rest of the instrument at the player's normal volume level (which varies with playing style). If you then play at a significantly lower pressure the bass reeds go sharper than the treble, and if you play at a higher pressure the bass reeds go flatter than the treble.

Interesting pictures; the pierced sides are quite unusual and I don't think I've seen that on a Lachenal before.

I would quibble slightly with the statement that the concertina is "a branch of the accordion family". It's more accurate to say that they are cousins in the bellows driven free reed aerophone family, with some superficial similarities and a great many differences in the construction details.

Also: (I'm currently tuning another Crane duet to 1/5,MT)