09:21 AM Soldier Dick said:
"Steve Dickinson, a noted concertina maker makes it very clear in the clip i provided.... he explains exactly why there is a difference in sound, between accordion reeds and concertina reeds and between the two different constructions of concertina".

Hello guys, despite probably annoying some of you this referrence can not stand un-opposed. With all due respect for Steve Dickinson and his unquestioned merits as a maker I am sorry to say that his description in the video really is not quite adequate. With excuses for minor swenglish misinterpretations on my behalf this is what he says:

"…concertinas have a different sound from accordions…what makes that uniqueness?…the sound of the actual reed
is modified within the instrument...the reed itself vibrates within an inclosed chamber…that can be approximated to
a simple harmonic motion by the reed and every space has got a resonance frequency..the (chamber) space is arranged so that its frequency is comparable with that of the reed...the two combine and amplify the sound ...this gives very pure sound whithout any overtones...you don't get this in a melodeon or an accordion because the reed in those operates in a free space...they don't have this chambered arrangement"

There are a some factual misunderstandings here and my guess is that he uncritically has adopted traditional hearsay. He is in good company however in such case...Neil Wayne in "The Wheatstone English concertina" in Galpin soc.March 1991 page 139:said:

"It was Charles Wheatstone's research on the acoustical linkage of tuned pipes and chambers with metal free reeds
in 1828 and 1830 that led to the introduction of tuned reed chambers into his firm's concertinas and as early as 1838
most of his concertinas had at least three or four of their smallest reed chambers fitted with a cork cross piece to
adjust the volume of the chamber and to tune it to the resonant frequency of the reed within the chamber…."

I have heard/read similar reports from others too so it is difficult to explore from where the ideas originate.

First in theory:
The matter of resonance in physics is a highly mathematical issue.The resonance frequencies in the lower octave chambers in a
treble concertina may be around 5000Hz if the chamber is around 50mm while the correspoonding reed frequency is around 200 Hz. The consecutive measures of chambers do not correlate to the sequence of reed frequencies either. You simply can not get the needed size of instrument to execute the assumed "frequency comparable with that of the reed" or "tuned reed chambers" .Even if you calculate with higher resoncance frequences it is impossible t achieve any consequent tuning of the chambers.

Secondly in practise:
The matters of resonance in accordions have been scientifically investigated and documented for example at the old "Institut für Musikinstrumentenbau in Zwota". I did some tonespectrometric studies myself in the 1980s with concertinas and did not manage to reveal any significant resonance phenomena at all, neither from the chambers nor the box..
The maybe most obvious proof that there is no amplification from the chamber or other coloring of the tone from the chamber acting on the individual reed comes from the Anglo as there is no major difference in sound between push and pull notes acting in the same chamber while the note frequencies may differ considerably.
The presence of the reed chambers IS the same with all squeezeboxes and the true technical function is to separate the air flow between the reeds and to offer efficient pressure and air flow conditions ! NO acoustical intention with them at all BUT they do modify the sound more or less still - seemingly primarily by absorption of higher (overtone) frequences.
It is of course obvious however that most "concertina reeds" sound differently from "accordion reeds". The influence from box factors may be considerable too. For instance does the exactly same reed produce a different sound in a common treble vs in a big baritone or baritone-treble.