Johann

If i would find a old english concertina i would get it. Would not mind if it is in absolut terrible stae. As long as ti would be affordable to me.

Is really interesting! Looks like the reed bloks are made with acryle as well. And the say it sound perfekt! So this would be an intersting objekt to hear. Johann

Thanks dana, yes this arrengmemt works, the relations of the frequences depend on the reed shape and profile.

Tom way you want to prove that the non harmonic content of musical ton does not count? So actually you agree that higher modes (non harmonics) are present. Usually the are very small depending on the reed type and on the resonance condition. Still, in many cases a lot different exists and this is easy to prove by test you can perform your self. The tests made by Cottingham are not representative at all, the have to be repeated with different reeds, and under different resonance conditions as i did. Then all the the othehr differences that make up a SPECIAL reed instrument are very little too. I if we want something special and or ears are sensitive we hear this little differences! In all this we overlook the transient conditions of a reed, starting and stopping contributes much to how we identify a sound with or human ear but this is more difficult to document because FFT is not mad for this. it looks like we don't want the non harmonic partials, if this is actually the case Then we would have to optimize the reed tong in a way that the reed is profiled in a way that higher modes are dumped as much as possible. The second juice is to tune the higher modes to fit as close as possible the harmonic content of the fundamental. resonance should never damp the fundamental. since higher mode are much higher in frequencies as the fundamental resonance (actually damping) of the wood may well have an effect on the higher mode frequency's. The non harmonic content of a reed is always a part of the sound we all know very well. It is this metallic ringing sound we all know. Reducing the higher mode result therefore in every case in a more pleasant sound. Subjective description again but i think we do not have an alternative to it. Sorry if i cant put it in a better explanation, i wish i would be a native speaker, but even in German language it is not a question to describe it with many pages. To all here building instruments, please use your ears and do more experimenting and trust what you hear. Spectrum analyzes are not of much use to see the difference. Every Instrument has it own personality, no matter how hard we tray to copy th original. some my be close to the original still not exactly the same.

true can the plots be seen? How did you activate the motion of the reed? is some of the relevant writing on the net? Yes i think i and Tom know way and how the natural sera's of overtone get into existence. This is one situation we realize that there are other overtones produced by a reed. Depending on the resonance conditions for the reed some of the possible natural overtones (modes) my be generated by the reed as strong as the fundamental. Usually the resonance conditions are not in away that higher mode are produced as strong to be heard as individual natural harmonic, the are in most cases about more as 10 times smaller as the harmonic overtones present in the acoustic sound, so the can only be noticed as part of the sound color (timbre ). The are so little in amplitude that the usual get lost in the spectrogram. The only can be heard as individual pitch if we already know for what we are looking. (notic also what Mr. Gunter Ziegenhals did write to me: " [...] falsche Profilierung [...] Das hört man deutlich selbst wenn es nicht zum Astoßen führt...." Translation to English: wrong profile [...] this also is heard clearly even the reed is not tughshing the sides of the frame.) To get this natural non harmonic modes strong enough so the can be easily identified within the spectrogram one has to adjust the resonance of the reed chamber so the the fundamental is damped by at the same time the higher mode is not , that also meas that higher mode as fundamental must be quite different and must not meet a harmonic of the fundamental ( this means wrong profile) , so this depends on the reed profile whether it is possible to enforce a higher mode in relation to the fundamental with resonance or not. So by accident it will in most cases NOT be that one will have higher modes present with very strong amplitude to be easily identified on a spectrogram. But, after knowing this now i am convinced that profile and resonance condition change the timbre of the musical sound. Resonance (damping) is not only present by the camber. Also be aware that in some books this is not taken in account because is of less theoretical importance to understand the fundamental operation of a reed. And usually spectrograms do not show the presence of higher modes. The physics of the vibration of the beam modes in other fields of technique are better documented and mathematical models are in use. It is absolutely no new territory of physics. Yes is not as complex as one thinks, still it needs a program to do the job.

Hi Johann, This appears to be an article on a computer procedure for the optimization of reed tongue profiles, and I don't see it's relevance to the quote of mine that you referenced. Is the issue you wish to address on overtones in reed tongue vibration? Does it deal with accordion reeds or organ reeds? Can you summarize this reference, please? Thanks. Best regards, Tom Yes is about calculating program for reed tongues. The content deals with the natural higher mode frequency's es well. Especially the 3rd mode are also calculated and taken into account for finding the optimum of reed profile. I cant give a summery of this three pages at the moment, i had this pages on paper but i borrowed them to a friend who is also interested, i will be with him is a few weeks again. But here is what Gunter Ziegenhals did reply as i forwarded my conclusions about higher mode vibrations of a reed tongue. This was just a few week ago so i am still waiting for a other reply on the subject from his side. It is a very short reply but it defiantly states that the know it all before me. You may contact him yourself and her what he knows. I keep on on the subject but it is to early to say more as i already did. ------ Sehr geehrter Herr Pascher, [...] Mit der Profilierung von Tonzungen hat sich das IfM in den 1980er Jahren befasst. Sie finden auf unserer Internetseite dazu Veröffentlichungshinweise. Suchen Sie nach dem Autor Müller, U. Der Einfluss der höheren Zungenmoden auf den abgestrahlten Schall ist sehr gering, da die Tonzunge ja nicht selbst abstrahlt. Bedenklich wird es, wenn eine falsche Profilierung zu Torsionsmoden führt. Das hört man deutlich selbst wenn es nicht zum Astoßen führt. Mit freundlichen Grüßen Gunter Ziegenhals post@ifm-zwota.de ----

*FEM - ein Rechnerverfahren zur Optimierung von Tonzungenprofilen *Instrumentenbau-Zeitschrift 44 (1990) 9, S. 34, 36, 38 (3 Seiten) read this this was point out to after i had presented may tests about higher mode frquenzys

Hi Tom, I state: "the reed can produce much more as the natural overtone series dependent on the environments." "Plus there is also always some noise within the sound of the reed resulting from the air stream." So it is better to see all not only from a few point of the fundamental and the natural overtones of a reed as we usual do. To see the reed as an distinct noise generator is the absolute opposite to the line above, but if we do this, this can help to understand sound formating better. Tom you came this time quite close to my thinking, remember that if one adds noise as sound source, the wood serves as formating filter and transformer of the source. In my test with noise as sound source the wood bass section of my helicon instruments always had some sort of damping and the resulting envelope of the spectrum curve never had a peak reaching over the amplitude line generated by the loudspeaker without the bass box added. There are some similarity's between a loud speaker system and the bass chamber system of a helicon box. I used the same test system on some bass section of accordions as i used for testing bass reflector boxes. Also remember that amplification on passive loudspeaker systems is possible if horns are in use. It is now some decades back when i experimented with speaker systems and bass horns. Still i also preferred to use passive filters. passive filters are better controllable in respect of phase shifting. Because the wooden parts of instruments cant be made as stiff ans it is possible for load speakers we always deal with some kind of vibration on the wooden parts. You also my reed about loudspeaker how the change the sound if the are made up by cases with walls that vibrate. back to the instruments. Even if your explanation comes a bit closer to the results of or experiments, you also have to think about the grain structure of most ton woods. Wood from the tropical zones is homogeneous wood from zones grown closer to the pols the wood is with year rings. One conclusion form my side could be that tropical woods would have less transforming effects. Frequencies are not altered if the run through the wooden board, if the gain is relative equal as preferred for string instruments the year rings are very constant on old wood grown in past century's. An other thing to think about is that on reed instruments softer wood often is preferred for certain parts of the instruments. For instance, we have one producer of instrument who uses tropical soft wood for the entire reed block except the sole. And everyone can here the difference in sound to a reed block made by spruce with an soft top bar. One accordion builder uses walnut as top for the reed blocks and spruce for the chambers and again the are different. So homogeneous tropical wood like balsa is very effective in damping, without much transforming effect. Result softer but less volume compared to spruce or other ton woods. mahagony is often used to - could it be that this would result in less damping but no transformation as with ton woods? So if wood cames into use that has year rings, could it be that the the grain plays a rule we don't understand up to now? On the other hand if homogeneous wood or ply wood is used (again homogeneous in some way) could it be that the result is easier controllable but not outstanding?

Yes is important, but for accordions it is often thought is a major influence.Or some builders here say it don't count at all, because the use of ply wood for cases is easier in accordion production. But even this builder do a lot on the reed block design and use of wood for the reed block.I've played many accordions in which some have plywood and others aluminum soundboards (as we call the pallet/pad pan item that the reedblocks are secured to) - including Wurlitzer and Hohner PA's and Paolo Soprani and Castagnari BA's. Some of these are models are "twins" where their production had changed from wood to metal - I was hard pressed to discern much of any sound/reponse difference. It seems to me that the method to which the reedbanks are secured to the soundboard has a greater sound/response difference than what material the soundboard was made of. I also note that most reedblocks I've seen are made of softwood bodies and hardwood shoes (or bases - where the exit holes are). Rarely is the top end of the banks or body made of hardwood. I've also seen accordions with plastic reedbanks. One single moulding of plastic per bank. These accordions DID sound somewhat different though very much within the range of "normal" accordions, and the difference could have been due to other factors. -- Rich -- Richard, exactly what i would write about accordion sound board, and reed blocks little change in sound but noticeable. I always did think it is the sound board that could make a big difference, but acutely it is the body, the 4 sides of the case and the reed block, that contributes notable. My preference on the treble side is at the moment to build the sound board as thin as possible or even without, as i did on one box (pallets operate direct on the reed blocks, reed blocks are sealed and screwed to the case frame and removable). And then my main interest is the bass section of helicon boxes. And for the bass side the difference is for me even more noticeable.

Hi John Wild, cant imagin that the reeds did not sound at all. -- hoorible -- differnt -- less volume -- i woul blive.

Dear Theo, free reed + Air column in motion. And undoubtedly most of the sound get radiated in a direct way not via any wood parts. But one has to see the complete system, reed and air colon vibrate more or less in sympathy with the sound formating parts. the rest of this comes very close resonating spots are as far as i could observe do have usual a NEGATIVE "Vally" (Curve in the sound envelope) Still there are certain arias of the sound spectrum that can as well be seen as POSITIVE Peaks but usual this arias of the sound envelope do cover a wider range of the spectrum. If i speak of the sound spectrum i talk about spectrograms i have compared on different boxes without using reeds at all. I compared different helicon bass constructions and wood type used for the bass section with withe sound (noise) generated by a inductive speaker placed instead of the reed. Helicon chambers and reeds are fairly big so this is possible. The difference in sound color is again noticeable be the ear much more as through the visualization in the spectrum. This test arrangements wold be suitable to get "objective" results from a scientist's few point. So one could send a lot of time verifying and documenting different constructions and different material used WITHOUT the reed as sound generator. But i don't provide at the moment with this tests because i am satisfied already and for the end result there is not much to gain because the complete system with reeds counts. Sustain of tone is an other question, and as with all the short answer is not complete. yes simplifying main radiation of the sound via Resonator. Also to much of a simplification, but basically right. If it war only to restrict any sympathized resonance this is not possible and it is more a question of the right damping in the right frequency ranges. To get the instrument sing similar to the the human voice. In the end it douse not matter that the formating works more as damping or amplifier's certain frequency's the end result is similar to String instruments. And with all this the transformation and sustain that happens with spruce and maple ans some other wood types, is not answered with all this. It is also funny that an easy tapping on the wood board by holding the board on one of its vibrating nodes and charging to the resulting tone tells more as all measuring. I prefer to go along with Dana Jonson, he really knows a lot about this.

Dear Tom Tonon, Yes is important, but for accordions it is often thought is a major influence. Or some builders here say it don't count at all, because the use of ply wood for cases is easier in accordion production. But even this builder do a lot on the reed block design and use of wood for the reed block. It comes more on the 3rd place to be taken in account from may few point. Balsa for reed blocks actually don't make a lot of difference, yes true again and i like it. First comes the reed then the dimensions of the chamber and a other construction dimensions than the wood. And my thinking may change a little bit if i do more tests. An other thing is: first comes all must be very stiff and stabil other vice very negative effects of resonance can be noticed. So ply wood is a good average joice with having more a damping effect as an resonance effect. In most cases 4 layers of spruce or beech ply with on layer veneer of any wood is used for the case. So the results are justify able in most cases no matter what wood is used, but better is to keep to the traditional wood. speaking about diatonic accordions. So one has not be vary anxious if one uses something else but in every case the result ma be surprising and sure a bit different. I also can well imagine that concertina construction is more sensitive to the use of wood. Single reed, flat construction with panes ... Rigidness does not mean there is no vibration on this parts. On the rest, i am quite happy with your few point,after now you did say more about it.

Dear Dana Johnson, Thank you for taking your time all you write i could not explain better (even i could us the English language as native speaker) and meet my thinking completely. I may be a bit more like Tom in some way, well because i like to find mathematical expressions to be able to calculate in advance. But at the moment my formulas for calculating reed chambers are far more complex as the formulas Tom did present and the still cant be used in praxis the experience we make is much more important. So i keep on the same way as you do. Yes correct, and Tom states in his paper the t his calculation should not be used for the actual construction the are more of a background of understanding the fundamental things going on. My testing results fit more or less his calculations the fit in a way that his explanations make some sense, but only in mid range pitch it the experimental results and Toms Table get close in higher or low pitch the errors are traumatic and show that the real situation is much more complex. I could post this comparing tables here as well as i have posted them to Tom, still i think the would not be of practical use and difficult to understand. I observed absolutely the same as you describe what happens if the pad hole position relative to the reed position is changed. As this change in ton color (and more or less in pith as well ..)so affect all variations of changes in cavity geometry the sound. for instance if the back wall is variable and its angle is changed the same or similar affects take place. So it is sure not only Volume and the pad opening (Helmholz) (nor the quarter wave resonance) resonance that in fluencies the sound color. If Volume and pad hole is kept the same and the angle of the back wall is mounted variable one can notice this very distinct and even would be possible to present a Spectrogram and a sound sample. I don't have one ready at the moment to post i would need some time to do the tests again because i lost a lot of documents with a Hard disc breakdown. Still quoter wave resonant plus Helmholz resonance are the first that do also effect the ton color. As you state resonance is a NEGATVE peek and should be avoided. It is erroresly often thought that resonance in reed instrument lead to more Volume. (I don't say that there arr some other phenomenons that lead to amplification and more sustain in the sound. More to learn in this respect). So could think that there are many negative peeks resulting from varies resonating spots one is the quarter wave length an other is the Volume resonance (Helmholz) and then we may add different modes from the wood used to build may parts of the instruments. We dont know how strong each of the negative peaks contribute, i can well see the differences in the Spectrogram's in and on different wood used but i am far away to tell the exact frequency's. Still all is better distinctive via or human ear. Than the sound formating of all parts of a box cant format what is not produced by the reed and its air column the first place. So a reed with different dimensions will generate little different sound but it need the surrounding formating factors to support or to damp parts of the possible sound spectrum. So if the reed cant produce some frequencies (dis harmonic overtones, harmonic overtones are always present) the never will appear except via pith change feedback. Or the other way round the formating factors can only damp some of the possible overtones produce able by the reed and its air column. Practical observations back tis very well. Reed sets made by indifferent factory's are suitable for some boxes are not subtable for others and the other way round. For instance especially with cassoto instuments even some high qulity rees cnt be used. This is a practical experience a friend from an well known accordion builder tells me, i cant tell more details the want to keep this to them self. To my person: Being NOT a professional accordion builder, I am a professional Sound - Electronic - Engineer and teacher for microelectronics and Computer Electronics Certified and Trainer for some well known Products, but retired from my regular teaching work. I started as Apprentice for repairing Televisions and wireless in the mid 60is. Worked for one Year in London after i had finished may exams as Tap recording Engineer. Then i made more Exams and i was in charge of a little repairing department for some Years where we also did do a lot of Sound equipment supplying big event with acoustic including big arenas. After more Exams i change completely to micro electronic design and construction and eventually in 1984 i switched to Computer technic and electronic teaching in most cases the practical aspects of this fields. In the past up to about tree years back I covered nearly all fields of modern electronic designs. Actually i would have built a electronic accordion if it would have been possible to get the sound i want, i switched back to acoustic accordions. I stared to experiment with reed instruments about 20 Years ago and the last 6 Years it is getting may main interest and work i am doing. 25 years back I was able to learn from a retired Vienna Accordion builder in 3rd generation some major things like reed making and bellows building, but i never did this work on a regular base just for fun up to the last few years. I am now 55 Years old and retired from my regular teaching job doing occasionally some work in my profession, because it pays the bills beside the money i get for my retirement. So i do have all the time i want now to do more on building diatonic boxes and doing more research.

Hi Tom, yes i can recall what you did write and you know that in most things we think similar. Still I also can make calculation and the can get close to some noticeable effects in realty. But the results are usual not usable in realty and if the are compared with results from measurement the are in most case quit a bit of. You sure must remember that the calculation for cavity in your paper do not completely go along with my testing results. And the are more of theoretical interest as of practical use for construction. The same apply s for calculation on other wood parts of reed instruments. I also made test with different wood cases as well. Spruce makes a big difference to other wood. But i don't go into this, there is so much written material available abut this, is absolutely no new secrete at all. (Not for reed instruments). Still in reality, its more a subjunctive human impression that we get when hearing instruments made by different wood body's. Not the calculations counts, what we like counts. And i cant say it often enough measuring tools are far limited compared to the human ear. Your say tensity and mass is the only thing to take into account for calculation. You are not right in this respect, there are much more physical aspect of a sheet of wood tho be taken in account. grain direction homogeneity of grain cellular structure and much more. Its easy to very fay this take your calculations and different types of wood boards and shapes. And do mode test on them. This has be done before you must know. If you have some technical staff with absolute homogain structure, density and stiffness and physical dimensions my be enough to tell the behaver of this sheet of material. So I believe Dana and my experiences go in the same direction, still for accordions one should not make the mistake to think there is a major influence or difference if different types of wood are used. Please do test on yourself and tell us what was the result are, to present calculations and conclusions without having made tests i don't find this far at all. best regards, Joahnn

Increasing camber cavity volume has an effect on tone color changing toward lower color is may observation. sure this is a very short and uncompleted answer, and i tend to go conform with your explanation. Sure it is a lot more noticeable on Concertinas, one factor is the single reed construction. Sam of my instruments do have registers to switch of some reed sets. And defiantly there is a difference if the one uses reed blocks instead of reed panes. in respect of materials for reed chambers on reed blocks the is not so much notable difference as if the reed are mounted flat on the reed pan. still i tend to see it as you harder materials enforce higher brighter overtone partials. I used balser wood in combination with a hard top for the chamber and the result is a sound that is very much liked on the treble side for me, spruce tree wood for the chamber is usual preferred and gives a bit more on brightness and volume. Still the difference in sound depending on the wood used just for the chamber (top and foot excluded ) on reed blocks on accordions do NOT make a big difference. Also for the top usual a midrange hard to soft wood (Alnusincana) is preferred on Austrian and traditional diatonic boxes. Very much and is the main Factor. Yes go conform, still not the bigest contributing factor. Right, see it the same way. This fits very well with my observation, only the explanation why odd and higher harmonies are more present is because different reed dimensions and shape as you describe tend to produce more higher (odd overtones) higher mode Frequency's as discussed with Tom on the RMS goop. In meantime i had email exchange with the IFM in Zwota Mr. Gunter Ziegenhals and he pointed out a Study the made about 20 years ago where the already came to the same conclusion as i did think have discovered the first time. I hope to get in direct contact to the person (Müller U. ) who did the stud's in the past.The written document is 3 pages long and is tittled: *FEM - ein Rechnerverfahren zur Optimierung von Tonzungenprofilen *Instrumentenbau-Zeitschrift 44 (1990) 9, S. 34, 36, 38 (3 Seiten), Müller U. Interesting, sure this must be more noticeable on Concertinas as on diatonic boxes. Still i think there is a large potentiol of tailoring the sound of reed istruments. And the type of wood used on varies parts of the instrument can surly influence the final acoustic sound heard by the human. The original tests cared out and often quoted to show that the material used for the case of Accordions is of less interest have to be re checked too. Sure the case of the box is not so much contributing as the the reed pan or action board on a concertina or the reed blocks of an accordion still worth to think about. And it well may be that light soft and stable ply wood as used in most cases for accordion boxes is a good alternative to massive traditional spruce wood. Than all is also much a question of taste, i like boxes witch are built with massive spruce tree even i cant her a lot of difference if the box is made by cheaper ply wood. My boxes built with pear wood sound also quite good to me but the are a little bit different especially for the basses. Is hard to tell how much lately comes from the wood used for the case.Still i tend to think there is a formating influence moved a bit up in the spectrum of sound if harder wood types are used. Spectrum analysis of all my boxes show differences but it is not possible to tell from where the differences come by looking on the spectrum diagrams. It still is much more guessing as knowing from my few point. Johann

I am in some experiments on diatonic helicon boxes. Richard and Ton and may be some other do know me because we exchanged mails before. First my intention was wood makes the biggest difference in sound quality and sound formation. All the boxes i built are different in many aspects, so the resulting sound is quite different if one compares the boxes. Then i do have a few old boxes and the sound is different again. The last experiment was rebuilding one old box with the same dimensions as an old two row box. The sound of the old two row box is liked by me very much. After i had taken all wooden parts apart i cleaned all and actually rebuilt the complete 3 row box. First the reeds are the same type of this two boxes. Old German DIX Zinc reeds in good condition. One box is with 2 rows the other is with 3 rows. Dimensions are equal because the same Factory made this boxes originally. No difference in construction except one has 2 rows and the other 3 rows. Red blocks are absolute equal in dimensions and the type of wood used. The only difference is in the type of wood used for the complete box. The 2 row box uses play wood on the complete case and sound board. The rebuilt 3 row box is completely made from massive spruce tree with nut veneer on top. Sound board is also a massive board of the same thickness as on the 2 row box. But i don't know the name of the wood type for sure. The tuning of the boxes is done in the same way. I never rebuilt the bellows until jet, i just stitch the bellows from one box to the other. Workman ship is quite poor especially on the 3 row Instrument. Not much car ware taken to make it look nice inside. Before rebuilding the 3 row box the box sounded very poor. Still it had a lot of signs of hard usage so it must have bin a good box other vice it wold not have been in use so much. Many gluing connection just lost there secure connections over time. Now both boxes sound very similar sure not completely equal. The 3 row box seems have a little more sustain in sound as the 2 row box. My conclusion: Reeds make the biggest difference but have to be lately seen in combination with the complete box. Bad design cant be fixed with better reeds. It is some sort of marriage reeds and design. The absolute main factors. Material too but much less of influence as i did think for years. Also some privies experiences do prove the same to me. Before this rebuilding job i made an other experiment with an old 3 row box. This 3 row box is even older and i had rebuilt or fixed the mechanic and the bellows years ago. Still i was never satisfied with the sound so it was nice looking but not in use much. Replacing the reeds changed the treble side dramatically but not to the better at all. Replacing the soundboard on the treble side made a change in talk reaction on the higher notes. The thickness of the sound board was 8 mm in the fist place now it is 0,5 mm and the material was first massive nut wood. Now it is glass fiber. Sound color is not noticeable change except on the upper higher notes. Still the treble side is now quite usable, to change it to the better i will rebuild the reed blocks with different dimensions as soon as i find time. But the bass was very dull without higher overtones. So i did a major rebuild on the bass side as well. I only kept the outside frame. All inside on the buss side was rebuilt with new spruce tree and little other wood in the same way and with the same dimensions as before. The same reeds ware used again. Result: Buss change somewhat to the better. Now there is more sustain and a lot more of higher overtones are present. But the the main character in bass sound remained as it was before. The lower formatters of the sound did stay as the ware with the old wood. So it looks like braking in and aging removes higher overtones, But changes nothing on the main sound formation given by construction and dimensions. And it looks a new box always will sound different and brighter as an old one. Some people don't like the sustaining ending sound of the buss side of modern helicon boxes shortly after a valve is closed. Traditional construction on the bass side reduce this but the main difference makes the aging of a box. Dimensions changes on the chamber has the biggest effect on sound formation in the frequency rang comparable to or human voice. Box size seems to influence the sound formation in the very low regions around 100 Hz but this is to prove a bit better. I think also that the relation of the case length to width could be of interest to. So if one copy's a box exactly with its dimensions exactly as the original and he uses nearly equal reeds and the same tuning the possibility is very high to end up with a sound very similar but sure with a bit more of higher overtones as the older box. Boxes from a series of the same production sound usual nearly the same because the use absolute the same dimensions and in most cases the same material. Still not one box is exact the same as the other, so from where come the little differences? This is hard to tell because very little differences remain, the tuning of the reeds is never absolute the same to. I was tolled at Müller the biggest Austrian production for diatonic boxes: The person making the final check on a box usual can tell who did the major work on the box without know who was it. Each box has to some extant sings of the builder in respect of how the keyboard action works and how the sound is. There would be more on comparing sound formations from my side. More comparing of different box sizes. I made test with empty boxes made of different wood. Most of my tests are in respect of bass chambers (cavity), and some are on treble chambers. On the mounting of the reed. And naturally on the reed it self. All in all, it is very hard to give exact direction what has to change to change the sound in a other direction. All is very complex and nearly impossible to but it on a scientific level. best regards, Johann