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Edward Powell
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AIR/BODY RESONANCE TONES
WHAT MAKES THE AIRSPACE/BODY RESONANCE TONE?
...you know, that strong tone you get when you sing into the soundhole? Kind of a WHOOF that shakes the whole instrument when you 'hit' it.
What causes it?
-volume of air?
-resonance of back material?
-general resonance of all materials combined?
-LENGTH of the air space?
Here is a collection of my instruments which I checked for air resonance tones:
From left to right, I will give the AIR/BODY RESONANCE TONES, that I found for each- from left to right each instrument has a progressively LOWER
air/body peak tone.
1 (far left)- ragmakamtar #6 - F# (4th fret on the D string of a guitar) is the air peak tone. strange because the actual air space is pretty big
with a body depth of about 16cm. However, the body is not SO long (not so short either), but the instrument all in all is under tremendous tension
from 31 strings. Also having the 3 necks might be stifling resonance? The back is made of papier mache and a bit of bondo and is NOT very resonant. It
also has very big neck and back blocks and 4 suspended braces inside. The air tone is F# but is is not very powerful.
2 - Arabic oud- C# (but with strings OFF the air tone goes DOWN TO B!!!!
3 - extremely cheap total crap guitar (extremely heavy wood and bracing!) - B (no strings). Is this not STRANGE? The body is SOOOOOOO thick that it
can not be resonating, but still it has an air tone the same as the oud! The body is much more shallow than the oud's but the air space is a bit
LONGER (and MORE of the air space has that long length - THIS IS THE ONLY THING I CAN SEE THAT WOULD EXPLAIN THIS SURPRISINGLY LOW AIR TONE ON SUCH AN
UNRESONANT INSTRUMENT!). ---but it has a small sound hole and I heard that this creates more bass.
4 - "the insect" (original instrument with body a bit like a "sape". Air tone = A (with strings on!)... so this is a very very low air resonance for
a very very thin and shallow instrument - BUT THE AIR SPACE HAS A LOT OF LENGTH!
5 - "the sartar" (another original instrument) G (no strings) so this has an air tone very similar to "the insect" even though it has MUCH more air
volume --- BUT THE LENGTH IS VERY SIMILAR!
6 - "gambri" - G... similar air volume and length as the "sartar + insect" both
7- "BIG GAMBRI" (afrobass) low D (like drop D on guitar E string). This has the longest airspace.
- - -
I would think that taking the strings OFF the oud made it's AIR TONE go down by a whole tone, would prove that the general resonance of the body (with
strings off the body is undo no tension and is therefore suddenly much more resonant) contributes greatly to the air-tone.
BUT then how can we explain such a deep low air resonance with this thick plywood guitar which has the resonance of a concrete slab???
I'm confused.
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fernandraynaud
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"I'm confused."
Of course. You have too many instruments, and in addition you are trying to make ouds grow sarod necks.
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Edward Powell
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No, I am trying to make sarods protrude oud bellies!  )
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Manil
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Hey you play guembri too, I have one a small one called Aouicha, I like this instrument a lot, to repond to your question, I have no clue
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ALAMI
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Hi Ed :
Quick and incomplete answer: check Helmholtz resonance principle.
Some infos are also somewhere right on these forums.
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rojaros
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Hi, it's Helmholtz resonance.
But: the body and the top of course act as a filter, and depending on many interdependent factors they
1. make the resonance sharper or wider (Q-factor)
2. By possibly having some resonances near to the Helmholtz frequency or its multiples the can add some sum or difference tones that also could be
audible or influence the resulting pitch of the resonance. It's a highly coupled system of many parts that are capapble of vibrations!
Best wishes
Robert
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Edward Powell
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Helmholtz yes... but how does this explain that the oud's resonance dropped one whole tone simply by taking the strings off? Would not THIS
indicate that there is a strong WOOD resonance here, because removing the tension on the body will surely increase resonance which will make the peak
tone drop!? So for me this proves it is not ONLY an air resonance.
Having said this - then how can it be explained that the CHEAP GUITAR and the SMALL GAMBRI have such low air resonance - since both do not have
expremely large air spaces, and BOTH HAVE EXTREMELY STIFF, THICK, NON-RESONANT BODIES..... this observation tends to support the theory that the
LENGTH of th air space is what makes the most difference.
And lastly, how can it be explained that the ragmakamtar which has a very large AIR VOLUME, actually has a pretty high (F#) air resonance???? One
theory I might offer is this--- maybe the F# I am picking up on the ragmakamtar is actually an F# lower than I am registering (which makes it close
to the SMALL GAMBRI). And maybe the fact the RAGMAKAMTAR is so big, and has such an unresponsive back - maybe this is causing a general
unresponsiveness in the instrument - - - - someone on the luthiers' forum suggested that a very large instrument can lose it's responsiveness (like
trying to blow a tune on a COKE BOTTLE when the opening would be 3X larger.
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rojaros
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This all points to my 2d point - there are many couplings of different modes of vibrations, and certainly there are some standing wave modes that are
interacting with the 'helmholtz' mode (which Helmholtz studied on spherical cavities with stiff walls and relatively small openings, so that there
were not so many coupled modes).
As for the tension release of the top: certainly the fundamental top mode frequency goesn down when the strings are loose, because the the top is then
working with smaller Young modulus.
Maybe the released top of your oud has an fundamental eigenfrequency that is lower than the air resonance.
best wishes
Robert
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Edward Powell
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Hi Robert
I am not sure I completely understand your last point unfortunately.
But I think you nailed it when you say that the oud's air resonance is a combination. I feel that the back and the airspace are peaking at the same
pitch. This is also true of good guitars. Therefore we get a resonance that really helps the guitar/oud's tone.
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rojaros
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Hi Edward,
I'm also only guessing from my general physical knowledge. Beeing around with accoustic instruments for most part of my life I have learned to know
that we don't know much how they really work - one can be sure they are very complex in their mutual interactions and interdependencies. And the
better an instrument is, the more complex it is.
I have had many many discussions on these issues with my good friend and accomplished guitar maker Sebastian Stenzel, and, though I have a long
standing acquaitance with classical guitars, I'm sometimes surprized by his foundings, which I at first glance find counterintuitive, but which work
obviously very well, as his masterly made guitars prove aboundantly.
As to the last point: Wood certainly has a variable elasticity coefficient; which means, when it is relaxed, it's lower, and when you bend it (which
mean, if you apply tension), it becomes stiffer, the closer you come to the point where it would just break. That's also why every top of a guitar (or
oud for that matter) has a certain optimum working point, and if you put on strings of a too low or a too high tension, it's pushed outside of the
optimum working.
Now, when you relax all strings, the tension on the top gets much lower, so it's having a much softer elasticity, which means that the fundamental top
mode frequency is also much lower. If it's energy is transferred more efficiently than that of the air resonance, then this is what you hear, because
there is the masking effect of the softer source by the louder source ... That's the effect I'd suspect - but of course I might be wrong.
best wishes
Robert
PS See Sebastian Stenzel with some very interesting articles on different aspects of guitar making for download
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rojaros
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PS For his first Oud see also Stenzel Oud
best wishes
Robert
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Edward Powell
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...yes, less tension on wood means more flexibility which means lower resonance.
So if my oud's "air" resonance goes down when the string tension if off, this means that we are NOT so much hearing an "air" resonance, but rather a
wood resonance that is being affected by the string tension. I probably means the soundboard - - - BUT the string tension is putting stress on the
entire body including the back (and even the necks). So still theoretically it might be a back resonance also we are hearing. (?)
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rojaros
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I don't think there is much back resonance in oud anyway. Being bend it's quite a stif structure, and it's modes, I suppose, are much higher in
frequency.
You could find out about that when the oud is without strings, by tapping softly against top, body and neck and see what you get. Maybe you find the
spot where you can triger the same note...
Best wishes
Robert
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Aymara
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I'm not an expert, but to my understanding there are mainly 3 factors, that influence the sound of acoustic stringed instruments besides the string
choice:
1. the soundboard (incl. bracing and soundhole size and placement)
2. the body (air capacity and shape)
3. the neck
And we also know, that the choice of woods is important. If you have two ouds for example, that have the same body design, a rosewood bowl would have
a deeper bass than walnut.
So I guess, that besides Robert's explanations about soundboards ... we shouldn't forget the bracings by the way ... every of the three main parts
have their own eigenfrequency, which in sum produce the resonance frequency of the whole instrument.
Or am I wrong?
Regarding the Ragmakamtar ... don't overlook, that though it's body has a high air volume, the body is relatively flat, which in my opinion is the
main reason for it's high resonance frequency. Do a bit of research about acoustic bass guitars and you'll find out, that you need a deep body to
achieve a deep bass ... do you remember this mexican bass guitars? 
PS: The average acoustic bass guitar lacks deep frequencies and sounds only a bit deeper that a western guitar, because it responds mainly in the
lower mid range. There's only one acoustic bass guitar on the market, that is different: the Stoll, which sounds nearly like a contrabass, though less loud ... look HERE.
Greetings from Germany
Chris
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Edward Powell
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Actually, the ragmakamtar version I am talking about (version6) has a back depth of 18cm which is pretty deep I would say. I made it this way to "get"
that deep air resonance, but it didn't work so well, although it was an improvement over all the previous ragmakamtars.
I have a feeling that what is more important than the width and depth of the air space is the LENGTH. I have a hunch that increasing the length of the
airspace will give more bass the quickest.
Back to the ragmakamtar; I am not sure where the current problem is --- but I have a few guesses:
- back is made from heavy papier mache and not at all resonant
- it has 3 necks which add a lot of extra weight - further dampening resonance
- air space is pretty wide and thick but not long - not a focused shape like a bottle or a pipe, perhaps this air shape is more difficult to "excite"
being big and round rather than long and tight?
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Edward Powell
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Quote: Originally posted by rojaros  | I don't think there is much back resonance in oud anyway. Being bend it's quite a stif structure, and it's modes, I suppose, are much higher in
frequency.
You could find out about that when the oud is without strings, by tapping softly against top, body and neck and see what you get. Maybe you find the
spot where you can triger the same note...
Best wishes
Robert |
I made the ragmakamtar version 6 back from papier mache which is thick, heavy and really non-resonant - because of the theory that the back does not
influence the sound. But the result is that I have not much and not very deep air resonance, even though the soundboard is very large and very lightly
braced.
Anyhow, at the moment I am building a new ragmakamtar with a very light and resonant thiin wood back, so it will be interesting to hear the
difference.
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rojaros
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Well, by stating that there is not much back resonance in oud I didn't mean at all that it doesn't play an important rôle in forming the sonic
characteristic of the oud; quite on the contrary: the body and the neck and the peg box all function as frequency selective filters and they give
coulour to the sound, also they certainly influence the attack and the sustain of the oud.
But these things do not concern the deepest frequencies; I don't think the bowl is radiating any significant amount of energy by itself thereby
contributing to te level of fundamental frequency of the oud. (What I feel with my stomac are certain resonances quite a way up over the basses).
As I cannot become tired of emphasizing: any accoustical instrument, especially anything made of different woods and with a quite complex geometry is
an intricate system of coupled vibrations and any attempt to isolate one factor over the others has only a limited value.
Interestingly enough an experienced luthier kind of intuits (I could say as well: knows on a pre-intellectual level) what has to be done in order to
achieve a certain overall character of the instrument.
As Sebastian Stenzel stated immediately after I played his first oud for the first time: "The sound doesn't come as a surprise to me; it is exactly as
I have envisioned and intended it, and the extent to which this is the case, that is the surprize!" (maybe not the exact wording).
And I knew intuitively he is fully capable of doing that; otherwise I would't have ordered an oud from a luthier who yet hasn't built any.
Today, after three days of intensive playing, the oud already is in a shape I wouldn't even dream of it's possible!
Why I'm writing this? Because it points to the limitations of our explanations of the accoustical behaviour of complex instruments - without a lot of
experience we allways will be doing more or less educated guess work ...
best wishes
Robert
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Edward Powell
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Hi Robert - thanks again for your amazing insight.
Here is my current thinking:
In my attempt to solve the "ragmakamtar riddle"... and a lot of brainstorming later, I can say that my current thinking can be summarized as
follows:
- the back of an oud is not so much responsible for the bass range. However a "good" back will "help" the instrument's volume, sustain, and attack
since it is resonant and encourages vibrational flows. Therefore the ragmakamtar's non-resonant papier mache back is probably one reason for the
instrument's lack of volume and attack.
- I feel now that the air-peak tone (what we get when we sing into the hole), is NOT coming from the back, and in fact also NOT coming from the
Helmholtz, but it is mostly coming from the soundboard. Perhaps a coupling of the soundboard and the air resonance - but I feel it is mostly from the
soundboard --- otherwise why would it be that when I took off the string tension on my oud, the air-peak tone dropped a whole tone? Furthermore,
obviously the soundboard has a lower resonance than the back...
- I had previously thought that the ragmakamtar's air tone was F#... the F# (4th fret of D string on a guitar) because this the only peak tone I could
find, and it was pretty weak (which I attributed to the papier mache back). BUT(!) and further thinking, observation, and analysis I think I have
realised a very very important mistake in my assumptions... First is following with the idea that the air-peak tone is primarily coming from the
soundboard - - and second is that when I play the lower F# on my ragmakamtar (like 2nd fret of E string on guitar), then this low F# is actually very
loud and fat!!! The F# an octave above is NOT very punchy at all - certainly not a full fleged "peak tone" --- again I was blaming this on the paper
back. . . but I have finally opened my eyes to the fact that what I have done with the design of ragmakamtar version 6 is to OVER COMPENSATE and in
fact make the body, soundboard so large, and the bracing so light - that the result is a general soundboard resonance tone MUCH lower than an oud's!
I think I just almost didnt want to SEE this because I was so sure that this would not even be possible - but yes, I am pretty sure that in my long
struggle to get a deeper oud sound I finally overdid it and put the resonance SO LOW that it is out of range, and therefore is missed in the
instrument's normal playing area.
- So probably the reasons that the ragmakamtar's oud sounds very thin are:
1) upper register - low high range (2nd nylon string) is thin probably because the BACK is not contributing any resonance
2) the mid register (3rd string) is thin because the soundboard is resonating TOO LOW, and therefore not "grabbing" the mids.
3) I think/feel that the fact that there are 3 bridges and 3 necks on this instrument is causing some disturbances in the normally free flowing of
vibrational energy.
- - - -
How to solve these problems?
1) problem one can be helped simply by making a light wood back
2) problem three can be helped by improving the design layout, and getting the bridges more "out eachothers way", and also making the necks and heads
much shorter and lighter.
3) PROBLEM #2: the soundboard's overly LOW resonance (due to it's very large size, and very light bracing...) this is the stickler! However logic
tells me that perhaps this can be solved actually by making the bracing more heavy! On the surface, this would seem very irrational - to try to
increase resonance, volume, and attack by bracing MORE HEAVILY!!! but on the otherhand, with a soundboard which is SOOOOO big and wide, it is also
obvious that this huge plate is going to have a very low/deep resonance... and the only way to make a plate resonate higher is to add more
bracing.
You might just say - "well, why not just make the body and the soundboard smaller?" - but the reason why this can not be done is because when you have
two bridges, they MUST be very far apart from eachother otherwise they intercept and disturb eachothers resonance (what I mean is that the bridge
itself is very chunky, then there is all the string tension - so the result is an area which is VERY VERY STIFF... but a bridge "likes" a pretty
loose area 15cm away from it - not a stiff area like another bridge). So each bridge can NOT be crowded. Therefore that necessitates a very large
soundboard - but then a huge soundboard, WHEN ACTING AS A "WHOLE OBJECT" (as it obviously will do!) will surely have a very low resonance.
I think that the most difficult to question to answer is this:
Bracing a huge soundboard will raise it's general peak tone up to the range of a normal oud -BUT will this "extra bracing" in some way immobilize the
soundboard in critical areas which are necessary for transmitting vibration from one of the bridges to the proper areas of the soundboard?
---the only way to find out is to test it.
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rojaros
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Hello Edward,
my new oud has very thin grenadill ribs interspaced with very thin pear ribs: grenadill is very 'glassy' and has strong resonances, pear is also quite
hard but has higher damping. This help to make the resonance peakes a little more broader.
The necks should be stiff but light (guitar makers use cederella odorata for this purpose; maple is also nice).
A consistent way to find out the real helmholtz frequency (and this allways exist in a cavity, though it might be masked ar so low that you cant
excite it with singing) would be to use a sine tone generator and a loudspeaker, and then slowly sweep the frequency and measure the output energy or
trust your ears.
In guitar construction the air frequency mostly hovers somwhere around F# - G#, so it's slightly higher than E, the lowest regularly played note. That
is certainly for a good purpose. If you put the air frequency lower than that, you might completely loose focus of the bass range.
The top shouldn't be too stiff, but even worse is to flabby. Beeing on the slightly stiff side and then let the time soften it up a bit is probabely
right. That way your trebles will also be better focussed and projecting.
Huge soundboards also seem to be a problem. Often smaller tops sound better than large ones.
Energy transfer through the bridge is quite complex. The torsion is quite an important factor in traditional oud. If you put a great tension on your
top, some doming or concave form (like with turkish ouds) might help to get the working point of the top right.
I don't have a big experience with bracing at all, but you must consider that the static effectivity of making the bars wider is proprtional, whereas,
if I remember right, to make them higher, proportional to the third power. So the way to go is to make them narrow but high; that way you spare mass
without loosing strength. But if you make them to narrow, you'll have some selective resonances, because the bracing acts as a filter suppressing
wavelengths that fall within the width of the bars.
Just again some educated guessing, as I have never build any instrument by myself ...
best wishes
Robert
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Aymara
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Hi again!
| Quote: Originally posted by rojaros |
In guitar construction the air frequency mostly hovers somwhere around F# - G#, so it's slightly higher than E, the lowest regularly played note. That
is certainly for a good purpose. |
That leads me to the question: Should the eigenfrequency of the instrument be dependent of the desired tuning? And wouldn't in the case of the guitar
standard tuning the best eigenfrequency be E, the deepest available note? If not, why?
Greetings from Germany
Chris
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Edward Powell
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| Quote: Originally posted by rojaros | Hello Edward,
my new oud has very thin grenadill ribs interspaced with very thin pear ribs: grenadill is very 'glassy' and has strong resonances, pear is also quite
hard but has higher damping. This help to make the resonance peakes a little more broader.
The necks should be stiff but light (guitar makers use cederella odorata for this purpose; maple is also nice).
A consistent way to find out the real helmholtz frequency (and this allways exist in a cavity, though it might be masked ar so low that you cant
excite it with singing) would be to use a sine tone generator and a loudspeaker, and then slowly sweep the frequency and measure the output energy or
trust your ears.
In guitar construction the air frequency mostly hovers somwhere around F# - G#, so it's slightly higher than E, the lowest regularly played note. That
is certainly for a good purpose. If you put the air frequency lower than that, you might completely loose focus of the bass range.
The top shouldn't be too stiff, but even worse is to flabby. Beeing on the slightly stiff side and then let the time soften it up a bit is probabely
right. That way your trebles will also be better focussed and projecting.
Huge soundboards also seem to be a problem. Often smaller tops sound better than large ones.
Energy transfer through the bridge is quite complex. The torsion is quite an important factor in traditional oud. If you put a great tension on your
top, some doming or concave form (like with turkish ouds) might help to get the working point of the top right.
I don't have a big experience with bracing at all, but you must consider that the static effectivity of making the bars wider is proprtional, whereas,
if I remember right, to make them higher, proportional to the third power. So the way to go is to make them narrow but high; that way you spare mass
without loosing strength. But if you make them to narrow, you'll have some selective resonances, because the bracing acts as a filter suppressing
wavelengths that fall within the width of the bars.
Just again some educated guessing, as I have never build any instrument by myself ...
best wishes
Robert |
HI Robert
I think you need to start building! My educated guess it that your instruments will sound GREAT!
Thanks for your feedback, it is helping me to hopefully solve this riddle. . . .
I think the two main problems with the ragmakamtar are:
1) huge soundboard- BAD (but bridges far apart - GOOD)
2) normal size soundboard - GOOD (but bridges too close - BAD)
How to solve this riddle????
-maybe making ALL strings from both necks coming out of just one bridge??
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Edward Powell
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| Quote: Originally posted by Aymara |
That leads me to the question: Should the eigenfrequency of the instrument be dependent of the desired tuning? And wouldn't in the case of the guitar
standard tuning the best eigenfrequency be E, the deepest available note? If not, why? |
Yes, the peak-note is completely connected with the tuning you want to use. Having the peak-note for a guitar be bottom E is not ideal because
remember that the peak-note is FATTENING a whole RANGE of notes both above and below it. Therefore if the peak-note is E, then you are wasting the
fattening potential coming from this peak-note on the notes below E. BUT if you really like a drop D tuning, then having the peak-note at E or F would
be great because the low D will also sound rich.
Now, relating what you mention to my own experience with the ragmakamtar, and also remember what Fernando said about the instrument play US rather
than the other way around. So, in support of my realisation that the ragmakamtar (because of it's huge soundboard and very light bracing, has a VERY
VERY VERY deep resonance. I have the lowest string now tuned to A (that is the same as an open A on a contrabass!), and I find that I am always
playing around in THIS lowest octave!! And it sounds great! I can hardly pull myself out of it.
Now, thinking further, if I will adjust this instrument's design and bring the resonance UP to the range of a normal oud, then the higher and mid
notes will finally sound full BUT, that deep deep octave that NOW sounds good, will surely suddenly NOT sound as good as it does now.
So therefore, with this new design I probably ought to think seriously about how I want the instrument to be tuned.
Yes, I agree with Robert that I will make the new bracing still narrow, but much much higher - like 20mm as opposed to the 12mm generall in there
now. The current ragmakamtar soundboard is pretty tight around the bridges but very very flexible and bouncy in the other parts.... I have always
had this flexibility as a goal, but finally I realised I took it too far! Or at least, I now know that a floppy soundboard on a huge soundboard is NOT
a great combination!
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rojaros
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Hi Edward, I'm affraid, I have two left hands, as far as woodworking goes - though I love to watch a skilled master.
As to the issue of air resonace frequency: I don't think it should be at the lowest pitch you are aiming at. I think it has a very good reason that
since more than hundred years for guitars it is above the lowest pitch.
People have tried all sorts of body construstions and sizes; but what was laid out by Torres seems more or less to be holding true.
But this of course has something to do with the guitar sound vision: it should have a strong but focused bass capable of projection. And above all
guitar is a polyphonic instrument, which is not the case basically with the oud (apart from the mauro-andalusian music).
Now, let's adress the riddle you formulated:
big top - far spaced bridges versus smaller top, close standing bridges.
First of all: you could have the construction done in a way that the top almost acts as two tops by having an inner wall - if
necessary with some ports to eneable the body to act as a big cavity.
The issue than would be than to shape the top itself (thicknesses - bracings) in a way that it really can act as if it were two tops. That should be
feasible.
Secondly: you also could have a smaller top and bridges standing closer together by reconsidering their construction: make them
lighter, make them arched (not having full contact with the top), using lighter wood, etc. etc. That should be possible because you use floating
bridges, as I can see.
You also could reconsider and use traditional bridges. They function quite differently from floating bridges and have their own merits. They let the
body vibrate more freely when made to proper proportions with a lighter but stronger wood (pear eg.)
One little remark to the issue of the top size: In my discussions with Sebastian Stenzel he often mentions 'larger top', 'smaller top' in relation to
guitars where I barely can see a difference. It seems that every milimeter counts.
Also if the coupling of the top to the sides is stiffer, it makes effectively for a smaller top. So there are some ideas how one could reduce the
effective vibrating area of the top without sacrificing the body size, if the latter has a good reason. But it seems that body size often is
overestimated, it's only one of a few of important factors for how the bass actually works. See all the old Torres guitars; they are pretty small and
have beautifull focused bass.
I enjoy very much our exchange
best wishes
Robert
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rojaros
Oud Junkie
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| Quote: Originally posted by Aymara | Hi again!
| Quote: Originally posted by rojaros |
In guitar construction the air frequency mostly hovers somwhere around F# - G#, so it's slightly higher than E, the lowest regularly played note. That
is certainly for a good purpose. |
That leads me to the question: Should the eigenfrequency of the instrument be dependent of the desired tuning? And wouldn't in the case of the guitar
standard tuning the best eigenfrequency be E, the deepest available note? If not, why? |
Hi Chris, I don't think that is true and it's not very practical, too. You want to have a good instrument that is able to take a dropped tuning.
I have a Hanika guitar that has an air frequency somwhere around G# which in the usual range, even rather on the high side.
But this guitar is unbeatable in dropped tunings. I go as far as tuning it to a cello tuning(!) starting with C (major third lower than the usual
E!!!) and it's just there (if the strings are chosen accordingly).
As I write again and again, there are many interdependent factors that make for a good and flexible instrument and fixating one's gaze on only some of
them would quite likely lead to a construction that is out of balance.
best wishes
Robert
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Aymara
Oud Junkie
Posts: 1162
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| Quote: Originally posted by rojaros | | you could have the construction done in a way that the top almost acts as two tops by having an inner wall... |
Mmh, interesting idea, because that reminds me of the two chamber bodies of Godin and Rob Allen. So who knows, maybe a four chamber body would be even
better for the Ragmakamtar?
BTW ... if you do a research, you can find photos of the inner body design of the Godin two chamber guitars.
Just a thought ...
Greetings from Germany
Chris
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