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Hello friends
i hope all of you are doing well and happily building guitars

Till today i have built 3 OM guitars. and building my 1st dreadnought on D28 plans
the top is braced and voiced and sounding good but i think its weight is too much
im using kent everett method of wider and short braces .
the weight of my top is about 310 grams.
can anyone tell me wat should be the general weight of voiced dreadnought top??
waiting for ur advice.
thanks in advance

Hi Rahoul,

Bumping your topic back up the list.
I have no answer to your question as I have never weighed a guitar top.


Steve

it seems to me that the weight of the top is determined by the voicing. If it's properly voiced, I don't understand how you are going to reduce the weight. I suppose you could trade stiffness between the top and the braces by making one stiffer and one less stiff, but that doesn't seem guaranteed to reduce the weight or maintain the voicing

Hi Rahoul . My deadnaught tops range from around 270g to 300g.
My OM tops range between 220g to 250g. Also don't forget by the time you trim to final size and sand ready for finishing you will most likely loose another 10g or so depending on how much oversize you have it at the moment.

Regards
Craig.

Thanks friends for ur replies. i know it was stupid question so not got many replies

but special thanks for mr. craig who gave me the range of weight of top of both OM and dreadnought.
but sir this is weight for sitka? what will be range for engelman and red cedar?

It's not a stupid question. The problem, basically, is that it is too open ended. So many different factors can, could, and do influence the weight of the top that your question is actually very difficult to answer.

I feel that there are more useful and important quantifiable variables than weight to determine your top dimensions. I feel that the end weight should be a byproduct, not a specific target. Much like final thickness should be a byproduct of flexibility, not a specific target.

There is a wealth of information about quantifiable data in the Gore/Gillet books, I can't recommend them enough.

While I certainly believe building "light and tight" is a good way to help prevent constructing a real dog -- I don't think the free standing top weight alone is necessarily a good metric to predict final sound quality. I do brace shaving after the sound board is attached to the rim and perimeter thinning after the body is assembled. Both based on my "imaginary skill" of tap tuning. I do think that anyone can hear the difference in an assembly that has good resonance and one that is too stiff and unresponsive.

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Ken Cierp

http://www.kennethmichaelguitars.com/

I weigh my tops too but it's really just an exercise in data collection. I only recently started doing deflection testing and my understanding of it is that it is a more important metric and of course will affect the weight of the top. If you start off with really stiff materials then in theory you will be able to thin them to your specific deflection range which will reduce the weight. I like deflection because that sort of rules out the materials innate stiffness and density variables. Just measuring the weight of the top doesn't really give you much value imho, still good to know though.

I do consider the weight to be an important variable, and I control it by varying the proportion of plate stiffness to bracing stiffness. My current belief is that the tone of the guitar is largely determined by the size, mass distribution and stiffness distribution of the complete soundboard (including braces/bridge/pins/saddle/finish). I haven't really collected enough data to say anything for sure, but my intuition is that for 12 gauge steel strings, the total soundboard mass (including bridge and everything) should be max 300 grams. With small to medium size softwood soundboards that's virtually guaranteed, so then you really can ignore it, but not so on large ones or hardwoods.

My 000 rosewood top is almost precisely 300g, and it sounds good, and surprisingly normal. So it seems like a confirmation of my theories, since it's extremely thin, but elaborately braced to make up the stiffness, and the density of the rosewood brings the mass up to a normal level. If I could magically transform the rosewood into spruce of the same thickness, the stiffness would be more or less unchanged, but the mass would drop by ~90g. Bet it wouldn't sound so normal then!

Is your bracing scalloped? I think that's better for high mass soundboards, because it tends to let the bridge move without having to drag the entire soundboard along with it the way tapered bracing does. I'd recommend making a lightweight bridge. Perhaps walnut with the thickness tapered toward the back edge. And use lightweight bridge pins like wood or plastic rather than bone. And probably do some perimeter thinning too. Probably won't reduce the mass much, but the stiffness of softwoods is usually somewhat proportional to the mass, so your plate stiffness is probably on the high side, and perimeter stiffness is controlled more by the plate than the bracing. But I'm really just guessing here, so take this advice with a grain of salt

300 grams is not out of line for a Dread top. Most of the weight is in the top itself, and depending on the density you can shave as much as 20% off by choosing the right set of wood, assuming you work to a constant stiffness. I find when I'm 'tuning' braces that I seldom take off much more than 10-15 grams going from 'clearly too big' to 'just right', so maybe 1.5% of the total in an extreme case. Generally speaking, a heavier top will give up a bit of power, but that may not make much difference in how loud it sounds up close. A lighter top will tend to be more 'responsive', but may lack something in 'headroom'. Light tops, particularly ones with scalloped bracing, could be more prone to 'wolf' notes, so if you're going for that 'Martin thump' using a denser top with scalloped bracing should be a good idea. In short, as the Brits say, its a matter of 'horses for courses': figure out what sound you want, pick the top accordingly, and then work it down to the 'correct' thickness and put on the 'right' bracing.

friends im very much glad that i got so much responses.
i will try the deflection method too.
and yes the top has scalloped bracings.
hope it will make a good guitar.
really thanks for ur help

I am familiar with "wolf notes" that occur on bowed instruments and have heard samples of the phenomenon. They are pretty annoying and unmistakable and fortunately fairly simple to eliminate. Is there guitar wolf note Youtube video or other audio sample available? I would not know what a Guitar "wolf note" is if it smacked me in the ear.

Thanks

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Ken Cierp

http://www.kennethmichaelguitars.com/

Ken,
I think the term is a bit of a misnomer when applied to guitars. Hearing one on a cello might lead to you believe there's a sea lion in the room, but on a guitar it's more of an unusually loud note that has little sustain. Not as severe as bowed instruments, but undesirable nonetheless. Of course, a little unevenness in response does keep things more interesting.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

I always thought the wolf note on the guitar was the note at which the guitar body naturally resonates on, the sympathetic vibration. If you play the same note that the guitar resonates at then it's amplitude is greater, louder, but the note fades faster too.

The usual 'wolf' note on the guitar is the 'thuddy G'. The 'main air' resonant pitch is close enough to the frequency of the G note on the low E string that it can extract energy quickly from the string and convert it into sound. You get a note that is twice as loud for half as long, and since we don't notice absolute power as readily as the presence or absence of the sound all we notice is the lack of sustain.

In terms of the way the string and body are working, this is almost exactly the same mechanism as the 'wolf' on a 'cello. The outcome is very different primarily because the bow inputs energy constantly, while a plucked string normally dies out more or less quickly anyway. On the 'cello motion of the bridge at the fundamental frequency of the string means that the reflected wave from the bridge that normally provides feedback to maintain the stick-slip motion of the bow is too weak to keep the fundamental going, so the string shifts up an octave in pitch. When that happens the resonance that causes the problem dies out, and the bridge once more becomes an effective end for the string at that frequency. When this happens the string shifts down to the fundamental again, the energy of the problem resonance builds up and the whole problem returns. It's the cyclical shift up and down in pitch that causes the 'roaring' or 'bleating' sound of the 'cello wolf, but the mechanism is the same as the much less bothersome guitar variety.

As far as I'm concerned, there can be lots of different 'wolf' problems on a guitar; the thuddy G is just the most common. Basically, any time you have a couple between resonances that causes a problem note that's a sort of wolf. Guitar wolfs often sound like fret buzzing. They can be extraordinarily hard to track down sometimes, but are usually pretty easy to remedy once you've found the cause.

Hi Rahoul-

I bought the braced top from the Kent Everett voicing video. It is at .109" thickness and weighs 281 grams. The bracing is like you describe - wide and low - he doesn't triangulate. The top and bracing are Sitka spruce. I'm of the same mind as most everyone here - weight isn't as big a factor as top deflection and how you carve the bracing. Since you mentioned you are using Kent Everett's methods and I happen to have a top that Kent braced, I figured I would show pics and give the weight and thickness. Good Luck!



All the notes on the underside of the top are mine - I measured and marked everything as I watched the video.

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John Lewis
Wannabe builder owned by 2 crazy dachshunds

Thanks sir for the foto. its really useful