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Max Girouard
02-08-2016, 10:11 AM
I'm designing myself a tenor, and noticed that many ukulele's have tapered bodies similar to guitars. Coming from mandolin building, I'm used to the rim being the same depth at the tail end as it is at the neck end. Other than aesthetics or because it has always been done that way, are there any opinions on why they are tapered?

BlackBearUkes
02-08-2016, 02:53 PM
They direct the sound better, they look more professional and pleasing to the eye, are easier to hold and they fit the case better


I'm designing myself a tenor, and noticed that many ukulele's have tapered bodies similar to guitars. Coming from mandolin building, I'm used to the rim being the same depth at the tail end as it is at the neck end. Other than aesthetics or because it has always been done that way, are there any opinions on why they are tapered?

Red Cliff
02-09-2016, 11:27 AM
I have never really heard a great reason for it other than tradition. For a guitar you could argue that due to size it is more comfortable and fits the body better, but on a ukulele? Fit the case better is true, but then I'm guessing that cases are made the shape they are because everyone makes ukes with a tapered body... chicken and egg stuff. Directing the sound better seems to make sense, driving air and sound from a large area through a small area - only brass instruments do the opposite, driving air and sound from a small area to large and they sound and project just fine. I have actually made classical guitars with and without taper, and even reverse taper, and honestly I couldn't tell the difference in sound, although admittedly it wasn't a scientific test. I reckon tradition is just about right.

mikeyb2
02-09-2016, 11:35 AM
I'm wondering whether it was done originally to prevent the back from dipping if it was built flat. The top wouldn't need this so much as the tension from the strings at the bridge would help pull it upwards. Just a thought.

Michael N.
02-09-2016, 12:23 PM
I'm surprised that Mandolins aren't tapered, given that they take a lot from Violin making. On Violins it's a very, very small taper. I think the question came up on a Violin makers forum once and no one seemed to know the answer. The taper certainly goes back a long way, it can be found on instruments nearly 400 years old. On a Viol there's a very abrupt taper, maybe the same with the double bass.

ksquine
02-10-2016, 07:01 AM
Bowl back mandolins look like a pretty extreme taper to me....kinda fails at making it easier to hold though.

Max Girouard
02-11-2016, 03:35 AM
I did a fair amount of research as to why guitars are tapered and could not find any conclusive data stating what the actual purpose was. I'm assuming that ukulele construction incorporating the taper, is just a carry over from that building tradition. I'm not too familiar with violin building, but I did dig out my plans on the Stradivarius "Titan" and "Messiah" violins and there is variation from the tail block to the head block of about 1-2 mm on both of them. There also shows up a fair amount of deviation (plus or minus .5 mm) around the point blocks. Interesting stuff. Bowl back mandolins are not easy to hold that is for sure! I'm coming from a background of modern mandolin building where the rims are of even height all the way around. The same is true with most modern archtop guitars that I've studied. I'd be interested to hear from anyone who has built both tapered and non tapered uke bodies and what their thoughts were regarding the differences between the two. I'm on the fence about making mine non tapered vs tapered.

chuck in ny
02-11-2016, 05:32 AM
from another perspective, is there any perceived advantage from not tapering and having a larger cavity, in the extreme example a cigar box build.
how do such instruments sound as i've never played one. the comparison would be a good inkling on whether to taper or not.

Red Cliff
02-11-2016, 10:44 AM
Whether you taper or not you can make the cavity as small or large as you want, just make it or shallower or deeper accordingly. You can work out the volume of a tapered body and what depth the sides would need to be for a non-tapered of the same volume and vice-versa.

But generally, and all things being equal, a larger cavity means greater volume and bass, or at least it can if done right.

sequoia
02-11-2016, 06:20 PM
The way I see it, if luthiers have been tapering their bodies for more that 400 years there must be something there besides simple tradition. What is there is that a straight box sounds, well, boxy. Doh... By tapering the vibrations coming off the top with a body taper forward, it tends to cancel out unwanted sustain. Especially those pesky and annoying treble overtones. The question in my mind is not taper per-say, but how much and where? I've never figured this out and nobody has ever stepped forward and made a definitive statement. Les is probably Moore.

Michael N.
02-12-2016, 12:44 AM
This unwanted sustain. Do you know for certain it's a direct consequence of a body that does not have the taper feature and how have you reached that conclusion? I'm not trying to be contrary just for the sake of it but it always seems to me that there are so many variables when comparing any two instruments. The best we can do is measure (as in science) or build two instruments as near identical (consecutive cut wood) and then put the two in a blind test. The only other alternative would be to get a great many examples of each type and then recognise some sort of trend. The latter being prone to confirmation bias. Come to think of it things get even more complicated. I can think of many folk who may positively enjoy those pesky annoying treble overtones.

sequoia
02-12-2016, 07:01 PM
As for the unwanted sustain Michael, I do not know for certain whether it is a consequence of body taper or not. I actually have no facts to support that assertion whatsoever. Actually I'm just following tradition. Now I could build two ukes as close to identical as I could, one having no taper and one having taper and compare the two sounds. However, I have limited resources in terms of money and mostly in time and I feel deeply that the untappered uke would be a wash and a failure. Call it a priori knowledge or what you will, but I ain't goin' there.

Max Girouard
02-14-2016, 11:13 AM
I think I might go there. I've got enough for two out of the same board, so the woods will be pretty similar on each build. If it sounds bad, I'll have to take the back off the non tapered instrument, put the taper on and re-glue the back. Of course I'll have to do all this prior to finishing, but it will make for a great experiment.

BlackBearUkes
02-14-2016, 03:34 PM
Good luck with this experiment, but I sincerely doubt you will hear any difference at all. As for addition sustain on a tapered side or non-tapered side uke, again, very doubtful. Lots of things can help sustain, but a bit more air volume in the upper bout ain't gonna do it in my experience.


I think I might go there. I've got enough for two out of the same board, so the woods will be pretty similar on each build. If it sounds bad, I'll have to take the back off the non tapered instrument, put the taper on and re-glue the back. Of course I'll have to do all this prior to finishing, but it will make for a great experiment.

sequoia
02-14-2016, 04:27 PM
As for addition sustain on a tapered side or non-tapered side uke, again, very doubtful. Lots of things can help sustain,

Just a thought here, but more sustain is not necessarily a good thing. It can actually be a bad thing. The function of the tapered upper bout maybe to actually decrease sustain. Think of playing a piano with your foot on the sustain pedal the whole time, the notes start to collide and the sound becomes a messy stew of vibrations. I believe that the tapered upper bout acts as a sort damping pedal on overactive sustain. Now that being said, if the uke is so poorly constructed that it can barely produce any sustain at all (i.e. the infamous canoe paddle), than lack of a taper might be a good thing. The effect on sound may be subtle with taper, but it is the sum of subtle factors that might be what makes a merely good sounding instrument into a great sounding instrument and I think taper is one of those subtle factors. Also I think 400 years of luthiery experience and practice is something that is not to be taken lightly. Lloyd Loar where are you when we need you man? Being dead is no excuse.

Sven
02-14-2016, 09:37 PM
You need Lloyd Loar to tell you the difference between a ukulele and a piano? Ha ha ha - you crack me up. Often when I play I fret the strings to form chords, thus killing any booming endless sustain in my uke far more efficiently than any body taper ever will.

Seriously sequoia - I admire the work you've shown, but this a priori knowledge freebasing, what's it for?

chuck in ny
02-14-2016, 09:56 PM
there is form and grace in shaping the instrument as a taper from larger to smaller. the original builders who incepted this likely thought it was lovely. then of course you have consumer expectation and some small improvement in ergonomics. that's enough.
next thing we can complain about pretty girls.

sequoia
02-15-2016, 05:20 PM
Next thing we can complain about pretty girls.

I never complain about pretty girls. Ever. Never enough pretty girls. However Chuck, I think there is more to taper than just aesthetics. Why? Because basically it is a pain in the ass to do and the buyer never notices anyhow so it had to have acoustic meaning if they have been doing it for 400 years. At least that is my uninformed, unlearned and perhaps miss-guided theory. The reason I do taper is because my design plan (blue print) says to do taper and I am a slave to my design plan which I assume (and hope) was done by someone who actually knows what they were doing and knew something about actually designing an acoustic stringed instrument which I do not. I'm assuming it is like a word from Pete Howlett: Just do it! Don't ask questions! Just do it! It will sound great!

Now as to freebasing a priory knowledge: I'm totally in favor of it.

ChuckBarnett
05-23-2017, 06:11 AM
"a priori" knowledge... haven't heard that one since college. :-)

ChuckBarnett
05-23-2017, 06:29 AM
I'm new to this. Is it a gradual taper or is it a straight line? I have an LMI plan for a tenor that calls for 2 7/8" down to 2 5/8". It appears to be a straight line but??

sequoia
05-23-2017, 05:52 PM
I used to think about this a lot too. In the beginning I tapered more sharply to the bout than had a more gradual taper to the end block for the lower bout. After awhile I realized I was over thinking the situation and now just do a straight gradual taper neck to tail. Subtle. 3/16th to 1/4 overall over 12" (1/4" / 12"). I've actually never got a real answer to this question from a real instrument designer and I've asked. A big shrug is all I ever got. Whateva... Is it important? I think it really could be. The problem is, it all gets really complicated.