Tonal differences?

[John Bertotti]

OM or Mandola, I have a question. I have never played either in a guitar shape or traditional A or F shape, my question is tonally does the guitar shape vary much from a traditional? My idea of traditional shape may not be traditional just how I see them in my minds eye.

Maybe I should elaborate a bit more. What points do you consider before choosing the body shape?

[RobH]

I can't really say anything about the tonal differences between an A shape OM and a GBOM, but I think an important factor to consider is scale length, since that will dictate what you can play and how you can play it. I just completed a smaller GBOM with a 13" lower bout and 21" scale and I'm very happy with it. I have long fingers and I can put my index finger on the second fret and ring finger on the 5th fret- basically mandolin fingering- so I can play fiddle tunes in first position without too much trouble (but still with a lot of shifting). As for body shape, I think it depends on the type of music you play and players you admire. If you play Irish Trad I'd go with an A style, but I like the look of a GBOM and the players who use them. The other consideration is the price differential between the styles. BTW I'm really enjoying my OM to the detriment of my mandolin playing.

[RobH]

One other thing to consider is the difference between a flat top and a carved top OM. That might make more tonal difference than between an A style and a GBOM

[EdHanrahan]

OM or Mandola ...

Sorry but, I find the premise of the question perplexing.

- Mandola is, IMHO, 25% different from mandolin: drop the high E string and add a low C string, while;
- OM is, effectively, 100% different from mandolin (or maybe 50% depending on your viewpoint); lower every string by an octave.

So maybe an OM is 75% different from mandola? Again IMHO, mandola "sounds" fairly close to mandolin, while OM "sounds" fairly close to guitar. Whatever the tonal difference based on body shape would seem trivial compared to the difference in range, scale length, string mass & tension, intended purpose, and maybe playing technique. (Edit: Sorry to partially repeat Rob's thoughts above.)

Or am I missing the point?

[Tavy]

To reiterate what others have said, the body shape is much less important than construction - flat top vs archtop, f vs oval holes, and floating vs pin bridge.

So a flat top instrument with a pin bridge and oval hole would sound most guitar like, while an archtop with f-holes and a floating bridge would be at the other end of the spectrum regardless of body shape.

[John Bertotti]

Didn’t mean for this to be perplexing and I understand the differences between types of instruments ie om vs mandola vs mandolin. Tou using in just on one instrument he it Om or mandola I was curious if the body type in that style of instrument made a difference.

So, all things considered if I pick the mandola, I have a beautiful piece of wood and want to pick what body shape to run with, are the differences in tonal response between the style of body. It will be an arched top floating bridge whichever way I go. As an example I would think a guitar shaped body might have a better bass response than say the A shape, just a what if, I’m not saying it does. I am just curious. I do have a nice piece of wood for a top. I have asked questions about it before as a mandolin but it is big enough that I feel it would waste some good wood on a mandolin sized instrument. Since I would like a mandola or OM what points would you use to pick the body shape? I have small hands so an OM may not be the way to go but I do love the sound of a mandola. Tonally will my decision in body shape influence the tonal qualities enough that it might lead me to pick F over A or Guitar shape over F or A. The wedge is big enough to go as large a an 0 sized guitar body, if I am very cautious. I think. Thanks for the replies so far and apologies if it wasn’t very clear. I just want to pick a shape that will give me a nice balanced tone all around and thought one body shape might move me in the correct direction more so than another.

[RobH]

I don't think anyone can give you a definitive answer to your question. If you can't play these styles in person then the next best thing is to find examples being played on YouTube to see what you like. As for having small hands, watch Sierra Hull on OM. Also you're allowed to capo an OM and at the 5th fret you have a mandola.

[John Bertotti]

I don't think anyone can give you a definitive answer to your question. If you can't play these styles in person then the next best thing is to find examples being played on YouTube to see what you like. As for having small hands, watch Sierra Hull on OM. Also you're allowed to capo an OM and at the 5th fret you have a mandola.

You are correct there is no instruments of this type around me to play. I think instead I’ll do as suggested listen to some music with said instruments and go from there.

[Tavy]

So, all things considered if I pick the mandola, I have a beautiful piece of wood and want to pick what body shape to run with, are the differences in tonal response between the style of body. It will be an arched top floating bridge whichever way I go. As an example I would think a guitar shaped body might have a better bass response than say the A shape, just a what if, I’m not saying it does. I am just curious. I do have a nice piece of wood for a top. I have asked questions about it before as a mandolin but it is big enough that I feel it would waste some good wood on a mandolin sized instrument. Since I would like a mandola or OM what points would you use to pick the body shape? I have small hands so an OM may not be the way to go but I do love the sound of a mandola. Tonally will my decision in body shape influence the tonal qualities enough that it might lead me to pick F over A or Guitar shape over F or A. The wedge is big enough to go as large a an 0 sized guitar body, if I am very cautious. I think. Thanks for the replies so far and apologies if it wasn’t very clear. I just want to pick a shape that will give me a nice balanced tone all around and thought one body shape might move me in the correct direction more so than another.

OK, now I understand what you're asking. Your shape may be determined by the size of the wood blanks: you need to adjust the body shape and soundhole size to place the body resonance at the right frequency, so if I were you, I would sketch out some designs, calculate body volume range (based on possible body depths given your rib sizes) and then matching soundhole sizes for each rib size. For each body shape that will give you a family of related designs that you can include/exclude based on aesthetics (as in "oh my god that soundhole doesn't look right"). Then after that, larger body volumes tend to be louder, guitar shapes are nice to hold but prompt "what's that funny 8-string guitar" questions, so that may well shape the decision as well.

As for tone: body volume, total top area and correct placement of the helmholz resonance are the main drivers. Plus every little trick you can bring to bare to reduce loss of energy to non-sound-generating-vibration. Based on my mandolins, I thought for a while that my mandolinettos had a thicker more positive tone around the bass end... and then I recently built a more regular oval and it sounded much the same, so I concluded it was me (and the way I build them) that was evolving, not the designs. But that could be wrong too

Do let us know how you get on!