# Octaves, Zouks, Citterns, Tenors and Electrics > CBOM >  sizes for gdae octave pairs on mandola?

## tarvoke

so, a while back I got a very nice gervaise troubadour from forum member bratsche. just made sense to me as a decades long student of viola (yes yes lol, da braccia, etc.)

but in terms of playing, going up a 5th to violin/mandolin tuning has started to feel easier - my favorite these days is a puerto rican cuatro, de-tuned to gdae (upper 5th course removed)

and what I really enjoy about the cuatro is the sound of the octave pairs on the 2 low courses. well that and the much broader neck is easier to handle.

so what I'd like to get opinions on, is not just what strings to use for gdae on this mandola (15.8", or so, scale) but also size for bringing 1 of each pair up or down an octave. (heading to some string calculators now, but any input most welcome)

many thanks

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## Mandobart

I would not recommend it; the standard 'dola tuning works better with the scale and body size.  That said, I would use one of the many string tension calculators out there and find what the tension would be using the builder's recommended strings in standard tuning.  You'll need to plug in the scale length of your dola (nut to bridge length).  Then, select lighter gauge strings that will allow the tuning you want while maintaining the same tension as calculated above.  The E can be a problem; on my 16" 10-stringer I use .0095" for the E.  It's hit and miss whether a .010 will hold up tuned to E.

The octave pairs are easy enough; I've done this on several instruments.  A good rule of thumb is to simply halve the diameter when doubling the frequency.  That is, your octave higher G should be one-half the diameter of your standard G and so on.  Another easy way to do it is use an "A" string tuned down a step to the octave higher G, and an E string tuned down a step to the octave higher D.  I've tried octave pairs on many instruments; love the sound on my OM and mandocello.  Didn't really like the sound on the mandolin, though.  For that reason I never tried it on my mandola.

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tarvoke

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## tarvoke

thanks Mandobart! yeah wow, I do remember enough basic physics that I feel pretty embarrassed not to have thought to simply halve (or double, on higher courses) the diameter - no calculator really needed.

I absolutely love the sound of octave pairs, and lately I've just felt regular mandolins are a little too shrill.

I feel like because this model is so light and shorter scale, I've read somewhere in the past about troubadour recommending OM tuning for it as well? but also just looking for an excuse not to sell it - strings feel too heavy and neck feels too thin. but I know somewhere around here I have some .009p guitar strings that have always scared me too much to try...

but now, I think what I may try instead/first, is to convert my dgae baritone ukulele to an 8-string - assuming the glued bridge will hold, maybe it will also require changing the bridge to an endpin supported type.

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