Trouble forming octaves with hand?

I have this on V-shaped necks.

 

thumbposition?

 

I go for keeping the arched shape of my fingers within their comfortable spread rather than over stretch strain and stiffen the hand. This means that when I am in the lower positions I use a half-stretch half-pivot. The first note gives a reference point from which to stretch with momentary discomfort. It is a system that I have used for a long time and my LH does not tire easily. I'm sure that I am not alone.

 

"The hell of the neck." An apt description for double bass.

 

A too long string length is one thing that makes the interval more difficult. Music that may require a lot of I-V and I-Octave ostinato, like latin, jazz and roots music, is more difficult and tiring to play if the finger reach is too long for your hand.

 

Ain't that the mischief of it! Flies right in the face of "conventional wisdom." I'm having to narrow the distance between strings at the bridge simply to accommodate speed pizzicato.

 

But with that neck and string spacing and similar setup, I bet the 40" SL would be even easier to play, unless your hands are huge!

 

Another series of factors are to do with the size, shape (outline and swell/flat back) and dimensions of the body of the bass that influence how you sit/stand to play. I am hopeless with the Hawks Panormo shape.