the acoustic bass vs the contra

Acoustic bass
4 steel strings

The bottom string on hago's Niibori contra guitar is an octave below an ordinary guitar.
It's the same pitch as the electric bass guitar and its cousin the acoustic bass guitar (pictured left).

But the Niibori contra (pictured right) is very different.
It has 6 strings (E A D G B E) compared to the acoustic bass's 4 (E A D G).
Although there are occasional 6-string basses, their tuning is generally B E A D G C.

The scale length of the Niibori contra is 750mm, a long-scale acoustic bass is 864mm.

The string tension is different - nylon, at about 20 pounds, rather than steel at 55 pounds.

The body size is different - the hago contra has the chunkier, deeper, body and the bridge is in the centre of the lower bout, where it couples best to the fundamental, rather than the overtones.

Which all adds up to a rounder, deeper sound and more volume.

The Niibori contra, played in ninth position, sounds remarkably like a double bass.
The acoustic bass has an extended sustain but a thinner, punchier, sound.

Contra guitar
6 nylon strings