I recently bought a Rathbone type 4 shortscale acoustic bass. I would like to replace the bronze phosphor strings. Although acoustic, I normally play it through an amp for small gigs.
Can anyone recommend alternative strings for this bass.
The Rathbone No. 4 (R4SME) bass, which I wasn't aware of, has 23" scale.
Rathbone No.4 R4SME Baby-Bass
For this type of instrument, see this thread
Guitar Scale Acoustic Basses
Most of these come with nylon-core, phosphor-bronze wound, micro-coated strings by D'Addario - either the old EXPPBB190GS or the new XTB3790GS set (difference is probably in the coating type). A handful have conventional, steel-core bronze strings. Can you confirm which is the case for the Rathbone? Are the strings somewhat twisty (do they roll under the fretting fingers, especially when pressed at midpoint, 12th fret)?
If so they're nyloncores. You could either order the D'Addario set, or try a popular alternative (La Bella CB40BE). More possible alternatives listed here (in, but not limited to, my posts):
Acoustic bass 25.6" scale
If they're steel-cores it gets trickier. The aforementioned handful of instruments that use them don't really have an aftermarket option: they order OEM versions of ABG string sets from a manufacturer, with the lowest strings appropriately tapered between nut and tuning post, but they don't make the result available for the public, so if you buy one of their basses and the time to change strings come you're SOOL.
Still, you could try getting a light-gauge, standard-scale bronze set like the Ernie Ball 2070 Earthwood Acoustic Bass, and see if the 095 low E fits in the tuning post slots even though untapered.