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Hi all, it's been years since I was last on here. I'm embarking on a new project to build a 23.5" scale acoustic bass for my 11YO daughter. I'm looking for some direction as this is a new beast for me. A bit of background; I've built 16 acoustics over the years (so I have a reasonable idea what I'm doing and a few electrics, but never a bass.

The string tension is around a third of what I would usually get on a 6-string; 50.2lb vs 148.5lb. Build will be sitka, mahogany b&s and neck, with ebony fretboard and bridge.

Any advice or experience to guide me on changes to bracing patterns, brace heights, string spacing and relief would be appreciated. Even a link to a suitable source, as I'm finding little on my search of the interwebs.

Shane, It sounds like you're trying to emulate a Taylor GS Mini bass. I think it would be useful to handle and play one before going too deep into a build project.

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Peter Havriluk

Acoustic bass guitars are notorious for being too quiet to compete with more than one guitar played gently, as the body volume is too small. My upright bass is barely large enough for a strong low E!

So you should plan now for amplification, probably a SBT is most natural sounding.

Another issue will be strings - I played a short scale electric bass years back, probably a 26 inch scale, and intonation was a real ssue. Shorter, fatter strings will be worse.

That said, the strings developed for the larger ukulele basses might be worth checking out.

Standard X bracing would be my guess for building, but I have no experience of making an acoustic bass guitar so can't offer other suggestions.

I’ve built a few acoustic basses with 33” and 34” scales. In order not to make the body way too big, I designed them to have a strong second harmonic so that the ear could fill in the missing low fundamental. It worked quite well. Standing in front, the basses sounded as loud as my upright on the low notes. Standing behind, the volume was quite a bit weaker. The low notes from the upright filled the room. The loud second harmonic was much more directional.

I bought a Fender 30” scale bass just so I could play with the shorter scale and decide if I wanted to make a 30” scale acoustic bass. I wasn’t pleased with the behavior of the low strings at that length, so I haven’t done anything with the concept yet. You string length is even shorter. If you solve the string problem, the second harmonic approach might give you some apparent volume.

Please report if you find a way to do it.

Just checked out the Kala U-bass. It has a 21 inch scale and is reported to work quite well when amplified. Its strings might work for your project.