I do have a question for other OLFers. Is there a consensus on whether or not to taper the upper x-brace arms? I don't because that's how I was taught, and it makes sense to me to keep the upper arms full strength because that's the area of the top that wants to fold in under string tension.

Beautifully crafted John, great work.

Very clean work, John. It looks good to me. I often see photos of top braces that look a good deal heftier than needed, IMO. Yours don't look like that to me.

Do you plan to reinforce the x-brace joint?

I do have a question for other OLFers. Is there a consensus on whether or not to taper the upper x-brace arms? I don't because that's how I was taught, and it makes sense to me to keep the upper arms full strength because that's the area of the top that wants to fold in under string tension.

Just curious! No sound hole reinforcement? No bridge plate? Or maybe this hasn’t been installed yet?
Your bracing looks quite nice, very clean work.

I'd add some soundhole braces. It will probably dip there due to the long distance between upper X legs and upper transverse brace.

The lower X legs could probably use some more carving, but you could wait until it's strung up and do that through the soundhole so you can hear the difference and measure the effect on bridge rotation.

Same. I only carve them down in the last inch or two before the linings, and notch in at about 1/8" tall.

Looks good!

The pic doesn’t quite show the full lower bout, will you tuck the X into the linings or taper it to zero short of the lining?

What is the radius of the top and braces? Are the rims radiused the same to receive the top or left flat?

Cool project!


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John—

This isn’t mud; more like a little cold water.

Can you tell us the setting(s) in which this instrument will be played, and whether it will have a pickup and amplification for regular performances? I ask because what you should do going forward may depend a lot on the answers to these questions. Acoustic bass guitars tend to be played in ensembles, and due to the limited size of the resonating chamber (compared to the notes being played on the lower strings), they tend to rely on pickups through amplifiers to be heard.

It does appear to be very clean work so far! Well done.

I would add a bridge plate extending in front and behind the bridge to help maintain the shape of the top. Otherwise the top could deform into an S shape, dipping in front on the bridge and rising behind it.
Nice clean work! I hope it’s a great success!

Thanks Cal. Sound hole reinforcement is on my to-do list, the bridge plate isn't. I'm going to do a pinless bridge, so my thinking is it's probably not needed. Do you think that sounds right?

Doing it through the soundhole once strung up is definitely the plan. Though I'll admit to never actually having done it before. I'm guessing a finger plane or 80/120 grit sandpaper, do you think that sounds right? Is it...ummm...hard?

I feel as though I've got decision exhaustion. Who knew one tiny guitar could demand so many critical decisions

It's designed to be played acoustically, for practise at home and possibly (just possibly) with a soft-playing guitar person. But as you say, a pickup is probably a good option to have....

So I'm going to build it without a pickup, to begin with. But..... Previous acoustic bass builds have had a Fishman UST and a K&K soundboard pickup. So for this one I was thinking of trying something like this:

https://schaller.info/en/oyster-d-s/1605-D

Basically a pair of stick-on transducers that I can move around to compare how the sound changes depending on location. I can then CA glue it to the inside once I've found the optimum location. That's the plan anway. (Probably coupled with an external preamp).

I've built three ABGs, one had a pinned bridge the other two pinless. I referred to a plan by Mark Stanley for the bracing although the bodies were smaller than his plan (J200 and 0000 Martin). His plan had a substantial bridgeplate with a pinless bridge so that's what I used on all of them.

My point in asking is that, since acoustic bass guitars tend to need pickups and amplification to be heard, I would favor structural stability over trying to get the most acoustic tone possible. We always are trying to balance between the two, and for this sort of instrument, there's only so much acoustic sound available, so I wouldn't do much more carving in order to try to make it sound better.