Un-notched F-holes - bridge positioning method?

I'd look for the witness marks in the top finish where the feet were. Then once you get it positioned I'd run a pencil round each foot to keep track of where it is.

 

Put the bridge in and set it vertical to the table. Use a long ruler (easy) or tape measure (harder) to find the scale length for your instrument on the string; that's the point where the strings come off the top of the bridge. Make sure the bridge is vertical again, and you're there. Mark the position of the feet if you like, but the important measurement is the scale.

 

If it's a 3/4 bass, the mensure is usually 41.5-42". You can check this against the position of your soundpost, which is usually placed nutward of the foot by about one post diameter.

 

If it's close and you have other 3/4 DBs with a scale length that you're used to, you may as well match them since it sounds like you're going to setup the sound post anyway.

Within a standard range, it seems that you have no other reliable landmarks to go by.

 

Maybe if you share the make/model of the bass, someone may have one and can measure the scale length or might know what it is.

 

oh my bad, i missed the no-name part in your post. interesting article, hope it helps.

 

What about the obvious?
Middle of the f-holes?

i would not reposition the soundpost unless you tried the best bridge position with the current soundpost location. If the bridge is close to the middle of the f-hole then, measure and write down bridge and soundpost position and feel free to experiment after that.

Personally I would keep the soundpost where it is and try bridge position relative to the soundpost for best sound and keep it that way.

 

It seems reasonable that you would go off the current position of the sound post, since your description seems to indicate the bass sounds and plays well in it's current configuration.

I was under the impression that the sound post and bridge could be moved around a bit to vary mensure. For example if you have a huge old bass, you might install a false nut and reposition the bridge and sound post. Here's a related thread Is there a way to shorten scale length?

The point is it's probably not all that critical that you get the bridge and sound post in specific position, that would be indicated by the F holes. Instead you have a reasonable range of adjustability in which to make the bass sound and play well.

 

Would there be anything to be gained by chiming the octave harmonic and moving the bridge around until the stopped octave and the harmonic matched?

 

??? AFAIK both will be at the mid point of the vibrating string. If you move the bridge, the mid point move on the fretboard, and so do both the octave harmonic and stopped octave.

 

On every bass I’ve owned the sound post is set below the bridge - toward the tailpiece, not the nut.

 

Won't help, no frets.

 

You're correct, of course. Me writing too fast again ....

 

Step 1) Checkout this video from Upton about setting your bridge

Step 2) Don't overthink it.




As a side note: I installed a few of those in house made Upton bridges several years ago. They worked great and I liked that they were manufactured at their CT shop. It sure would be nice to have them available again to other luthiers. Much (most?) of the country is sold out of the traditional European ones right now and I'm constantly asking all of the suppliers if we are ever going to be able to buy them again while empathetically listening to their current stories about viruses & customs & economics & the state of the world....

 

Two observations not mentioned yet. The first is to check the inside of the belly (front table) for pencil lines drawn by the maker, using a torch and swivel-headed mechanic's inspection mirror. If there is a line across it may indicate one of two things. It could indicate the highest point of the bass bar or, less likely, the top edge of the sound post setting.

The centre of the feet of the bridge should be in line with the missing inside notches that are usually in line with the highest point of the bass bar. Assuming that the two sound holes are carved symmetrically you could approximate the inside notch with a square ended ruler on the bass bar side and make the same mark on the other side then connect them with a line across the outside of the belly. Stand the bridge in its (new) place and measure the string length. You can also measure the distance between the nut diagonally to the middle of the curve at the base of the neck. I have found that a comfortable neck-to-string length ratio is approximately 14 3/4" to 42" the puts the thumb opposite E flat. A shorter neck will oppose the thumb with D (or worse) and a longer neck will oppose E...... There is some wiggle room to move the bridge north or south without risk of harm. After that comes adjusting the sound post............