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View Full Version : violin-style sound post on a ukulele?



theabsurdman
01-24-2015, 01:15 PM
I restored a 1950s plastic ukulele recently and was surprised to discover a violin style sound post positioned under the bridge connecting the sound board with the back. Is this unusual? And if so, why are they generally found on violins but not ukes? Has anybody found that putting one in improves resonance etc.?

Ron B
01-24-2015, 01:37 PM
I wonder whether the post might have been structural rather than meant for sound improvement.

PhilUSAFRet
01-24-2015, 02:36 PM
:agree:.................

BlackBearUkes
01-24-2015, 03:39 PM
Violins are bowed instruments, ukes are plucked instuments. If you add a sound post to a uke, the back is now part of the sound producing structure rather than a reflective plate. Adding a sound post also kills the sustain. Pluck a violin and the sound decays almost instantly, which it should. The sustain on a violin is produced from the bow sliding on the strings.

Who ever added the sound post to the plastic uke was probably experimenting and just forgot it was there. A plastic uke under string pressure should pull the top up, negating any reason for a sound post at all.


I restored a 1950s plastic ukulele recently and was surprised to discover a violin style sound post positioned under the bridge connecting the sound board with the back. Is this unusual? And if so, why are they generally found on violins but not ukes? Has anybody found that putting one in improves resonance etc.?

Chih-Wei Liu
01-24-2015, 04:09 PM
If the back is super rigid like the laminated Smallman-style back , a sound post don't kill much sustain, but still turns a loud instrument into a quiet one. A bridge doctor is like a much heavier sound post with the other end registered on the tailblock.

OregonJim
01-24-2015, 04:57 PM
Soundposts are only used in instruments with arched tops and arched backs. They are used to transmit string vibrations from the bridge to the back, and to provide structural support. Placement is critical - even a fraction of a millimeter movement can adversely affect the tone and volume. Most instruments with a soundpost are bowed, though not all - there are archtop guitars and mandolins with soundposts as well.

DennisK
01-25-2015, 10:53 AM
The soundpost is a fulcrum. The downward pressure of a bow on a string prevents it from vibrating much in the up and down direction, but by anchoring one foot of the bridge against the back, the side-to-side vibration causes the other foot to pump up and down on the soundboard. Plucked instruments don't need it because the string and the whole bridge/soundboard are free to vibrate in the up and down direction.