Soundposts and the like

[Gareth Hughes]

Here's a new newbie question some of you might be able to help with:

I have an Eminence Portable Upright Bass, which, in case you're wondering is an acoustic stick-bass so to speak. The portable part is the smaller body but also entails a removable neck.

So that this can be done often without the need of a new set-up each time the soundpost is held in place by a disc of wood at it's base, on the back of the instrument. I don't have a picture handy, but basically it would look like a candle on a flat plate.

My question is: why is something similar not done with regular upright basses? Is it because the 'disc' part would dampen some of the vibrations the soundpost is trying to spread out?

Thanks, Gareth

[Bob Branstetter]

Actually, many laminated double basses (i.e. Kays) and even some carved back basses do have a disk or platform like you describe. It is there to prevent the pressure of the soundpost from deforming the back and/or prevent a crack the the back. It is possible that the disk/platform may slightly dampen vibrations, but OTOH, some have speculated that the added mass could act as a form of "graduation" on a laminated back and improve the sound. In any event, the potential sound change is very small and if it prevents a crack in the back, it's good insurance.

[Gareth Hughes]

Thanks for that Bob.

I'm always curious when I see things like this that are outside the 'norm' and need to know why.

I think the 'disc' idea is a good one, if the benefits outweigh any negative sonic side effects. Especially for someone like myself who lives in fear of a sound post coming moving. It's not that mine looks or feels that it will, it's more the dread and hassle of having the instrument set up again as I don't know how to do it myself.

Fear really lives in the unknown

[Ken Smith]

Some roundback basses have a semi-center cross bar under the soundpost. My Bollbach bass has one and I had an Italian bass with one as well.

[Matthew Tucker]

"Held in place"??

Gareth are you saying the soundpost is FIXED to the disc? Usually the soundpost is just wedged in there lightly. The disc is not to stop the post from falling.

[Gareth Hughes]

I can't tell if the soundpost is glued in place, or if the disc has a hole in which the soundpost is inserted. Possibly the latter.

The body of this bass is only about three inches deep at best, so this measure is there as the bass is designed as a travel bass, with the strings/bridge being taken of regularly.