bottoming out a string

[nonsqtr]

Hi all, I'm still having trouble understanding this issue. Is "bottoming out" a string during setup a good thing or not?

Here's the deal: once your action is adjusted the way you want it, you can tweak the angle of the saddle. At some point, you'll find a particular angle that causes the string to "bottom out". What that means is, it'll achieve a "deep resonance", it kind of sounds like some of the high end goes away, and the sound becomes deep instead of bright. This happens on every string type I've tried (Smiths, D'Addarios, LaBellas, DR's, etc).

The practical effect that I've noticed, is that the string tends to "vibrate more". It's almost like the amplitude of the vibration increases. That's why I'm thinking along the lines of a "resonance", although I'm not entirely sure about that. Sometimes this may cause some nut buzzing, but there's usually a string height that will mitigate that effect.

The key piece relates to the "consistency" of the sound across the strings. If you just do an ordinary setup, without tweaking the saddle angles, chances are good that some strings will be bottomed, and some won't. Basically that means each string will sound "a little different", some will be brighter than others.

What do y'all do about this? Anything? Do y'all typically adjust the saddle angles during setup, or not? And if so, do you "bottom out" the strings, or not?

 

[RiverFunk]

Interesting, the strings on most of my basses where often inconsistent sounding, I never thought about this adjustment!

Edit: Mm.. What angle of the saddle are you talking about? Can you please demonstrate? Thanks..

 

[nonsqtr]

The way the saddle sits on the bridge. Most saddles have two screws, one on each side, that adjust the height of the saddle relative to the base of the bridge. By raising one screw more than the other, you can adjust the angle of the saddle relative to the plane of the bridge.

 

[Figjam]

What angle does the saddle usually have to have to 'bottom out'?

 

[nonsqtr]

It varies per saddle. It's "empirical", you just have to find the right angle. However there always "is" one.

Sometimes the adjustment is pretty sensitive, and I haven't necessarily found any correlation between the string size and the sensitivity.

On some basses, when all the strings are bottomed out, the saddles end up sitting pretty straight, or roughly follow the curvature of the fingerboard. On other basses, the saddle angles end up being all over the map.

 

[RiverFunk]

I could get strange changes in the sound of strings in my bass with this adjustment, but the best sound was always on center (both screws equal). Changing from center seemed to weaken the low-end. And I couldn't bottom out any string. I think this is not for all basses. Some could benefit.

 

[nonsqtr]

I happens on all the basses I have with variable saddle angle (about a dozen). No counterexamples in my stable.

Agreed that for most saddles, the optimal point is "somewhere near the middle". There are definitely exceptions though. Some saddles need considerable tilt for the string to bottom out.

I've also noticed that this effect is frequency dependent. It definitely has to do with the vibration of the string. If you drop your tuning a semitone, the saddle will require a different angle.

Wow, I would have expected a bigger response to this thread. Seems that a lot of people aren't aware of this phenomenon.

 

[FaBu-]

Wow. I've never heard of that phenomenon. But I guess that I'd try to avoid this "bottoming out" as much as possible.

 

[carl-anton]

I never heard of this either. Could this be (one of) the reason(s) for dead strings? I'll try to fiddle with the angle next time I get a dead string, see if that's the problem. ...still not sure if I understand the phenomenon though.

 

[Bruce Lindfield]

...but I can't see any physics/logic behind it and I'm skeptical I'll notice any difference.

I agree - I have played around with this and more by accident a lot of times, my bridge saddles on various basses, have ended up being uneven and it didn't make any noticable difference to the sound - eventually, I "tidied them up", just as it looked neater when they were all even!!

I have a pre-Gibson Tobias though and the saddles there are a bit unusual and fit together as a unit, pressing against each other, so the angle does seem to have an effect - but it's a bit dificult to explain in words. But most, standard bridges it makes no difference as far as I could tell.

 

[carl-anton]

Could it be that since a plucked string also vibrate sidewards, this movement is affected by an angled saddle? (the higher side dampends the sidewards vibration whereas the lower side let the string vibrate more freely)

 

[RiverFunk]

I agree, I think it's a matter of the angle of string movement in relation to the angle of the surface that's restricting this movement. I've noticed changing from middle also affected the response of the string, like.. more or less attack which translated into more or less punch to the notes.. Which could be cool if the low end wasn't weakened.

There's only one angle at which I've found no low-end loss to occur (always middle). Maybe this is the "bottoming out"..