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I've read conflicting info on fitting of saddle for undersaddle pickup. Should the saddle be a bit loose so that it vibrates more or should the fit be tight in the slot?

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Rich Smith
Issaquah, WA

Tight in the slot. I've never heard of anyone wanting a rattling saddle.

If you can turn the guitar over and the saddle falls out it's to loose. Make it just tight enough so it won't fall out of the slot. Use your calipers to measure the slot width, get the saddle close all the way from end to end and just fine tune the saddle thickness till it fits nice and snug.

It's also vital that the saddle bottom be flat and that the saddle slot in the bridge be flat too. You'll have issues with picking up the string vibration if the saddle does not contact the bottom of the slot fully along the length.

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the saddle should always be tight. The tension of the strings will pull it over if it is loose. not so tight that you cant remove it, but a good snug fit.

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Ken H

Reasonably tight, but not so tight that it can't seat properly on the pickup. Try waxing the saddle to make it slip easier and seat. If you're building guitars from scratch, then cut a tilted back saddle slot so you get better down pressure. I go about 7 to 8 degrees back tilt.

So I gather that vibrations from the strings is transmitted through the saddle, and not that the strings have to move the saddle? Guess I read some bad info suggesting the latter. Thanks all.

_________________
A higher purpose for wood.
Rich Smith
Issaquah, WA

A UST pickup responds to the pressure differences caused mostly by the vertical pressure waves coming through the saddle to the top of the pickup compared to the bottom of the saddle slot. Pickups actually intercept the string vibrations before the guitar top gets them...one of the reasons for the particular sound of UST pickups. You really want the input to the top of the pickup to be as isolated from the rest of the bridge as possible...which isn't possible if the saddle fits too tight in the slot.

There's a point where you just can't have it both ways...acoustic perfection and electric optimization are slightly incompatible.

With a saddle transducer I fit saddles loose, through that may mean different things to different people. What I call a loose saddle is one that if you have the strings off and turn the guitar upside down it probably won't fall out, but you can still lift it out with your fingers. What I call a tight saddle would have to be removed with a set of pullers. I do find that saddle fit too tightly can often be pinched more in some areas of it's length and give problems with even response.

Different meanings of tight and loose to different folks, but I think most are talking about the same fit. What constitutes the difference to me between a properly fit tight saddle, and a properly fit loose saddle, probably comes to less that a half thousandth inch difference in thickness. Having a saddle that easily falls out or actually rocks is what I would call way too loose.

In thinking of how it works, the pickup need not actually move up and down within the slot, but it does transmit waves. If it it pinched off too tightly by the bridge, these waves don't transfer down through the pickup as well. Good examples might be with a modern Martin saddle. They are usually fit quite well, but can often be just a tiny bit too long for the slot and tight at the ends. When installing a pickup this can sometimes choke off the output of one or both of the outer strings, so I always take just a few swipes at the ends to loosen them up.


Edit: - Rick beat me to it. Pressure is a key word to help understand how it works. A change in pressure does not necessarily require a change in position, but if the saddle is clamped too tightly by the sides then the pickup at the bottom may never feel the change in pressure (or at least feel less of it).

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I think I may have my saddle too tight. I notice that when I tap on the treble end of the saddle the pickup sound is much louder than the bass end. I've been careful to have a flat slot and a flat saddle, but I have to push down quite hard to seat the saddle. I'll sand it a bit to see if I get better, more consistent sound. Thanks.

_________________
A higher purpose for wood.
Rich Smith
Issaquah, WA