At 05:36 PM 4/6/97 -0400, you wrote: >Since I've read the first post on this subject, I've been wondering. If the >small indentation the string makes in the bridge can reduce sustain, is it= a >good thing to tap strings on the bridge to get rid of false beats? It seems >to me that by tapping the strings, we would be driving the strings in the >bridge. Would it be better just to tap the bridge pin? Also, is it the >sanding that improves the sustain or could it be only the renotching? > >I'm curious to find out what you all think. > >Marcel Carey, RPT >Sherbrooke, QC > NOTICE: The following is my OPINION (based on experience and logic), not to= be confused with, and modifyable ONLY by, FACT (or gooder logic). Hi Marcel,=20 If the grooves are deep, the string termination point will be farther= forward on the bridge than on the bridge pin. That could affect sustain.= Other that, I don't see how.=20 As far as tapping strings on the bridge, I think it's not a good practice. I= have heard and read many times that strings will ride up on bridge pins and= need to be "seated" to stop false beats. This is contrary to the laws of= physics as I know them. I don't think it's possible for a string, with= measurable positive bearing, to ride up a pin (against tension), slanted to= force the string down on the bridge (against side bearing), and stay there= until someone knocks it back down where it belongs. It's just a case of= techs misinterpreting what they think they see and hear. The string noise= most likely comes from a loose bridge pin. Isolate a beating string with= mutes, play the note, and press a screwdriver against the front bridge pin= on the side opposite where the string touches. The beat will probably go= away, returning when you remove the pressure. Tapping the string down will= temporarily clear the beat up by wedging the string down into the groove in= the bridge, making it deeper in the process, as it springs the loose bridge= pin back against the side of the hole until the movement stops, further= elongating the top of the hole. The noise stops and the assumption is that= we have seated the string back down on the bridge where it belongs, when= all we've done is affected a temporary "false positive" result at the cost= of long term damage to the=20bridge. The problem will be back with the next= humidity cycle. Driving the bridge pin deeper is a much better approach,= (gently) but won't work in many cases. The real problem is the loose bridge= pin and can be cleared up by epoxying (or CA) them in solidly. This isn't a= casual field repair to be done with a normal tuning. It requires lowering= tension, disengaging strings from the bridges, epoxying, curing,= re-assembly, and tuning. It's time consuming, expensive, and traumatic to= most folks. That's why most techs continue to take the easy out and "seat"= the strings as they shorten the long term service life of the instrument.= Sometimes you don't have a choice in a concert situation where you have to= make it clean, and right now. Just remember to consider seating strings on= bridges to be an emergency only procedure, not a daily practice. To all: If anyone has contrary enlightenment, I'd be pleased to hear it.= Rants will be deleted immediately. End of opinion. Ron Nossaman
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