Measuring string compensation

Charting the 'sweet spots'

This is a simple routine that lets you come up with the exact location where you need to position the bridge. It also lets you determine whether you need a compensated bridge or not and if so, it tells you the exact amount of compensation you require for each of the strings. Also, if your bridge needs to be positioned on an angle this routine will tell you exactly what the angle is for your banjo. Read these instructions carefully but don't get intimidated, they are pretty easy to follow. In case you are not quite to sure about these instructions, take a trip to your local music store and ask them to show you how to set up the intonation on an electric guitar by adjusting the saddle bridges. Looking at the way this is done ought to give you plenty clues about what you'll be doing with your bridge. In case you're wondering, sure enough, that's where I got the idea for making my custom compensated bridges the way I do.

If, after going through steps, it turns out you need a compensated bridge then make sure you've settled on your favourite string gauges, bridge height, string spacing and neck angle before ordering a custom compensated bridge - any changes here and all bets are off and you need to re-measure.

Let's get started - chart the 'sweet spots' for each string starting with the first string, but before you do: be careful! Bridges are very brittle and can snap into several pieces that can come flying at your face real easily while you move them! You might be wise to slacken the tension of the strings first, especially with thin bridges, before you grab a hold of your bridge between your thumb and index fingers of BOTH hands.

To avoid any confusion, you're measuring the sweet spots of all strings relative to the first string so the "sweet spot" for the first string must be zero. One more thing defore you dig in: if your 5th string sits on top some kind of a slotted pip thingie behind the 5th fret (up in the air above the 5th fret instead of resting on the 5th fret itself) then there's no point in compensating it and you use a zero just like the first string.

  1. Position the bridge at a 90 degree angle to the third string (the normal, proper position)
  2. Move the bridge to where you can play a chime at the 12th fret (or 19th fret for greater accuracy)
  3. Now play the same note fretted, also at the 12th fret (or 19th fret for greater accuracy)
  4. If the pitch of the fretted note is higher, move the bridge towards tail piece (away from the neck). If you don't trust your ears to tell whether the pitch is higher, lower or the same, use an electronic tuner.
  5. Pitch lower? move the bridge away from tail piece (towards the neck)
  6. Mark the spot on the head where the pitch of the chime equals the pitch of the fretted note. Use a pencil or stickers to mark the spots.
  7. Repeat steps 2 through 6 for all strings - keep in mind, the fifth string's chime, or harmonic, is on the 17th fret instead of the 12th like the other strings.
  8. Draw a straight line (or use a sticky label or something) at the first string's zero point at a 90 degree angle to the 3rd string.
  9. Measure the distance from the zero line to the marks you've made for all strings

If your 'zero line' off-set measurements show zero for all strings - no matter what you've been told, you simply don't need a compensated bridge, period. Don't be surprised though if your results show something like this:

String Zero line off-set
#1 0 mm (always zero)
#2 2 mm
#3 4 mm
#4 3 mm
#5 0 mm

I know I'm repeating myself, but if seeing these kinds of measurements make you worry about the quality of your banjo: DON'T. Some banjos can easily reach 5 to 8 millimeter values, especially on the 3rd and 4th strings. I've seen top notch high-end models with big numbers on this kinda report card. I've also come across many "perfect zeroes" and in fact, many many many banjos simply do not need compensation. I've also seen some banjos with severe intonation problems where the biggest sweet spot number was only 4 millimeters. If you come up with number higher than 7 or 8 mm you better re-check the proper location for string 1 as something is likely to be out of whack. Either that, or you're probably using a bridge that's unusually tall or wide.Then again, you never know, maybe you got yerself a real heavy duty twister...

If the measured spots line up in a straight line, whether the bridge
 is angled or not, then you DO NOT need a compensated bridge.

I'm sure you've noticed, the measurements are all in millimeters. To me they're less confusing then them durned little and big and bigger stripes on the inch rulers (I've looked at them wrong stupid stripes once too often...). If you can measure only in inches, no problem - use a calculator. Even though the numbers are important, no problem rounding them off to the nearest millimeter although I can make to pretty precise.

Once you've done the measurements you know beyond the shadow of a doubt whether you do, or do not, need a compensated bridge for this particular banjo and for the way this particular banjo is set up. You'll also know the exact amount of compensation required, based on science and you no longer have to rely on anecdotal evidence, myths or "my buddy told me." There are a lot of enormously fantastic quality instruments around and, especially if your banjo belongs in that category, it deserves to get treated with the proper respect - go through this measuring routine and you'll know beyond the shadow of a doubt. If nothing else, you'll learn about the finer workings of your banjo. If it turns out you do need compensation you shouldn't be surprised at that, you'll now know exactly what to do about it. With this sweetspot routine there simply no longer is a reason to guess. What you're your aiming for is the ultimate sound and playability of YOUR banjo, not someone else's.

Important: many of the newer aftermarket bridges are a lot thicker than the way I make them. In fact, some of them are so thick that they end up changing the string length enough to affect intonation. Should you wish me to make a custom compensated bridge for you it would be best to first check the sweet spots with one of my straight, non-compensated, bridges to ensure proper compensation measurements or use a bridge with a top thickness of 3 mm maximum.

If you've used this routine to angle your bridge then keep in mind that string slots are very exact and tight on most modern bridges so angling often means the strings get choked off at either end of the slot resulting of course, in buzzing sounds.

Please note: I have come to feel pretty strongly that the only proper way to address intonation problems is to go it the custom compensated route. If a compensated bridge is not made according to the measurements done on your banjo then it's a generically compensated bridge based only on guesswork. Generic compensation simply cannot do the job custom compensation does and my own banjos deserve better than having to settle for "close enough," or "about this much." If you're thinking "yeah, but the second string's always out anyways" think again - this simply is no longer true. When perfection is doable, why settle for less. Perhaps overzealous, maybe not too smart marketing wise but as of November 2006 I no longer offer generically compensated bridges because, plain and simple, they don't cut it - how could anyone pretend to know by what and how your intonations are caused without ever having seen or touched your banjo?

There's two ways to get a compnsated bridge: take somebody's word for the "I know what I'm doing" about-this-much approach or the exact measurement solution. With the latter approach you'll never have to put up the word 'compromise' again. Think twice before deciding on generics.

If you'd like to order a bridge whether straight, or compensated, please go to this page to let me know the details. Your support is greatly appreciated.

previous page

next page

 
home picks contact us order guest book about banjo tabs links tell a friend our facebook
 
 
Copyright 2011 Bart Veerman
All rights reserved - No reproduction of these pages or the content therein without permission.