From Banjo Newsletter, 2003
I become quite distressed at times concerning the amount of mystery, confusion and downright misinformation that is commonly perpetuated regarding the adjustment, set up and mechanical function of the 5 string banjo.
In this article and the articles to follow in this series, I will present up to date and understandable explanations of how the banjo functions, and at times I will explain how you can become involved in, and sometimes in control of the the way your banjo sounds and plays. Through this series I hope to erase some of the "voo doo mentality" that surrounds the banjo and the way it works. The banjo is a musical instrument and functions under the laws of physics. We may not be able to produce banjos on the assembly line that all sound like pre war clones, but this is no reason to invoke the mystery of banjo witchcraft to answer what we cant control. A question with no answer is simply a point to be studied and understood after proper research is done.
To the other extreme, the use of formulas, technical measurements and pseudo scientific parameters is useless if the goal is to get the most out of your instrument. There is a place for science for sure, and I am a strong proponent of valid repeatable data. But you cant simplify the accurate set up of an acoustic instrument into a series of dialed in measurements and settings.
It is important to realize that YOU are the only person qualified to judge the sound of your banjo. My goal is to present valid explanations to you so that you have the information at your fingertips to execute some adjustments yourself, and have a clearer understanding of how the banjo works in general. It is mandatory to understand that each banjo has its own voice, its own strengths and limitations, just like the people playing them.
In this first installment, I want to offer you the chance to really "roll up your sleeves" and learn the single most important adjustment in the set up of the banjo. Adjusting the head tension , so that you feel it is the best it can possibly be.
The banjo head is the primary energy "amplifier" on the banjo. It receives this vibrating energy from the strings. Nothing has more effect on the banjos performance (positive or negative) than the tension of the head. It is of prime importance to have this part functioning at the optimum.
Whether you own an archtop, or flathead, whether you like the deep tubby sound of JD Crowe or the ringing crack of Doug Dillards banjo, the technique is the same. The tools required are a bracket wrench and your ears, that's all.
To save space, we will assume you are adjusting the head that is already on your banjo. But we will assume that it has no strings on it at this point. First check that the tension hoop is absolutely even all the way around the banjo. This is most important! If the tension hoop is uneven, no amount of careful adjusting will allow you to achieve a balanced tension on the head. And without even tension on all hooks you cannot achieve the optimum performance from your banjo. You need to either loosen the over tightened hooks or tighten the loose ones. Do this one at a time and keep at it until the metal band is within at least 1/32 inch of being even all around. Use a good ruler and measure from the surface of the head to the top of the stretcher band at all hook locations. How tall this measurement is, is of no concern . Sometimes after adjusting individual hooks in an effort to even the tension hoop it helps to push firmly on the head in a few spots to let the head tension even out uniformly.. It is especially true when backing the tension off the hooks.
Next, with your thumb, press down on the head at the point where the bridge is to be located. With reasonably firm pressure the head should not depress more than about 3mm . (this could be as much as 1/8" or slightly more). If the head sinks much more than that, tighten each hook by 1/4 turn of the wrench evenly all the way around. A head much looser than this will cause the bridge to sag in the middle and cause buzzes and the power will be severely limited. Adjust each hook in order at this point, NOT jumping from one side of the pot to the other. If you need to make it tighter still, go around the whole pot in order again, watching to turn the wrench 1/4 turn only. When you get the desired depression in the head, its time to string up your banjo, and slip on the resonator, tune and play. You are only checking the tone and volume at this point. Listen and remember. This is your first reference point. Make a mental note of the volume and tone characteristics.
Now, return to the hooks with your wrench . Again tighten only 1/4 turn each, all around the pot. Again tune up and play. And notice the difference, if any in volume and overall clarity of sound. What happened to the treble and bass response? Remember to occasionally check that your stretcher band is remaining flat in relation to the head surface.
Repeating this process you will easily begin to hear the tone and power changing ( likely improving at first). Keep repeating this process of 1/ 4 turns and checking. At some point you will notice that the sound didn't improve when you adjusted the hooks. It got worse. This could be in the nature of less bass, too much treble, or maybe the power seeming choked off, etc. This is your indication that the head has reached the maximum tension for that banjo, in its current state (present string gauge, tailpiece angle, bridge etc)
You just found the perfect adjustment for YOUR banjo! (actually, you just passed it). BACK off all the hooks by 1/4 turn to the last adjustment that showed improvement and you are DONE. Let the banjo stabilize for a day or two. Playing it will help settle things in place. You can stabilize things quickly by firmly pushing on the head with your fingers all over to flex out the last undesired adjustment, and your head is there.
This is the time to get out your torque wrench if you have one. Check the inch pound measurement you have reached and insure that all 24 hooks are the same. Write this information down for future reference. Now when you change the head on THAT banjo, you can easily reproduce that sound. But ONLY if using the same style head, strings, and identical set up. This is also the time to check what note your head is now tuned to if that is important to you. Again for future reference.
If you have 5 banjos you need to do this whole process on each banjo, even if they are all Gibson Mastertones, they all will need individual attention given to the head tension. Remember our goal is to find the optimum sound for "that" banjo. There is no reason to assume any two banjos will sound the best at the same tension without listening to the way each banjo plays and sounds.
I hear people asking the "note" to which someone tunes their head to. So that they can copy this setting in an attempt to get the same sound as their favorite banjo hero. I hope you will accept the fact that this is a fruitless effort. There is SO much more involved that the copying of this one point will almost assuredly gain you nothing in improvement and may even be detrimental to your specific banjo set up. We will address these other points in future efforts.
As a final message, may I reinforce the idea that if the sound of your banjo is an important point for you, shouldn't you be concentrating on "listening", instead of searching a list of generic points to force your banjo to submit to. The rewards are guaranteed for those choosing to listen.
I hope you can take some time in the next few days to try this technique out on your favorite banjo. I know it will be a learning experience for you.
Scott Zimmerman - 9-9-03