Why Does a Banjo Sound Like a Banjo?

This seems like a simple question, right? But as I have the privilege of talking to so many of you on the phone and via email, it has occurred to me that we have not offered you a simple answer to this question. We have told you about rims, heads, tone rings, etc. but a simple “what is happening” explanation about the mechanics of what is going on when you play has not been offered. Let’s see if I can break it down for you in a simpler “1-2-3” order so you can understand what is going on.

When we hear a choir singing, we love the beautifully blended sound that we hear. Each member of that chorus is unique, no one member sounds exactly like the other member.

But when the conductor coordinates their efforts and blends their natural gifts, the resulting sound is harmonious and pleasing to the audience.

The parts of a banjo are like a chorus. At Deering, we give special attention to the natural material that each part is made of and we “balance” or adjust their set up so that the resulting sound is beautiful and harmonious. Not everyone wants to hear the same sound out of their banjo that is why we have a multitude of variations we can offer so that the resulting musical tone is the one you want to hear. But, the basic mechanics of what is going on is consistent. It is this basic mechanics that I want to address today. 

Playing a banjo is like an exercise in physics. By definition, physics is the science of matter and energy and the interactions between the two. From this we can see how this fits naturally into what we are doing when we play a banjo. We will be walking through the pathway that the vibration passes to give us the resulting sound that we hear when we play. By understanding this pathway, we can better see how not only what the parts are made of but how they are “balanced” together that gives us the sound we want to hear.

1. When you strum the strings of a banjo, you are the source of the “energy” that makes the banjo strings vibrate.
2. The strings are connected to both the neck and the bridge. That vibrational energy is passed on to the neck of the banjo and down to the bridge of the banjo.
3. The neck will vibrate and because it is connected to the rim, then it will also cause the rim to vibrate.
4. The strings are touching the bridge so they pass their energy on to the banjo head.  Notice that the strings do not physically touch the banjo head.
5. It is the vibration of the bridge that causes the banjo head to vibrate.
6. The banjo head is touching the rest of the pot assembly (rim and/or tone ring) and the energy now transfers from the bridge to the tone ring and/or rim which will now begin to vibrate.
7. On a resonator banjo, the sound that is caused by everything now vibrating at its own natural sound, is reflected off the back and sides of the resonator and pushed forward resulting in an increased volume.
8. If we had an openback banjo, the resulting sound would dissipate out of the back of the rim to be absorbed by our body and/or go out and fill the room.

By looking at the pathway, we can understand how the materials themselves can regulate the sound we hear out of the banjo.

1. Hardness of the neck wood will regulate how much energy is passed on to the other parts that it comes into contact with. Maple, because it is a stiffer wood, absorbs less of the energy from the strings and thus passes more of it on to the bridge. This increased energy allows the pot assembly to vibrate with more activity and thus give you a brighter tone.
2. The string gauges are important. Lighter gauge strings require less energy to stimulate. Thus using lighter gauge strings will give you a brighter sound because they vibrate with a greater energy which reaches the bridge and thus passes on, again, to the pot assembly.
3. The pressure on the strings from the tailpiece can also  regulate the vibration. With more front edge pressure on the strings, they will vibrate less freely; sharpening up the tone of the banjo. This is why an adjustable tailpiece is a friend to the banjo player.
4. Maple, as we have already noted, passes on the energy and absorbs less because it is a hard wood. That is why maple bridges make your banjo “sing” better…more energy is transferred to your banjo head and on to the pot assembly.
5. The thickness of the banjo head will regulate how much energy gets to the pot assembly.  The thicker the head membrane, the less it will vibrate. The less it vibrates, the less energy it can transfer to the pot assembly resulting in a warmer tone.
6. Head tension does much the same as the thickness. The stiffer the head tension, the more treble you will have. The softer, more bass. It all has to do with how much the head is vibrating and how much energy is passed on to your pot assembly.
7. The type of tone ring material and how much of the tone ring is in contact with the head changes the sound. At Deering, our -06- tone ring has a rounded edge so that more of the tone ring touches the head thus it able to get more energy from this direct contact. And the resulting sound will be more vibrant as the bell bronze rings with greater energy.
8. The rim wood must be able to allow the parts connected to it to vibrate and not stifle the energy transference. This is one of the chief reasons our new violin grade maple rims have improved the overall sound of all our banjos. They have given the pot assembly more freedom to “ring and sing.”

When one of our customers asks me how he can make his banjo sound a certain way, it is important to know that not just one component is involved in making the sound one hears from his/her banjo. The ability to adjust the setup of the banjo, the freedom to tweak the components, is one of the reasons we call the banjo the “hot rod” of acoustic instruments.

I hope this article helps you all have more fun with your own “hot rod.”