The bridge must be made of a hard wood, usually maple with an ebony top edge. Plastic inserts in the bridge will cause tone loss. Bone or pearl inserts in the bridge will also change the tone. Tenor banjo bridges have two legs sitting on the head. Five string banjos bridges should have three legs to distribute the sound evenly to the head. On the top edge of a bridge, the ebony should only be about one-sixteenth of an inch thick to allow maximum sound. Bridges may be sanded thinner and the corners rounded. If there is too much wood in the bridge, it will absorb more of the vibration energy produced by the strings. Some bridges are curved or cut with zig-zags on the top to compensate for accuracy of tuning.
The resonator reflects the sound from the back of the banjo to the front. Banjos without a resonator do not project as clear a sound. The inside of the resonator should be as smooth and shiny as possible to reflect the sound outward. The air gap between the bottom of the rim and the resonator should be at least one-half an inch clearance to allow the air resonance inside the banjo to project outward. If the air gap is too small, the banjo will seem muffled.
The string nut at the top of the neck should be made of bone or a synthetic bone for best sound. A soft plastic nut will cause tone loss. Other materials such as pearl, brass, steel, or hardwood. produce different tones.