Banjo Bridges by Bart

Volume Chart

I got busy with my soundlevel meter one afternoon to get an idea how a bunch of different bridges I had made would behave. I took the readings in my living room, not in any kind of acoustic lab room or anything like it, so I had to figure a way I did them all the same to make sure I would come up with [hopefully] unbiased numbers. Keep in mind also, the numbers are all relative: they are as they applied *that* afternoon to *my* fingers playing *my* banjos. Here's what I did:

1) Digital sound level meter set for A Scale weighting, Fast sampling, all numbers in dBA

2) "Facing" sound volume - the meter pointed directly at the banjo at a 1 meter (=3 ft + 1 beer) distance

3) "Away" sound volume - the meter pointed away from the banjo into a large open concept kitchen, also @ 1 meter. This measurement is really the most important number as it determines how a banjo's sound will project/carry and this is how your audience hears your banjo, check the last table on this page to see what I mean

4) "B2E" = banjo-to-ear distance. The meter pointed horizontally towards the player's ear, 50 cm (about 20") away from the center of the banjo's head. It should really have been 40 cm but the tripod the meter was mounted on didn't want to get that close to my chair. The point of this exersize was to show how many decibels the banjo shoots directly into the player's ears.

5) Peaks and Averages measured over a 60 second period (includes grab-the-banjo and push the start button time)

6) Wearing finger picks while playing 3 finger style down the neck, up the neck (both X and Y positions), digging into the strings pretty good as if playing a break

7) Patient 1: Fender Leo, equiped with light gauge strings, ugly see-thru clear head - decent banjo, decent volume

8) Patient 2: Framus Nashville, fyberskin head, medium gauge strings, (heavy gauge 4th string), Saga neck - lower end of the scale in the banjo world, tends to get drowned out in jam sessions (although a bit of tinkering will make a huge difference...)

9) Patient 3: Ode D, thin head, light gauge strings - kick-butt top of the line banjo

10) Patient 4: Stelling Bellflower, light gauge strings, a powerhouse banjo

Here's the "map" for the bridges

X E A 3
description
X      
bridge wood
X = mystery, J = enigma,
T = teak. W=walnut, M=maple 
  E    
topping wood
E = ebony top
X= different mystery
_ = no topping
    A  
A = regular weight
B = medium (heavier) weight
      3
2, 3 or whatever number of legs

Fender Leo - dBA

Wood

Peak
Facing
Average
Facing
Peak
Away
Average
Away
Peak
B2E
Average
B2E
XXA3 94 83 89 80 97 84
XXB2 95 83 90 80 96 87
JXB3 93 82 90 80 98 87
TEB3 93 80 89 79 96 85
X-B2 93 83 91 80 96 85
X-A3 92 81 91 80 96 85
XEA3 94 82 92 79 99 87
TXA3 93 82 89 79 95 85
XEC3 93 81 90 80 96 85
JEB3 93 81 90 80 96 86
no-frill Grover 88 79 86 76 92 83

Framus Nashville - dBA

Wood

Peak
Facing
Average
Facing
Peak
Away
Average
Away
Peak
B2E
Average
B2E
XXA3 94 82 89 80 95 84
XXB2 93 82 90 80 97 84
JXB3 93 84 90 80 96 85
TEB3 94 83 91 81 96 86
X-B2 92 83 90 80 98 85
X-A3 95 83 91 81 97 87
XEA3 93 82 92 81 97 86
TXA3 93 81 90 79 95 84
XEC3 95 83 89 79 95 84
JEB3 94 82 93 79 93 82
no-frill Grover 93 81 87 77 92 80

The numbers for this Framus increased dramatically after I installed a custom hardwood rim in it, it now sounds every bit as loud & proud as any decent mastertone/clone banjo.

Ode, Model D - dBA

Wood

Peak
Facing
Average
Facing
Peak
Away
Average
Away
Peak
B2E
Average
B2E
XXA3 97 85 92 82 96 86
XXB2 94 84 92 82 97 88
JXB3 94 84 90 81 98 88
TEB3 95 84 92 81 97 88
X-B2 95 83 92 81 96 86
X-A3 93 82 91 81 97 87
XEA3 94 83 91 81 97 87
TXA3 93 83 91 80 94 84
XEC3 92 81 88 79 93 84
JEB3 93 83 91 80 97 86
no-frill Grover 90 81 87 79 92 82

Stelling Bellflower

Wood

Peak
Facing
Average
Facing
Peak
Away
Average
Away
Peak
B2E
Average
B2E

JEA3

96

88

93

83

99

88

JYA3

96

87

93

84

97

90

TEA3

98

87

95

85

98

90

TXA3

96

85

92

82

99

89

XXA3

96

86

93

83

97

89

XEA3

95

85

92

84

98

89

XXB3

97

85

92

83

98

89

XYA3

96

85

94

84

98

88

XEa3

97

86

94

84

97

89

It's hard to come up with any kind of interpretation of these numbers except that a change up/down of 3 dBA means twice or half the volume. The Stelling banjo won the overall decibel race but it was very close volume wise, to the Ode as most banjos of this caliber would be. A couple of things are clear though: you can improve on volume by choosing something other than a no-frill standard bridge that comes with most banjos. In particular, the way the sound carries at a jam distance is of great of interest. The charts also show that bridges produce different volume levels on different banjos. Keep in mind too that these charts only show volume, not tone. In fact, louder does not automatically mean better tone although the more volume available, the more tone and dynamics you have available to exploit as a musician. My personal overall favourite for tone and clarity was the XEA3. Well, that afternoon anyways...

Just to be sure: these numbers cannot be compared to any other numbers unless they are measured during the same picking session, using the same banjo(s) played by the same musician else you'll come up with incorrect and/or unfair numbers.

In case you're concerned about your hearing and the high number of decibels some banjos produce - put your banjo down for a minute and click here.

"Away" volume continued

This afternoon (Feb 2005) I stumbled across the perfect example to illustrate the importance of the "away" volume. Someone brought a Gibson RB-3 to see if I could squeeze out some more horse power. It was a marvelous instrument and everything was set up real nice and tight. The banjo was totally responsive and sounding great, it was equiped with an excellent after-market bridge (0.656" or 21/32" height). I picked my way through a handful of different bridges and the mystery topped teak bridge (5/8" - yup, that's lower than the original bridge) put this banjo right in the magic zone - totally crisp and clear all the way up and down the neck with perfect intonation. The sound level meter showed identical volume levels for both the original bridge and this new one. Yet, the teak/mystery jobbie made this banjo sound decidedly "bigger," the banjo barked big time. Spinning the meter around, having it point away from the banjo clearly illustrated why and how:

RB-3

Peak
Facing
Average
Facing
Peak
Away
Average
Away
Peak
B2E
Average
B2E
original bridge - 0.656" 96 84 90 81 96 85
Bart TXA3 - 5/8" 96 84 95 83 97 87

Like I said, the "away" volume level is hugely important as it is shows how well a banjo projects its sound - the way your audience hears it. In this case the the "away" volume was only 1 dBA less (for both peak & average) than the "facing" volume. Yup, this RB-3 rocked!

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Copyright 2009 Bart Veerman
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