Banjo bridge volume chart shows surprising decibel levels

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!

Banjo Bridges by Bart