I have made three Double Bass Banjo's to date and there are two more on the way.

The idea came to me from my step-cousin Matthew Armstrong who was making a prototypical one which was superceded by one made by Peter Biffin (a maker of fine instruments -see links) who has apparently made some others too. Here are some pictures of Matt's he sent me.

It features holes cut in the skin for a soundhole and to accommodate the support for the bridge.

Peter Biffin's site spikefiddle.com shows this diagram of the design of the tarho (which is a similar solution to some electric-acoustic violins I have seen in music shops) where the pivoting of the bridge about a solid support under one of the bridge feet allows the second bridge foot to drive the membrane and it's cross-bracing.

 

The double bass banjo was first created around the turn of the century when the

banjo became very popular. All sizes were made from banjo-mandolin to bass-banjo

in order to create a banjo big band. The bridges rested directly on the skin creating

a dominant tone related to the distance between the rim and the bridge, which

colored the tone of all the notes with the corresponding frequency, especially up

high, making it undesirable musically, hence the rapid disappearance of the

instrument soon after. I have found a picture of a Leedy timpani bass produced in

1925.

Thanks to the web site, go visit it, I liked it.

Another approach I found whilst surfing the net is for a spring loaded counterbalancer behind the bridge as per what this

rather enterprising and clever man has done here at xstrange.com

 

The design I have used employs a grid work of cedar under the bridge which serves

to make the skin stiff in the middle and progressively floppier towards the edges

so as to make it behave something like a speaker cone with no dominant reson-

ances, this is the crucial element of the design for good tone and balance.

The tone is very similar to a double bass only the attack is a lot livelier and the

notes round out and fill out much quicker due the the lower soundboard mass which

also gives considerably better volume. Bassist's when playing pizzicato on a normal

double bass (as in jazz style) must accommodate by playing harder when they play

fast to get the sound to project as loud. On the bass banjo short notes have more

body and a faster attack which is ideal for pizzicato playing. The Double Bass Banjo

is not bowable (except for the A string), due to the lack of bouts .

 

The first one I called Birtha and she is based around a 22 inch Premier kick drum

made from rock maple and has a rock maple neck with a Honduran rosewood

fingerboard. She has been repainted, reconditioned and slightly modified and is

sounding in fine fettle.

Here is a photo of the grid work and drum (just painted and tuned up,) and the

neck and foot, and her triumphant in her resurrection standing by the new banjo

bass viol..Birtha is for sale with her eclectic sticker collection included.

 

The next one I made I called Fatima. She came about after a friend who played

double bass tried out Birtha and was most impressed and asked if I could make her

one.. I told her, "find a bass drum and I will make you one." Bass drums of quality,

on their own, are hard to find at a good price. She managed to wangle a 40 inch (!)

marching drum out of a local school where she teaches music and so it began.

The result was Fatima. The neck is from Blackwood (Acacia melanoxolyn,) the lattice is

spruce and cedar. The drum is birch which I stripped and sanded for a wood finish. She

is FAT! Bigger is definitely better for bass. The tone was much louder in the fundamental

and the higher harmonics are more complex, I suspect due to the more modes of vibration

possible with a large diameter skin. I am still searching for another 40" drum and waiting

for the promised photo and sound sample...

 

The next one is a Premier 18" floor tom with a Blackwood neck and has just been completed and is for sale and on display in The Bass Shop, Parramatta rd in Stanmore, Sydney. Thanks to Suzi and the lovely folks there for their support and advice, look no further for purchasing a Double Bass or getting repairs done, these people are the experts and very nice to deal with too. Playing their various antique basses (some 220 years old!) has been one of the highlights of my year so far, if you are a bass freak like me it is heaven. Al gifted me some old bridges to butcher to make the banjo basses and gave great advice on setups too. I only wished he could see this one now it is finished; it has a nice new batter and a surprisingly bassy sound wheras I thought it might not be as fat as the bigger drums but as this drum is deeper it probably does have a similar open air resonance although the bridge support goes further to the edge which probably helped too. It has a bit more punch as I suspected it would and very pleasing top end. Old time rockerbilly/hillbilly slap style playing yeilds a very pleasing thunky backbeat and so it is really well suited to that kind of playing. Hard to describe just how different it sounds so I better get around to making a recording and getting them up on the site soon.

These are the bits for the 24"so far; a stripped sanded and finished seventies Premier maple bass drum and the neck and foot from Blackwood with an Indian Rosewood tailpiece. I have prepared another 22 in birch and it's footpiece.

This is a photo of the 18 inch and the 24 side by side for comparison;

Here are the bits of the 34"so far; Premier vintage marching bass drum, Brazilian Rosewood tailpiece and New Guinea Rosewood with pacific Teak foot.