Quinto/Conga/Tumba belly measurements

[Roka]

Hi all,

My turn to craft something now
I have got a few nice and fat trunks of Ash wood and I will carve
a solid shells, but I've got some questions regarding measurements.
Is there any mathematical top/belly/bottom diameters proportion ?
It's clear about the top - 11, 11,75 and 12,5 as I will use the standard HW,
but belly... It seems there are few variations and I don't have so much expensive
(at least in my country) wood to begin experiments.
Have you any suggestions regardin quinto/conga/tumba belly diameters ?

[jorge]

You might start by copying the shape developed and popularized by Vergara and copied by Junior Tirado, Skin on Skin, and other conga makers. Or just find some drums that sound great to your ear and try to copy them. Trial and error is a long, labor intensive and expensive process in conga making. The mathematical acoustics of conga sound are complicated beyond current theory, software and measurement technology, so culture, listening, observing and copying are the way to go.

[JohnnyConga]

When I registered an invention of mine with the united states patent office for Conga drums a (Sound Reducer) I found out that there are actually 59 patents on the Conga drum...when you do research on the Conga drum you can find everything there is to know about the Conga drum including size, shape, etc...just go online to the United States Patent Office and research the Conga drum...it's actually amazing stuff...including Marlon Brandos 'conga tuning invention for the Conga drum...

[jorge]

Did Patato really invent and patent tuning lugs for congas? If so, I wonder what percent royalties he got from the companies that use metal tuning lugs. In fact, I doubt ANY of the money from those 59 conga patents ever made it to the hundreds or thousands of inventors in Congo, Nigeria, Cameroon, Cuba, Brazil, Puerto Rico, Guinea, Senegal, Mali and other places over many centuries who innovated and invented the various drum shapes, tuning systems, skin configurations and processing methods, stave construction methods, log hollowing techniques, cajon styles and construction, reinforcement bands and almas, etc. Some of these inventions and innovations were made centuries before even the Efi / Efo claims of stealing secrets, and I am sure many worthwhile innovations were forgotten or lost and reinvented more than once. So I say when it comes to a pretty intangible and cultural thing like shape and size of the belly of a drum, copy away.

[Jerry Bembe]

The size of the belly depends on your personal taste in tonal qualities. The following comments are from my personal experience and correspondence.

There are basically 2 shapes traditional (barrel shape) and contemporary (Valje style). They are both good but deliver different tonal characteristics.

The traditional shape will favor the mid-range to higher frequencies while the contemporary shape will favor the bass frequencies. The contemporary shape can do this because it is fatter in the belly due to its angular shape opposed to the traditional curved shape.

I have found that a 11 3/4" contemporary conga with a calf head to have a fuller and lower bass tone than a 13" & 14" traditional congas!

I have heard that VGA percussion (Lou Vega) makes their contemporary congas approximately 1" wider in the belly than Valje. This would allow for amazing bass response if this is your taste in sound.

It all comes down to what is your personal taste.

[pcastag]

A lot of the bass tones come from the narrowness of the bottom, this is a purely physical property explained by musical acoustics, the bass waves are long and have a very high amplitude, when they are forced through a narrow opening they expand on the other side creating a very pronounced bass sound. My sonocs don't have a particularly large belly but have a rather focused bass responce when lifted due to the small opening, toca traditionals have the same effect.
PC

PS you can really see this on a djembe or doumbec where the small conical shape forces the bass notes out.