Replies

1. 
   padook | Nov 27, 2006 01:03am | #1

   Yours may be a different species but the macacauba that I've tried (Platymiscium yuccatanum) is very good for marimba bars. Other Platymisciums that I've tried, Granadillo (P. pinnatum) and Hormigo (P. dimorphandrum) are also very good.

1. 
   Jimma | Nov 27, 2006 02:52am | #2

   Mine was rosewood.

2. 
   DavidCarlson | Jan 07, 2007 08:18am | #3

   Brazilian Rosewood, Hormigo, and Paduak are the types that I have heard of using for the Marimba. I have some information on that project, if you'd like. I found the formulas for the pipe dimensions, the tuning, etc. It was an interesting project for me, until it talked about taking hours to tune ONE bar. Twelve bars in an octave make for a long time tuning... Not to mention mistakes.

   To those who are interested, I figured I'd post this info that I've compiled so far...

   To calculate the length of the tube:
   L = v/f/4 (closed end tube)
   v=speed of sound in FPS (1129fps@70 deg F, 1132 at 72, and 1146 at 85)
   f=Frequency in Hz (A4 = 440, A#4 = 440*1.059463, and so on...)
   4=1/4 wavelength factor

   Calculating distance between the bar and tube:
   D=0.61r, where r is the radius of the tube in inches
   Placing the bar closer will increase sound, but flatten the note.

   Suspension points are spaced 1/5 of the length of the bar from the ends

   Removing material from the middle of the bar will lower the fundamental note, remembering to carve it in a circular pattern. Divide the carve into 4 sections, starting at the midpoint of the curves near the end.

   | 1 | 2 | 3 | 4 |

   Decreasing the radius of the curve at the ends (Removing material almost near the ends of the carved portion near where 1 and 4 are) will tune the 2nd harmonic, which should be +1 octave. When using a closed end tube, these will be dead, so don't bother tuning. The 3rd harmonic is tuned by carving where 2 and 3 are, tuned to +2 octaves. The 4th harmonic is rarely tuned due to it's very short sustain, but can be tuned by flattening close to the centerpoint, which should tune at +2 Maj 3rd. Only really try this on your lower bars. On closed tubes, the even numbered harmonics will not show through the sound.

   To hit the bar for pitch, grab with your fingers near the suspension points, and strike the middle. For the 3rd harmonic, grab slightly up from center, and strike slightly up from the lower suspension point. The 2nd harmonic lasts for 1/2 the time of the original pitch, while the 3rd lasts 1/7 as long. Imagine where the 4th harm is. That is why it's rarely tuned.

   Hope it helps. I can be e-mailed at [email protected]. Sorry, but I don'thave any dimensions for the bars.