What exactly is the purpose for the resonators? Why do they go really low for low notes and then high in the middle then low again at the top for the black keys? This idea, I think, is more common in the older versions of marimbas, e.g. "Deagan" and "Musser". I notice that my old "Musser" 4 octave has the black key resonators the same depth on the high and low notes. Is this an astetic thing or acoustical thing? The newer marimbas, "Marimba One", "Malletech" do not look like the old Musser's, did they change the design? Thank-you for all the help and I hope I can clear up my confusion. Stan

Stan,

You are totally right it is an acoustical thing. I will give you the T.V. version of the explanation.

Basically when you play a bar without a resonator it will ring for a very long time, (taking in account that the bar is tuned properly and is not broken), however, the sound that is projected once the bar is struck is very thin especially in the middle octave plus you only hear the fundamental. When the resonators are added, the sound that is made upon striking is reflected up over the instrument and is 2 to 3 times as loud as a bar without resonators however the sound does not last for very long because as the sound that is reflected up cancels itself out. The beauty of the reflection is that now not only do you have a louder sound but also you get the fundamental plus the overtone series. This is especially demonstrated in the low octave of a 5 octave marimba and is usually a key factor in the sound a marimbist is looking for. If you go to the piano and play a chord and hold the keys down, the similar effect will happen.

To Ray's comments, I would add that each resonator is tuned to correspond to the bar above it - hence the larger resonators beneath the lower-pitched bars.

As to the length of resonators on the upper end of the instrument, the practice of using longer tubes for those resonators is purely aesthetical, giving a visual symmetry to the instrument when viewed from the audience; you'll notice that the resonators for the lower manual never go for this symmetrical design.

Look at the stops inside these sorts of resonators in the higher range of your instrument, and you'll see that the actual air column between the stop and the top of the resonator is smaller; the extended portion of the tube is purely there for visual purposes. Of course, that means that each set of resonators is that much heavier, each set requires more raw materials for construction, and also takes up that much more space when the instrument is broken down for storage and/or transport. That's why some manufacturers keep the actual length of resonators short on the high end of the instrument, and why some manufacturers don't have a full row of resonators beneath the upper manual, instead only setting resonators under the bars.

JW