Our recent epiphany into the many benefits of a mandolin armrest (we are so sold on these!) brought us to the topic of wood vibration. The concept of a resonant back and top needs some clarification if one is to understand how best to not inhibit the natural reverberation of the body.

Best to examine a drum head. If you haven't had this experience yourself, the next time you have the opportunity to tap on a drum (timpani, conga, snare or tom, as smaller bongo won't be as obvious), listen how the sound is different from striking the center as it is to the edge. Actually off-center is more appropriate, as directly in the middle is another nodal dead spot.

Midway between center and edge, there is a richness, a range of "sweet spot" you lose the closer you move taping toward the edge of the drum. You start losing the lower harmonics, let alone volume. This is not unlike what happens on the back of your mandolin. So what you have to keep in mind is the closer to the sides of the instrument your abdomen touches, the least amount of physical interference.

You can achieve this with a wider angled position (touching only the edge), but of course, the instrument has to still rest securely and comfortably as you play. A tone-gard can be miraculous here, but even the minor posture shift can go miles to letting a resonant back sing. The point here is if you are touching the back near the sides, the muting is not all that detrimental.

This brings up the issue of armrests. Concern about dampening is completely unfounded, as these pretty much attach to the sides of the mandolin--very little contact with the top. This plus the benefit of lifting your arm up higher with little to no top interference makes them almost a must-have.

Read about the McClung Armrest.

Posted by Ted at July 17, 2008 1:55 PM