Dugafola wrote:do your duns have a little hole in the middle?
Dugafola wrote:i'm not convinced they improve sound at all either. but they may help in making your skins last longer.
michi wrote:Thinking about this some more, I know that my dunduns go up in pitch quite noticeably on a hot day.
But that's not caused by increased pressure inside the drums or by a change in the speed of sound. Rather, as the shell and rings warm up, they expand, so they have a larger diameter. At the same time, the increase in temperature drives moisture out of the skin, causing it to shrink.
The two effects combine to increase the tension of the skin, so the skin's resonant frequency goes up.
Trumpet wrote:Funny you should mention that. This morning we had a concert and it was easily the hottest day we've had all year (91 degrees), yet this was the lowest the Dun sounded. Go figure.
Rhythm House Drums wrote:I also was thinking this would help release the pressure and let the top head vibrate more freely since the bottom head was restricted. So.. even with two 2" holes, not a lot of difference.
Where I do notice some audible difference is when I turn that drum on it's side and play it traditional (looks funny playing a 32" drums sideways). I almost hear an echo like I hear one head hit and then the other says me too!! .. but slightly off... covering the ports takes this delay away.
Michi, you said that the dunun raise in pitch on a hot day. I've noticed the same. Actually coming back from festival, and most recently DrumStrong where the dunun stayed out all night, they went from in tune, (morning) to a little high when it started to get warm to way low and almost floppy when the dew set in about 2am or so. Then the next day around 2pm it was 80 some deg. F. and the drums were tighter than ever... so Temp and humidity definitely change the pitch.
But I was always under the impression that it was the skin that would tighten and loosen. It seems that the skin would flex and be more dynamic than the rings or the shell. I can see the shell and rings expanding slightly over several days, but to change so much in such a short time.. I always blame the skin.
The rings will expand instantaneously as they warm up. Ever seen images of buckled railway lines in summer? I haven't looked up the expansion coefficient of steel and worked out how much bigger the rings will get with, say, a 15°C temperature change. I wouldn't be surprised though to learn that it might be as much as 2-3 mm.
Users browsing this forum: No registered users and 1 guest
Translate this page using Google