My Reed Tips are Too Open

A recent question about reed tip openings was posted on the IDRS mailing list. Jim complained that his reed openings were always too large and was looking for advice about correcting the problem. My response:

Dear Jim,

I've noticed most of the responses you've received on this topic have focused on the diameter of your tube cane and how the reed is scraped. While I agree that larger tube diameters and longer tie lengths will generally produce smaller openings, I think it is important to consider some other factors that affect one's reed openings.

The staple is an important variable which so far in this topic has been ignored. The shape of the staple's oval as well as its size both affect the reed's aperture. A smaller tube opening as well as a rounder oval will both increase the openings of your reeds. This is due to the fact that the sides of your shaped piece of cane have to deflect more from its normal shape as the piece of cane is bound to the staple.

Mis-tied blanks are often a source of large openings, not to mention blades standing apart at the top. If your piece of cane is not aligned correctly on the staple, (i.e. the edges of the blades in the plane of the line intersecting the focii of your staple's oval), then you effectively have a larger, more curved staple, again resulting in a large reed opening. It is virtually impossible to make a successful reed when it is not tied in correct alignment with the staple.

If your reed blank has a crack at the base of the reed, just above the thread, that will change the geometry of the reed blade making it more like the roof of a peaked house instead of an arch. The crack relieves the pressure of the curve tying the cane to the staple caused but allows the blade to rise as much as it can right at the crack, again causing your reed's opening to increase. It would probably be best to destroy these kinds of cracked blanks if they ever occur.

As for adjusting the opening by scraping off cane, I would recommend against it. In my experience, this only undermines the balance of the reed as well as the reed's overall playing qualities. I'd sooner take my pliers and flatten the oval of the staple a slight amount than scrape the heck out of the cane in order to reduce the reed's aperture. Ideally, you want the opening of your blank to be pretty similar to the kind of opening of your finished reed. That way, your scraping is concentrated on reed response, tone, dynamics and stability.

David Schast