Gapping for bending
Dear Winslow,
Is there a way to gap the reeds so they respond better to bending. I tried gapping my three hole reeds on my MB crossover in C but now it is actually harder to hold a bend on it than it was before I had messed with it. Do I want the reeds further away from the reedplates or closer to the reedplates? Or does it even matter? is it all in my head?
Thanks for your time!
Everything Mike says.
Draw 3 is the hardest to get right because it has the widest bending range.
Both the blow reed and the draw reed need to be able to cover most of he range of the bend.
In a dual-reed system, bending range is limited by the pitches of the blow and draw reed. But for the bend to work smoothly throughout that range, both reeds need to be able to bend independently through that range.
For instance, on Hole 3 of a C harp, the blow reed is G and the draw reed is B. The Draw B should bend down to slightly flat of G#, a semitone above the Blow G.
If you put your finger on the Blow 3 slot and play the Draw B reed in isolation, you should be able to bend it down to the G#, maybe farther. The bend may start to sound kind of weak at the bottom, but you should be able to get there without inordinate difficulty.
Likewise, if you put your finger on the Draw 3 reed, you can play the Blow 3 reed in isolation. If you play a draw bend on the isolated Blow 3 reed, it should start at G# and bend up to A with a nice strong sound. If it goes to the Bb, that's nice.
So how to do you gap to achieve these responses?
Well. the first thing to understand is that bending a note moves the center of motion of a reed. The wider its range of motion, the farther it can bend before it chokes out.
The draw reed in this bend pulls closer to the reedplate as you bend it down, so raising the gap helps widen the range.
The blow reed opens - moves away from the plate as you bend the pitch up from the initial opening pitch (G# in this case). So narrowing the gap will allow it to bend up farther - move farther away from the plate - before it stops responding.
That said, raising or lowering a gap too much can make response suffer - too wide and it gets leaky and unresponsive to soft playing. Too close and it chokes up under normal playing volumes.
I'm looking at the reedplates of a Filisko Marine Band in A that bends very nicely on Draw 3 - the note bends smoothly, is easy to sustain, and has a good, full tone at all bend depths.
If I look at the draw reeds, Draw 2 and 3 are both gapped wider than 1 or 4. No surprise here, as they are deeper bends. But viewed with the naked eye, the Draw 3 gap does not appear significantly wider that the Draw 2 gap. Both reeds curve gently upward from about the middle of the reed to the tip.
If I look at the blow reeds, the tip gaps on 1, 2, 3, and 4 are all WIDER that the gaps on the higher reeds, which seems counter-intuitive given what I just stated.
However, if I look along the length of the reed - again, this is all naked eye - Holes 1 and 4 have a very straight profile, rising seemingly straight from the rivet to the tip, and staying close to the reedplate along their length. Blow reeds in Holes 2 and 3, however, appear to be slightly elevated above the plate along their length, as compared with 1 and 4, and do curve upward, starting about halfway along their length.
As Mike says, finding reed adjustments that work for you is a matter of trial and error, but it helps to keep in mind the principles I mentioned, and to look at the profile along the entire length of the reed and not just the tip gap.
On the blow plate, a decent enough rule of thumb (could I be more vague?), is to gap as wide as the tip of the reed. On something like Winslow's A Filisko, the lower notes are weighted reeds with thicker tips. The higher reeds are not weighted and are thinner at the tip.
I can't remember off the top of my head when most 3 blow reeds are not weighted...by then, they won't bend as smoothly and easily as lower keys. Take an F for example. The technique used to play those notes is different.
My suggestions work for Hohner's, but Suzuki and Seydel harps, depending on the model, vary slightly. Winslow is a walking encyclopedia. I can tell you a lot about how to get something done, but not nearly the depth of why that he shares!!!
Wow, thanks to both you guys. I very much appreciate this so, My 3 hole is fine now, I guess I really did mess up the gapping on it. I found this information very helpful and interesting. thanks again
Trial and error...especialy 3 draw bend and the blow bends. Try gapping 3 blow really tight and then mess with 3 draw to find the sweet spot. The blow bends just need to be gapped tight and have good profiles.
The 3 draw, though, sometimes is tricky. Especially on C or higher. It will never be the same as, say, an A harp.