I have a great B reed…almost. What Causes a reed to raise it’s pitch under pressure? The A and E are the suspicous characters in this scenario
I’m not answering this as a reed expert, but assuming that you are keeping to the school of referring to notes on your B chanter in-line with the concert-pitch notes, I offer the following:
I have little experience with flat-pitch chanters, but I have found that a concert pitch chanter will produce a pressure sensitive A if the reed is too closed (generally sharp and prone to going sharper with a little more pressure). I have also found that a reed that is too closed affects the second octave E too (behaves in the same way as the A). However, the octave E will be quite flat and will need lots more air to bring into tune if the reed is too open.
Fot those experiencing this sharpening problem, I suggest putting a little blu-tak in the top portion (top quarter) of the tone hole of the E note, and only in the A note if the octave A is going sharp too. I have found that the lower octave E is not so affected by the blu-tak as the lower A is.
Hope this helps.
My flat set is in C, but I have noticed this on my D set, but not as marked.
I have found that A, E and F# (and sometimes back D) are pressure sensitive.
A and E tends to go sharp with increased pressure, while F# (and back D possibly) tend to sink with increased pressure. That makes playing this beast really confusing.
I can lessen the variability in the bag pressure needed to blow them into tune by adjusting the openness of the reed.
I close the reed down until back D, hard D and A in the lower octave all play in tune at the same pressure. This point in my reeds is the minimum opening that won’t give the “autocrann” on bottom D.
I use a bottom fixed bridle, but if you have a movable bridle, you can “adjust” the A pressure by experimenting with the bridle placement and lip opening.
However, I have abandoned the movable bridle because it seemed to create a difficulty in sounding/holding either octave A or B, no matter where I placed the bridle or how I adjusted it.
With a reed with thicker lips such as I prefer (for a stable back D), I have a very stable and pressure insensitive back D, which is great for those A mode tunes such as The Pipe on the Hob.
As far as puttying holes, my C chanter only needs about 1/3 of the bottom of the ghost D hole to tune my Es so they can blow into tune. I put enough in so that the ghost D is faint and “ghostly” sounding, only very slightly sharp of back D.
Sometimes, back D will need a tiny dab of poster putty, and of course, I have a plastic strip bent into a U shape in the bell as well as some poster putty. I adjust the lenght of the plastic strip to better tune the Es and enough poster putty to tune the hard D.
Unlike my concert set, the soft and hard Ds are both in tune on my C set.
Good luck and hope you find the “magic spot”.