Anyway, when they began the production with this softer and bad quality plastic material (PVC?), they didn't modify the moulds. And the air duct and labium specifications which were adapted to the hard and vibrant polystyrene, went off the "best setting range".
The most usual criticisms against the current Humanatone is that it produces a weak and hoarse whistling. Some other players don't like it's tone range. This is mostly attributed to its too broad mouth hole, too thick air duct, and the absence of a real "blade fipple". Some Japanese players made experiments with cellotape in order to reduce the mouth hole, and it gave some correct results (see here and there).
What we present here is a more significant modification, more permanent, yet made in less than one hour. The idea was to improve the power, the range, the precision and the clarity of the sound.
First I cut a little piece of aluminium in a 2mm thick plate, and filed a bevel. Then I filed the rear side of this future blade in order to create a little step just besides the part of the labium that was designed to inset the mouth hole. I just glued the new aluminium fipple with a bi-component glue.
Here is a little sound sample of a regular Humanatone immediately followed by the same excerpt with the improved flute. The recording conditions were absolutely the same and I took care of trying to blow with the same strength (the improvement is patent, thus not totally palpable with this mp3).