Help! Gemshorn won't make a sound!

[Andrea Kirkby]

I have spent quite a long time carving and fitting maple blocks to a pair of horns, and carving out the window and the ramp, using the instructions given on http://www.personal.utulsa.edu/~marc-ca ... hgems.html

Basically, a 10mm x 4 mm window, a ramp about 12mm to the labium, a 1mm deep windway cut in the block. I've smoothed the labium, which was a bit rough...

And ahem. Nothing happens.

I've tried adjusting the windway with masking tape to close it up, but that doesn't seem to make any difference.

I've made recorders, and they play - okay, badly! - but they do play pretty much as soon as the block and labium are in place, and then it gets better as you do the voicing. But I've never had nothing before.

Any ideas? I'd be very interested in hearing from people who have successfully made gemshorns. I have a ready supply of cheap horn if I can actually get the darn things working.

[Yuri Terenyi]

The first two-three-four inches or so of the horn material wit the labium carved in it need to be reasonably aligned with the wind stream. Which is why the recorders work for you, and the horn doesn't. I suspect it curves away downwards practically immediately.