Another great option is Martinelli's 17" horn. Since it's a little larger, it can be used at a lower frequency. It will work just as well up high and looks very attractive with the Professional Series seven π speaker because the width of the horn matches the width of the cabinet.

Stage Series seven π loudspeaker at MAF 2003

The speaker shown above is a Stage Series seven π loudspeaker in the hotel room at the Midwest Audiofest. The Professional Series seven π uses the same size cabinet, so they look the same.

Is there any plan for Martinelli 17" horn ?

I also looked at this interesting site: http://vincent.brient.free.fr/pav_ronds.htm
describing relatively easy way to construct round horn...looks
interesting.

Another Q: how important is sonic difference between stock eminence
plastic horn and good dessigned wood horn ?

thanks, v

I think he'll sell the lathed billet aluminum throat by itself if you have woodworking skills and want to make the rest of the horn yourself. If you've got a machine shop for the throat section, you won't need that. But if not, I'd contact him - Having a metal mounting plate for the driver is a big plus. It's got an O-ring to ensure a good seal with the driver and since the mounting plate is metal, it won't wear out and chip when installing and removing compression drivers like horns with a wood plate might.

Keep your ears and your mind open.

I will start with stock Eminence H290 and I will try to build
som wood horn maybe latter :-)

v.