I have been running a UFO 4/1 Dragstar:
first, w/the bologna-cut 'shorty' tip-really, really LOUD!
second, w/the UFO megaphone, really-loud but a step-down from the above
third, a Frankencanister from a literbike sportbike, greatly-reduced from either No. 1 or No. 2
and now, another alternative...