Originally Posted by Anon La Ply
18" and jazz ... are larger bass drums in jazz more for concerts?
Don't want to speak for others but for me it's about the right sized drum for the right style of jazz. If I was playing big band I'd use a larger sized drum perhaps. I have my Dad's old 26" Ludwig bass should the need ever arise which is what he used for his big band days.
The style and sound I'm into is the small group music from 50's onward which was generally (not always) played with an 18" or 20". I can and do play the small group stuff from any era with an 18". The drum doesn't need to cut through a big band. That being said, I've used an 18" with a big band and it has worked fine.
Additionally and perhaps more importantly the shell pack market reflects this at least with the drums I play and the places I shop from. A bop kit is generally packaged with an 18" bass. A bop kit packaged with a 20" bass drum is something I haven't come across. Since I'm not willing to fork over the cash for a "customized" cherry picked set, an 18" works well for me.
I would also be remiss if I didn't say, at the end of the day, I love the sound and feel of an 18". It's my favorite size to play.