Amp for rock/metal with high efficient speakers

I think Bigjoe said it best, I know what you're looking for, I have a pair of re-built/re-finished JBL-L200's circa 1973 and whereas with older 1960's jazz records, say Louis Armstrong with Duke Ellington, a tube amp is right, however with Robin Trower or Jeff Beck I think a good Krell, Bryston, or especially a Threshold 150 watter would do the trick.
Something about those 15" woof woofs! a certain visceral impact that smaller subs cannot emulate IMHO.

some PA systems by JBL contain 10" "mid" drivers... basically if the woofer is 18" or 15" then 10" sounds kinda small.. you want to be on-axis when listening. midrange in this respect is probably between 350 and 2200 Hz. Older two way designs of course used 10" woofers crossing over to a tweeter in the 2k range: Dynaco's, Advents, JBL's, AR's, EPI, etc.