I have begun using Acoustic amplifiers in the last few months and as I am trying to learn more about amps & cabinets from the 70's I see that Acoustics in particular really used 18" cabinets w/folded horns. I do not see that much when looking at bass cabinets that are popular today. Can someone please shed some light on this for me? I am wondering: Am I just not noticing folded horn cabinets b/c I wasn't looking for them (NOTE: I know that it is easy to find them when specifically looking, I am more curious as to why I don't see AMPEG, ACCUGROOVE, SWR, etc,etc folded horn cabinets, etc) or Has technology been developed that made that particular design a moot point? Thanks for any info. Oh, wait; as long as we are on the subject: Can anyone speak on the difference in tone/freq. response/ whatever between various popular size cabinets. I.E. 2x15" vs 1 18" vs 2x12" vs 4x10" and such.