the ampeg av or PH HE ?i wish i could answer more, but the only one i own is the ampeg, and i haven't been to a music store since late february. there IS less aluminum in the hydrives, and for all i know, the brash tone isn't from the aluminum but are just the way they're voiced. my all-aluminum hartke experience was that i tore the cone of a friend's like tissue paper even while playing way below their max watts.