The source makes a difference. Amping makes a difference, with or without a separate amp. The bass boost of the E5 surely would help. The PA2V2 amp probably would help too. Will the bass of the AD700 satisfy listeners A, B, and C with set ups 1, 2, and 3? Depends. Maybe, maybe not. People have different expectations and preferences. Here's what could happen. The AD700 is bought, but the bass is found to be lacking. The chase begins for a better source and amp to make it sound more like the bass you want. Improvement is found; however bass nirvana is never obtained. I've held off on buying the AD500 or AD700 for one main reason; I like heavy hitting and powerful bass. Not the kind that mucks up the mids and not the kind that sounds like its coming from the trunk of a car. I just don't think the kind of bass that I like can come from the AD500 or AD700. Of course I haven't heard either with any source or amp, so I could be wrong, but I doubt it. Not bashing these headphones because I am sure either could be enjoyed very much with the right combination of equipment and the right kinds of music or uses.