I did try to emphasize transparently amping them, as in faithfully amplifying the source waves without distortion, not just about loudness, cause I am fully aware that a terrible amp can bring absurd levels as well.
The only time I tried the 5LE with amps/sources that were supposedly 'significantly better' than my setup (according to the sales guy) was when I was first trying them out in a store to buy them. Unfortunately I don't remember the specific amps I tried, but it sounded to me about the same as they do now with my setup (and yes, I always use the same set of lossless tracks to test out headphones). So I guess I'm now left wondering at around where this 'ideal' level of amp is, and whether it's really that significant of an improvement over what I'm getting now... and what the difference is between that 'ideally powered' 5LE, and a Paradox + O2...
And the denons do have a few harmonics bouncing around in the sub-bass to produce that low rumble (more-so in the D5000's), but they seem to sound like the closest to a small studio setup with a decent subwoofer in my opinion. The mids/highs are another story however, hence I grabbed the 5LE's.