the odds are that the Aiwa's, like a lot of inexpensive speakers, had a "mid-bass hump", or increased output around 100 Hz, before they tapered off quickly. I bet they had little or no output at the low bass end. Such a frequency response gives an impression of more bass tho it is really a bit of a deception.
From what I've read, the ae5 has nice well proportioned bass and maybe your aiwa's had that exaggerated version (farty, as you note). I don't know for sure but that's what I suspect.
If you want more then ae does sell a matching subwoofer...

picking up RF interference - others can advise better than me. cables should be shielded. do you pick up RFI on radio or other formats? are the ae's running off a computer, or a cd player, or what?

Ditto what Bill said about the bass. What you're hearing is more accurate bass- tighter, faster, but without filling in what's not there. That's what allows more of the other music to come through too. Lesser speakers almost always boost the mid bass to fool you into thinking you're getting "good" bass but it's usually a sort of "one note" boom and not very musical.

The stray interference is weird, but am I according to the literature on The AudioEngine 5's they are "wireless ready," which is probably the culprit. Can that feature be turned off by any chance? Apparently they are working a little too good in that capacity.

BTW: the next time your doing work in Salem give me a ring (since I work from home). I'll give you a little demo of my system, and you can hear for yourself just what all the fuss is about with the audio "high-end." The only warning is: once you've tasted it, it's not always easy to go back.

Glad you found some good speakers with some help from the Forum!

Yeah- well I can't say I'm anywhere near that deep into it either- my speakers are a mere 43" high! I don't have 95lb mono block amps, and my turntable isn't $15k! However: You can get some great sound from well below the threshold of Rolls Royce audio.

Best,

Doug