What about the Athena 4000 compared to the Dayton sub-120?
Some people say that the Athena is better and the Dayton is a "1 note wonder"..
As we all know good bass is incredibly expensive. You can buy a speaker that's incredibly accurate from 50hz up (aka Ascend Acoustics 170SEs) for $350 -- +/- 1db 55-27KHz...(yes, I did say ONE decible).
However for a system that's that linear for the last 45hz...say 15-50hz +/-2db, you'd be looking at, at *least* a $750-$1000 subwoofer. It takes so much physical excursion to belt out those lows, it's just hard to do it on the cheap.
The Dayton is a good subwoofer for a first time (non-multimedia) buyer. It has very little output below 40hz--by this, not in the multimedia subwoofer sense (you can't hear it), but a more stringent measurement--it dives beyond this point, it's -10db at 35hz. The older Athen ASP-400s, while lacking power and SPL, were more linear than the Dayton's--Tom Nuissance (sp?) who measures many commercial subs, found the Athenas to measure within the +/- 3db spec down to 31hz. Much more impressive "musically" I suppose.
I wouldn't say the Dayton's aren't musical or "one note wonders tho. Since they can't reproduce much below 40hz, there's not much room for THD peaks (like you would see in say a multimedia PC subwoofer, which are poorly EQed). More like it plays the notes it can, but since it doesn't *try* to reach deeper, the upper bass isn't exaggerated by THD peaks (as all overEQed drivers will have THD peaks when trying to extend beyond it's natural bandwidth--in the case of the old Z-680 Logitech subwoofer I had, I measured a +45!! db peak at 90hz when playing a 30hz test tone.), so it is free of being a "one-note wonder" like many PC subwoofers.
The Athena ASP-4000 on the other hand looks like a totally different (possibly inferior?) design, and looks like it was built more for mass market consumption in mind. I don't think it would be as linear as the older 400s, but it looks like it's been armed with a better amp for more SPL/output.
As for the X-530s vs the Z-5300s....when I demo them in stores, I can't even hear the differences between them anymore. They just all sound the same. It's hard to differentiate "ehh" and "a little less ehh" after you are in high-fi. This is not audiophile snobbery. This is turning on LOTR when the King of Rohan is knocking his sword against his cavalry's spears and hearing all these intricate rings...when your roommate who thinks spending any money on audio is foolish goes "holy sh1t dude..."