[Ruined]

The main issue with bass traps is they look fugly as hell. Good bass traps are also expensive, from brands like Auralex and whatnot. Even with bass traps, though, you are still not guaranteed success as they only help in certain types of room problems.

Also, the common standard for measurement with speakers is +/- 3db. If a manuf used a more lax measurement as you listed it was likely used to make the sub appear to go lower than it actually does, or in other words exaggerate the sub's actual capabilities. I would consider the specs you listed as a 28hz sub, it sounds like they are trying to bullshit their way into 18hz response which it appears the particular sub cannot actually deliver. And that is also proves my point about how easily specs can be distorted to suit a manufacturer's needs.

As for a seperate EQ module, the one listed costs $749. For the price of that added to your sub you could have had a 1200R. And there is no guarantee an external box will integrate well with any sub. Some subs might not be able to handle the manipulation EQ can provide, bottoming out, overheating, or becoming distorted in some cases. If a sub was built with EQ in mind, obviously that sub speaker and its amp will integrate well with the EQ.

And, re: "audiophiles," I hate to say it but a very large percentage of them are totally clueless. I'm not saying that is the case in regard to said brands, but following "audiophile" advice will these days often will not land you on the best choice. I've tried to dissociate myself from that term which I used to use many, many years ago, because it is starting to become synonymous with those who buy into snake oil. All "audiophile" means today is someone who spends a crapload of cash on audio - it doesnt necessarily mean they spent it on audio wisely.