Huh - I didn't know you were such an Epik fan, BMX
I'm the other side of the coin. I'm not saying it to "knock" Epik or BMX - they're certainly not "bad" subs or anything. But I'm not a fan, and I just like to let people know my honest opinion so that they can make up their own mind. It's really easy to get sucked into the hype, especially if you are already leaning a certain way. Very often, folks are looking for some sort of "consensus" about products. There are a lot of Epik fans, and with good reason. But there are also a number of us who don't think they're "teh greaterest thingz EVAR", so I just say "on the other hand" so as to balance the praise a wee bit
While Epik's current two models are both dual opposed driver designs in sealed cabinets, they don't actually output the natural 2nd order roll off of an unaltered sealed design. Instead, Epik uses an EQ boost in the amplifier to make their subs play flatter down to 20Hz-ish (normally, without the EQ boost, they'd start to roll off up around 40Hz with the gradual 12dB/octave slope). Below that, they put in a filter so that the slope is pretty steep - basically the response sort of mimicks what a natural ported design would deliver with flatter response to a lower frequency, and then a steep roll off below that point.
Absolutely nothing wrong with that design choice! But it's just something to be aware of as you are not getting the natural roll off tendancies of a sealed design is all. The other thing that comes with that design choice is higher distortion. In essence, that EQ is just turning up the volume on the low, below 40Hz stuff. And as you crank up the volume, you get higher distortion as the drivers are forced to move more and the amplifier is dumping more power into them.
Epik gives you a lot for your money, there's no doubt about that! But you also have to be aware that there's no magic going on. They're selling dual driver subs for similar or lower prices than single driver subs. They aren't selling them at a loss. They're using a little bit less expensive drivers so that they can keep the price down. Again, nothing wrong with that - they're choosing a design and aiming for a price point and doing what needs to be done to hit it. But you do get a little bit lower quality drivers just due to the price point. Personally, I've found the end result of all of these design choices is that Epik's subs don't sound quite as "clean" as I would like. They've got a little bit of overhang. A little bit of delay in the transient response. A little bit of audible distortion at loud listening levels.
And I stress here, "a little bit". I'm being very picky
I just personally prefer what some of the competition offers because I tend to favor "tightness" over extension if I have to make that choice. So I personally like the Rythmik FV12 better than the Legend in the $500 price range. And I personally like an SVSound PB12-NSD or HSU VTF-3 MK4 over the Empire in the under $800 price range. But it's a personal preference and I can understand how other people would prefer the Epik subs in those price ranges. Again, I just offer my opinion as a bit of a "counter balance" because otherwise, it's easy to think that "nothing beats an Epik at ANY price", and I just don't think that's the case. They're good subs, I just don't personally think they're "the greatest". I fell into the Epik hype too at one point and wound up disappointed. Not because the Epik subs I bought were "bad". They weren't. But simply because they weren't quite to MY taste. They had a few nit-picks that I think are worth mentioning, so that's all I'm doing
One of the things that happens a lot on message boards is that people are upgrading from a HTiB sub or a really cheap sub to a "proper" sub for the first time. So of course they're absolutely blown away by what an Epik sub sounds like! They've every right to! But in their excitement, they'll also get carried away and praise it a bit too much, and say things like, "I can't even imagine how any other sub could be any better!" You read something like that and it's hard not to get caught up in the hype!
But if you've been in the home theater game a long time and listened and compared a lot of great subwoofers, then you start to realize that even good subs like Epik's can still be improved upon in some areas, and you might even prefer something else in the same price class.
So no knock here. If the Epik subs float your boat, I have no beef with that! They're not MY cup o' tea. And I don't think they're necessarily the very best choice for EVERYBODY. They're the right choice for some folks though. So it's just a matter of matching a person's taste and their room and their associated equipment to the very best match possible. It might be Epik. It might be something else. But just don't get caught up in the hype