There are several subwoofers now on the market that "LooK" like the AQHDC series. The basic motor design is a very well known motor in China and is made by several different companies and is used by several subwoofer companies. It's kind of like the Chev 350 engine in that they all look the same on the outside but there are many different variations of the same basic motor.
The subwoofer motor can be, and in our case , built to whatever specs the customer needs to suit their overall woofer design. This includes the gap, pole piece, top and bottom plate, magnet thickness,ID and OD. The combinations are almost limitless. The same goes for spiders, coils, cones, surrounds and every other part that makes up the final design.
Some or all of the parts can be "off the shelf" and some can be custom "tooled" if needed. There are hundreds of spider designs available for the sub designer to pick from and many different coil configurationns as well as the quality and type of wire used to wind the coil not to mention the quality of the glues used. The overall suspension design can be vastly different and still look very much like other designs at first glance.
The methods and quality of assembly can and do vary greatly yet the finished products "look" the same to the uneducated buyer. Price does not always go hand and hand with quality; just because they "look" the same doesn't mean you're getting the same product. I know of one product that "looks" just like ours but comes apart the first time it gets its rated power put to it....well maybe the second time.
The majority of the parts including the motors on most subwoofers on the market today come from off-shore. Most of the sub assembly is done off-shore. The sad fact of the matter is the subwoofer business has become for the most part a Chinese business.
I have found that in some respects China is just like America; there is good stuff and bad stuff...sometimes it's hard to tell the difference.