Tang Band W6-789E 6-1/2" Woofer

Title says it all

First of all, the audio signal limit is past 30w--the 15w figure is specific test conditions unrelated to actual application. With 4mm xmax, it handles at least as much power as the average 6-1/2" driver, not less.
Second, the usable box sizes don't directly relate to the T/S specs. It can use 0.5 and 0.7 cubic foot boxes at least as well as the average 6-1/2" driver. Yes it does hit the low notes, and quite loud!
Third, the free-air efficiency isn't 91db, but its close--so that's better than average for an 8 ohm driver. Once in a ported box, the efficiency goes at or over specs.
Third, the chart is no lie, and the crossover is as easy as indicated. It can play high enough to use the more beautiful parts of tweeters, like the 3/4" cloth dome from Pioneer, or even a TI dome.
The paper cone is the wonderful high-speed coated stuff, while the dust cap is nice quiet non-screech fiber. THANK YOU, TANG BAND!!!
Despite looking "advanced" and the specs looking scary, a beginner could probably get some rather aggresive, high fidelity, in under half an hour. For the experienced, the crossover might take about eight minutes to complete.
The very, very short timeframe for success and the sheer power make this driver a bargain at its price.

I built a large (2cuft) 2 way vented speaker (w/3k dayton crossover and 1" tang band dome tweeter 25-302SH) to be powered by a T-amp. With less than 15 Watts driving it this woofer can produce some amazing low bass (flat down to 40 hz) AND has excellent sound quality up to the 3khz crossover point. Its now hooked up to my Yamaha receiver with even better results. I can listen to movies at theater volumes without needing a dedicated subwoofer. This two way speaker setup has some startling good imaging and SQ that took some getting used too. I thought an intruder was in my house the first time I heard vocals from these while I was in a different room.

Pros: Amazing low bass, excellent sound quality, high efficiency
Cons: Needs a big enclosure for good results, listed low power handling (they get plenty loud for those of us that value our hearing).