The HTX7 present similiar detail as my Shure E500 (ok, maybe just a bit less). Is a bit sibilant at times. Mids is ok. Bass amount is decent, thought maybe a bit uncontrolled at time. Overall they're enjoyable and very good for their price. (I got the HTX7 plus a mini camera tripod for about $37 shipped at buy.com with google check out discount).
Finally getting the Panasonic RP-HTX7...after 60+ hours burn in they're worthy headphones to be mentioned. Especially at $32 these panies proved to be another KEEPER for me.
I just LOVE good cheap headphones. The HTX7 could be another bargain headphones out there for sure.
Personally I really like the retro look, build quality and material finish on these HTX7. Also the comfort is better for me since I have big eye glasses frame. Before the k81 (supraural) used to sit on my ears pressing toward the frame. Now the HTX7 (circumaural) sits around my ears thus no pressure. Only gripe I have with the HTX7 are the sweaty ears due to the oval pleather cushion covering my ears. Well this only happens after hours of listening. Soon I'll post some detailed pix of the HTX7. However, I think k81 build quality is far more durable and sturdy for sure. Its rubber coat paint on k81 make them scratch-proof and grippy tactile.
The HTX7 headband has perforated pleather metal band which houses two thin metal arm frames. The glossy plastic finish on the cups look like expensive lacquer finish. Also the machined metal parts gives the killer pilot look. I would say the size of the cups are about the Sony eggo series, very compact in its elliptical shape.
The k81 is definately far more portable. The HTX7 are small and compact, but the aforementioned metal rail arms don't fold nor swivel nor rotate to make it portable. Before I forget, they don't come with a nice headphone pouch bag. So as the portability is concerned, the k81 shines in every regard.