Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Is the hd 25 cord tough?
Document: The headphones are light but seem very sturdy. Unlike the Pioneer and Allen & Heath headphones, I am not worried about dropping the HD-25 on hard pavement. About the cord, I was hoping for a coiled cord with a straight headphone jack. This one has a straight cord with a 90 degree jack. Finally, for the price, I was expecting smoother, more luxurious ear cups.
First, my credentials - my girlfriend and I have owned several headphones, most recently the Sennheiser PX-100, Sennheiser HD 238 and Sennheiser HD 25-1 II (the subject of this review). I have also owned two sets of in-ear monitor phones, the Etymotic Research er-6i and the Future Sonics Atrio.The HD 25-1 II is by far the best.The construction quality is outstanding. They really are tough.
The sound is the best I've heard from any headphones. According to audiophiles, on-ear headphones have less effective noise isolation than over-the-ear models. They are also said to have less powerful bass. That is not the case with the Sennheiser (wow that was tough to spell) HD25.
I really like the quality of the sound on these. But as a DJ, the cord is too short. I also prefer a coiled cord rather than the straight loose version.
The HD25, as you can see in the pictures of it, has smaller ear cups with wires popping up out of them; they also have a much shorter, NON-coiled cord compared to the ATHM50's. Still, the M50's have a noticeably wider sound stage (maybe due to their larger cups, which are about twice the size?)
The cord is a little long for me, but not ridiculously so. They don't get as loud with iPod nano as they have a higher Impedance of 70 Ohms, but even with the iPod nano they will be more than sufficient for the casual listener. When I attached them to my CMOY amp, they achieved a higher volume without distortion than the ATH-M50's.
So far, it's been nine months that I've owned these babies...I use them nearly every day, and boy are they resilient. They've fallen on the floor, out of my car, been stuck in my backpack alongside my computer and schoolwork and the cord has gotten caught and ripped out from my iPod so many times I've lost count. They still work perfectly.
These headphones are exactly what I expected them to be. I am a custodian who works the graveyard shift and needed some sound to keep me company. My first purchase the Audio Technica ATH-M50's were great in terms of sound, although the bass was a little bloated and bled into the mids. My main problem was that the cord was too long to walk around with them, and had to be shoved into my pocket.
Also, every part of the headphone is replaceable, making it easy to buy parts that wear out or break unlike other headphones which become utterly useless if you mess with the wrong cord.As far as comfort goes, although at first they may seem a little tight on your head, after you give them some time to 'break in' and mold to your head, you will find yourself forgetting they are even on your head at times.
Great headphones for the gym, able to be driven by Ipod Nano (6th gen), plastic construction but very durable and feels solid (don't let the plastic turn you off). Great sound quality, great base, long cord (maybe too long for the gym). Split design is good at keeping the phones on the head and ears, no issue. Ear cushions are great but may irritate the ears after a few hours (as with any other on the ear headphone).
Answer: Tough and replaceable