I'm a proud owner of the budget cans, JVC HA-RX900 and I'd like to tell you the story of how I took the simply 'a little better than average' in it's price range headphone and made it (in my opinion) drastically better. At first I was reading this lovely thread by TopPop http://www.head-fi.org/t/381303/jvc-ha-rx900-modifications-a-picture-tutorial-56k-forget-about-it on how to modify these JVCs and seriously desired to improve my JVCs because their highs are lacking and they have a slightly unnatural vibe to their sound. I searched around my local stores for dynamat and acoustic stuffing, but to no avail could not find them at all. So like the immature, antsy teenage boy I am I bought other materials I thought might be good for modding, which ended me up with modeling clay, a bag of cotton balls and some think felt sheets.
I opened up the JVCs and packed the cup with red and blue clay after removing the felt ring covering the drivers (each side respectively) and topped it with a layer of similarly colored felt (cut into pieces to fit the depressions and places I was putting it in) until I had a decently covered internal cup surface. I tried a quick comparison (right to unmodded left) and noticed an up in clarity and a more smooth sound in the modded side, bass was unchanged. I decided to add a layer of cotton in a few different thicknesses and it sounded to me like it was unnaturally skewing the sound for the worst and made the highs sound similar to how poorly compressed mp3s sound, --- and for some reason didn't effect the bass too much. Knowing that without the proper materials I could never achieve the same results as TopPop so in my last efforts I decided to do something a lot more extreme. Remove the cups a.k.a. openify the JVC HA-RX900.
The RX900s design didn't make removing the cup an easy job... in fact, I handled it in an extremely brutal and unprofessional way. I took a utility knife and pried the metal plates off each side and twisted the knife into the plastic to create a lot of holes and continued to do so around the surface of the cup, inefficiently and ruggedly opening them up. Of course, halfway I compared them to the partially modded side that was still closed and the now opened side. They were the same in sound signature but the open side improved drastically without any downfalls, miraculously. The frequency response seems to have lost most of it's irregularities and awkward dips and spikes, and the bass seems to have went up a notch in both quantity and naturalness, the extension and quality doesn't seem to have changed much (if at all) but I've noticed it's slightly more impactful and quicker in general. Of course, now that it's open it's lost what little isolation it provided (really, it didn't block much to begin with) and at the same time leaks a lot more sound (which it didn't leak too bad to begin with). The soundstage is fairly large, definitely more than it started with without a doubt and one of the only flaws in it's sound is it's weaker imaging ability, --- which mostly is noticeable with less-than-bright vocal tracks (the lower midrange likes to blend) and I can't say I remember if this was a problem or not with the stock sound (probably), but it doesn't matter because I really love their new sound. At 50$ and less than 10$ in supplies mixed with a bit of effort their sound easily rivals headphones twice that price. (around and under 150) I can't comment on how well it fairs against other open headphones under 200$, but it's definitely still affordable enough for those curious enough to test it out.
Here's some pics of my ugly yet beautiful and highly loved JVC HA-RX900 v2:
Feel free to question, comment and even throw some advice at me regarding my experiment. I'm all ears and this may be the first but won't be the last DIY job I do. (I just hope this isn't a consistant quality of work ;) )