Until getting my hands on a TH500RP at RMAF this year, I never thought much of the headphone. Sure, they looked nice, but impressions and the one set of measurements I saw seemed lackluster. Not to mention the price was too high. I don't know what it was, but something intrigued me about the pair I heard at RMAF. I really liked the style and fit in person, and that particular pair reminded me of the HE400S somewhat (key word "somewhat"). That was a bad thing, because it got what little cogs I have in my head turning. Sure, the T50RP driver has been modded to hell and back by everyone and their mother, but maybe, just maybe, the driver combined with the TH500RP enclosure would make for a good mod platform. I hate the stock T50RP enclosure and was curious what I could do with the TH500RP enclosure. And then I found a used pair for quite cheap. Oops. It could just be show conditions, but the pair I received seems to sound a little thinner, a little rougher, and a little brighter than the one at RMAF. Maybe. No matter. It won't stay stock for long. Stock, these are sort of a mixed bag. They are definitely lacking in bass, yet still have a bit of midrange warmth to them. Midrange seems pretty decent. They are a bit papery and thin sounding up top, but not in a particularly offensive or painful way. Measurements suggest these have potential just looking at distortion. Surprisingly low for this driver, in my experience, and I even had them running a bit louder than usual. I wonder if these drivers have been refined, cherry picked, or if it all comes down to the enclosure. Part of the problem is that these are too open. I imagine making them mostly closed, on the back side and on the front baffle, will bring out some bass. But I would like to keep some of the semi-open nature if possible. Initial tests closing the back of the cups with my big ol' hands already seem promising. These are also begging to have some damping thrown in the cups. The stock pad and attachment assembly should be good to work from. The pads aren't as thin as the T50RP MK3 pads, though not as thick as the alpha pads or similar. They are slightly angled. I think this will strike a nice balance when it comes to tuning these. I have some particular ideas in mind, but right now, I'm just waiting on materials to arrive so I can get to work. More to come in the next couple weeks!