The headband works in two parts with a thin wire structure on top and a thick, perforated pleather pad below that helps with the initial fitting. The ear-cups themselves also cover your ears with a lavish aesthetic; if you prefer subtlety, opt instead for something like the classic Sony MDR-7506 instead.
Design references are subjective, of course, but these rank just above the drab Sennheiser HD-280 Pro in my look book. Small details like contrasting gray-and-black finishes align well with the silver adjustment hinges and the variety of materials used to build the whole thing (rubber, pleather, canvas, plastic and bits of metal), but I just can't shake the notion that JVC used a group of air traffic control headsets as models for the design.
Sartorial gripes aside, the HA-RX900 do have a legitimate weight disadvantage at 12.8 ounces (0.36 kg), and I found myself missing the weight class of the 8-ounce (0.23 kg) Sony MDR-7506 when I felt the cord pulling on the left side of the HA-RX900 during long listening periods.
That could be because of the massive 11.5-foot cord itself dangling from the left earcup that really puts these in the "at-home" or "at-work" class only -- like the Sennheiser HD-280s, I wouldn't recommend them for mobile use, especially since they don't fold up or come with a carrying case.
Still, there's something to be said about the cushioned headband that adjusts easily with a tug that conforms to the shape of nearly any head size. Like any synthetic leather, the cups tend to heat up after prolonged use, so I recommend taking a break every hour or so to rejoin the world and allow your ears to cool off.
I have to ding JVC again for not building user-replaceable earpads into the headphones. A cursory glance at Amazon user reviews shows a number of buyers returning after a year to complain about the glue loosening up and causing the pads to sag. That's an unacceptable oversight even in the budget price range, considering that Sony and Audio-Technica both offer a variety of options in their aftermarket pads for the MDR-7606 and the ATH-M30x.
Sound isolation is a boon for the HA-RX900, and I had no problem achieving a tight seal on the headband and earpads. The circumaural design wraps securely around your head, allowing only minimal sound leaks to the outside world and creating a sound bubble around you to block unwanted outside noise.
JVC boasts about its 50mm Neodymium driver units and ring port structures in each earcup, but I found difficulty in achieving an optimum volume level without distorting the signal. That's not to say the HA-RX900 doesn't sound good enough to be your daily headphone. In fact, most users will experience a pleasing upgrade if they're used to stock earbuds that come packaged with today's mobile devices. I ran them through a variety of sources including an older Marantz 2270 receiver hooked up to a Technics SL-1100A turntable, a Schiit Valhalla 2 headphone amp and a stock MacBook Air, all with pleasing results.
The brass ring on Herbie Mann's "London Underground" record shines strongly with distinction using the HA-RX900s. The band's melodies push through with an even blend, and even the most provocative arrangements are given natural passage in the headphones.
Sonny Rollins' animated saxophone on his "Brass" album are easy to separate from the crisp harmonies of the large orchestral backing, neither drowned out nor pushed aggressively to the front of the stage. Across a variety of genres and media, the HA-RX900 demonstrates a warm balance of contained movement and emotion.
The only exception I would make is hip-hop and electronic music, which usually command an emphasis on lower frequencies at the sacrifice of the midrange. If you exclusively listen to those genres, you'll be disappointed with the HA-RX900's relatively meager bass boom. Instead, check out our reviews of the venerable Sony MDR-V6 or the AiAiAi TMA-1 -- both are tuned for DJs and offer the extra bass boost you want.
The JVC HA-RX900's best feature is a combination of a budget price tag and ample soundstage that suits a few types of music for stationary listening. If you're shopping for a headphone right now to use exclusively at work or at home and can't spend more than $70, the HA-RX900 will get the job done. On the other hand, understand that your list of headphone options will grow considerably longer to include the Sony MDR-V6, the Aiaiai TMA-1 or the Audio-Technica ATH-M50 if you can save up a little more to invest in a pair that will travel comfortably with you anywhere and perform equally satisfyingly across all genres.