Bass may be the single most important sound characteristic people focus on when auditioning headphones. There's either not enough or too much bass, or it's too thick or boomy, and getting just the right balance can be tricky. I like bass, but it has to be clear and well-defined, and Audio Technica's new ATH-WS55 full-size headphones ($100) are exceptional in that regard. Before you get the wrong idea, the ATH-WS55's midrange and treble are just as pure and detailed as the bass.
It's a lightweight (165 gram) design and features Audio-Technica's new Double Air Chamber System that focuses the "air flow" produced by the driver to enhance bass output. I have no idea what that really means, but the results speak for themselves. Comfort was fine, but the nicely cushioned faux leather earpads' pressure against my ears was moderately high. The headband is also cushioned, and overall build quality feels decent. Sensitivity is only moderate, so the ATH-WS55 may not play loud enough to suit some buyers' tastes. Even with my iPod Classic's volume turned up nearly all the way it didn't get super loud.
While I listened at home with the Topping TP-30 amp the headphones could play louder, and the definition of the drums and bass underpinning Amy Winehouse's "Back to Black" album were impressive. The Sennheiser HD 555 open-back headphones ($170) sounded more "open," and less inside my head, but for a closed-back design, the ATH-WS55 didn't sound too closed-in. The prime sonic difference between the two sets of headphones was that the ATH-WS55 was more detailed and clear, the HD 555 more laid-back and soft. At home with the Topping amp, the ATH-WS55's sound, especially the bass, handily trumped the HD 555. Those headphones were more comfortable to wear for extended periods.
Sticking with the iPod for the duration of my listening tests the high percussion accents and pounding bass drums on "Prologue" from the "Birth" soundtrack sounded balanced and accurate. I wished the orchestral strings were a wee bit sweeter, so the ATH-WS55's sound isn't perfect. Then again, I'm unaware of any $100 headphones that will do better with strings than the ATH-WS55. The bass definitely didn't cloud over the midrange the way the Klipsch Image One headphones did on the "Birth" soundtrack. Granted, the Image One's bass is fuller sounding, but to my ears it seems like too much of a good thing compared to the ATH-WS55's tauter bass balance. The vocals and background choir on "In the Hands of Angels," from the Elton John - Leon Russell "The Union" album sounded more natural on the ATH-WS55 than the Image One, which seemed to place the singers into the background.
Listening to recordings I made on the Zoom H1 portable recorder of my friends singing and playing in their living room confirmed the ATH-WS55's natural balance. The sound transported me back to the living room, it was that good! The ATH-WS55 is a sealed-back headphone, but it only does a so-so job blocking outside noise. The headphone lacks any iPhone controls or a mic, which might be a deal breaker for some buyers. As much as I love the sound of the ATH-WS55, and the bass balance strikes me as ideal, I'd concede these headphones might not light the fire of buyers seeking a fatter, more prominent bass fullness.