In Grado's pricey range of headphones, the SR225 come in at mid level, $200. There's not much to choose between the various models of in terms of their appearance, and they all look quite like the classic Stax SRX even though the latter was machined in light alloy and used the electrostatic principle.
The casings of the 225's are molded in black plastic; the active mechanism is a full range moving coil driver much like a small loudspeaker driver unit. These cans rest on the ear (supra aural') and are fairly light at 170g, with good range of adjustment, thanks to the effective two-axis gimbal design. The cable is quite thick and heavy, doesn't suffer from the self-noise and if left to hang free, does add additional weight to that already worn. A gold plated jack is fitted (full size 6.3mm type). Use with a Walkman requires an adapter and with these headphones' moderate 92dB sensitivity plus lowish 32ohm impedance, a powerful Walkman would be required. For the enthusiast, consider a good quality auxiliary headphone amplifier. The effective cable length is 1.5 meters so you need to sit pretty close to your sound source.
These are open backed phones, which by definition have no isolation from stray noise and do emit some audio leakage of their own. A special foam is used for the ear pads, which I found rather itchy. For long term listening use I would be tempted to stick or sew very light rings of chamois leather or similarly light cloth over the contact region. They weren't felt to be particularly impressive on first hearing; but after further use, the SR225 claimed a place close to the top of the moving-coil headphone stack. They provided significantly deeper bass than the competition; using appropriate material, they gave an uncanny impression that a sub woofer was also operating, acoustically blending via the open back of the cans. The bass was powerful, deep, tuneful and enjoyable. It proved valuable in conveying a fine sense of scale to the replay. A mite distant, the midrange avoided the over-punchy 'right in your head' effect of some of the more raucous headphones, In fact the very fine recovery of ambiance and offstage imaging gave surprisingly spacious sound effect. Large stereo stages could be easily imagined. No boxy or nasal coloration's affected the mid which leads smoothly to the lively, open treble, sounding clean both on sibilants, and crisper, more complex percussion, reaching confidently to the edge of audibility.
Transparency was a key attribute of the SR225; a high-end quality for the recovery of low-level detail and an easy clarity were both in evidence.
Sounding very good at both low and high levels, these headphones are of reference quality both for the classical virtues of neutral frequency response and low coloration, as well as for their clarity and the high degree of listener involvement invoked.
While the build, finish and comfort didn't match the equivalents in the Sennheiser range; the standard was more than satisfactory. The results were exceptionally good for sound quality, with a particularly clean, extended bass; this is a costly moving coil headphone, but I feel that it provides a commensurately standard of music replay and is firmly recommended.