Monitor Headphones

By Hugh Robjohns

We test two pairs of high-quality closed-back headphones for discerning studio users.

There is a huge number of headphones available on the hi-fi and pro-audio markets, but for our purposes as recording musicians the options are usefully restricted. Clearly, audio quality must come at the top of the wish list, and closed-back headphones are easier to use in a recording environment. It is also inevitable that the headphones will be worn for extended periods, so comfort is essential. Furthermore, they stand a good chance of getting broken through heavy studio use, so being easy to repair is important too. Meeting all of these requirements and more besides are some innovative headphones from Sony — not a name commonly associated with high-quality professional headphones, perhaps, but well worth a closer listen.

There are four models in the MDR7500 series, spanning a wide price range. The top two units are reviewed here: the MDR7506 and MDR7509. These are robust, high-quality designs intended for musicians, DJs and professional sound engineers, and both ship in attractive display boxes with specification sheets at the back. The spec sheets incorporate an exploded view of the appropriate model of headphone, identifying every part (with its Sony replacement order code) as well as showing how to disassemble and reassemble the unit, and how to wire a replacement cable.

Both models feature reversible earpieces for single-sided listening, and the earpieces are articulated in such a way that they can be pushed up to occupy the space within the arc of the headband for neat, compact and safe stowage when not in use. The headphones have a soft carrying pouch in which to store them without the cable getting tangled in all your other leads. The Litz-type cables employ linear-crystal, oxygen-free copper, and have a curly section allowing them to expand to three metres in length if required. They are fitted with 3.5mm jack plugs, but are also supplied with a screw-on adaptor to accommodate the 6.25mm stereo headphone socket standard too.

The MDR7506 (pictured) is the smaller of the two models, with earpieces which combine both supra-aural and circumaural design elements. With my delicate little pinnae they behaved like circumaural units, sitting snugly around my ears, although many users may find they actually sit on their ears instead. However, the headphones are quite light at just 230g, with a well-padded headband and adjustable side extension arms.

The drive units are 40mm in diameter with copper-clad aluminium voice coils and samarium-cobalt magnets to provide a 106dB/mW sensitivity and a maximum power handling of one Watt. The nominal impedance is specified as 63Ω and the bandwidth given as 10Hz to 20kHz (but without any amplitude limits being defined).

The cable enters the left earpiece and a smaller, slightly fragile-looking wire emerges from the back of the earpiece and disappears into the headband to interconnect with the opposite earpiece. Despite this aspect of the design — which is commonly used by similarly priced models from other manufacturers too — the MDR7506 is a robust and practical headphone which is comfortable to wear with minimal leakage of sound in either direction. When not being worn, the earpieces naturally seal against one another too, which can avoid unwanted spill.

The sound quality is very good, with a wide bandwidth and smooth frequency response. Despite being a closed-back design it doesn't sound boxy in the way that many of the more familiar studio-standard headphones often do. This model is capable of delivering accurate and usable monitoring information, with tuneful bass, and natural vocals. While it isn't quite up there with the very best designs in terms of reference clarity and tonal accuracy, this is a very good, cost-effective design which competes favourably with industry standards like the Beyerdynamic DT150 or AKG K270S.

This top-of-the-range model looks the part and features a pair of 50mm dome drivers. The voice coils present a low 24Ω nominal impedance and are capable of handling an impressive three Watts of input power. This may not sound much in comparison to a loudspeaker, but remember that these things are sitting right next to your eardrum, and feature chunky neodymium magnets with a sensitivity of 107dB/mW, which means they can go VERY LOUD INDEED! The quoted response of 5Hz-30kHz (without amplitude limits) sounds optimistic, but the MDR7509s do exhibit a very wide bandwidth, with a deep and powerful bass response which sounds natural without being obviously overblown.

This headphone looks chunky, but weighs only 300g and has an adjustable headband. The earpieces sit around the ear, rather than pushing your pinna