Open-back Sennheiser HD 660S2 headphones boast wider soundstage and crisper low frequency response

Open-back reference-level headphones are something audiophiles can’t part with, more so, when they are from the acclaimed Sennheiser HD 600 series. Right from the HD 600 introduced in 1997 to the current era HD 660S, the German audiophile brand has come good on the expectations of the most demanding music listeners out there.

Sennheiser’s newest member in the series are the HD 660S open-back headphones that address the most common irk with the HD 660S. Yes, I’m talking about the low-end frequencies in your favorite hip-hop, EDM or Rock songs. So, one can expect deeper and clearer bass levels without compromising on the expansive soundstage details.

Designer: Sennheiser

The sensitivity across all audible frequencies has been tweaked slightly so that the listener can hear sounds never heard before. Impedance on them gets a bump up thanks to the improved 300 ohms (150 ohms on HD 660S) transducers. This lowers the resonant frequency from 110 Hz to 70 Hz so that the hefty kick drums are audible in clear detail.

On the design front, nothing much drastic has been changed in the choice of material and the overall look. The pair of cans weighing 260 grams are crafted in Germany and hand-built in Ireland bearing the same velour-wrapped foam headband and earcups, acoustic metal mesh grilles and folding hinges. One thing that’ll make them distinguishable from the earlier model is the presence of the bronze accents on a jet-black finish.

Just like any other open-back model on the market, the Sennheiser HD 660S2 headphones are best suited for at-home listening. They are intended for audio purist, and don’t come with any ANC or wireless connectivity option. That said Sennheiser has paired them up with two 5.8 ft user-detachable cables that have a 1/4-inch single-ended stereo plug and a 4.4mm balanced stereo jack plug. The package also includes a 1/4-inch to 3.5mm adapter.

The Sennheiser HD 660S2 will be up for grabs on February 21 for a price tag of $699.95. Clearly more expensive than the feature-rich Sony WH-1000XM5 or Apple AirPods Max, but as I said, these pair of cans are for hardcore audiophiles who value audio quality more than anything else.