As the adage goes: if it ain’t broke don’t fix it. Sennheiser certainly has taken that to heart, and the new HD 660S2 is Sennhieiser’s attempt to yet improve on a beloved classic with tweaks and improvements. The HD 660S2 is a refinement of the HD 660S, which in itself is (arguably) a refinement of the HD 650, which has been in circulation since 2003.
This time around, Sennheiser says that they’ve improved the transducer airflow and got the magnet’s air gap to work more efficiently, which drops the resonant frequency from 110Hz on the original down to 70Hz. The result, according to them, is greater precision, speed, and resolution with double the sound pressure at the lowest frequencies, which helps the precision of the sub-bass.
Meanwhile, the reduced voice coil weight improves impulse response and improves realism. Sennheiser adds that the tuning reduces the distances between select peaks and troughs, resulting in a smoother and warmer sound compared to the original HD 660S.
Apart from that, it’s pretty much the same headphone; 300 ohms overall impedance; designed in Germany and made in Ireland, and it ships with two 1.8-meter user-detachable cables that terminate to 6.3 mm single-ended stereo and 4.4 mm balanced stereo plugs, with a 6.3 mm to 3.5 mm adapter included.
The Sennheiser HD 660S2 is priced at SGD899 and is available at the Sennheiser Consumer Hearing webstore and authorised retailers.