Sennheiser has expanded its 600-series family with the launch of HD 660S2 headphones in India. The headphone has been priced at Rs 54,990. The company said that the HD 660S2 headphone has been crafted in a way that skillfully balances reference-level detail with engaging frequency response. The headphone features a more dramatic listen with greater intensity from enhanced sub-bass tuning, extracting dynamic impact and emotion from audio enthusiasts’ favorite recordings.