Although Sennheiser has transferred headphone production to another company, it continues to expand its iconic HD series. The 25-year-old Sennheiser HD series has become even stronger with a new member, the HD 660S2, with an open, surrounding-ear design. HD 660S2 stands out to deliver a clear and clean audio experience and is considered the best model in the series.
The HD 660S2 doesn't offer features like active noise cancellation or wireless connectivity; but this does not hinder the superior sound quality in any way. Equipped with a 300 ohm transducer, this headset can reduce the frequency to 70Hz.
The headset offers two different cable options with 0.25 inch and 4.4 mm jack input. You can connect it to a booster with the help of a 1/8 inch adapter and thus use its full capacity. However, due to its open design, it does not have the feature of blocking noise in crowded places.