Sennheiser HD 660S2 Review: Heavenly low end, premium price

These open-back headphones have buttery bass, but they face stiff competition from their cheaper siblings.

Sennheiser HD 660S2 Review

Sennheiser HD 660S2 Wired Over-the-Ear Headphones Black HD 660S2 - Best Buy

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Sennheiser HD 660S2 Dynamic Headphones - Magnificent Musicality — Audiophile Heaven

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Sennheiser HD 660S2 - Reviews Headphone Reviews and Discussion

Sennheiser HD 660S2 review: Legendary reference cans at a high price

Sennheiser HD 660S2 - Reviews Headphone Reviews and Discussion

Sennheiser HD 660S2 Review

Sennheiser HD 660S2 review: a charming smoothness to their sound, but some flaws hold them back

Sennheiser HD 660S2 - Reviews Headphone Reviews and Discussion

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Sennheiser HD 660S2 Review