We've put together a comparison of these two impressive headphones GRADO SR325e vs Sennheiser HD 660 S. Based on our rating, SR325e has a total rating of 7 out of 10 vs 8 out of 10 for HD 660 S.
The Sennheiser HD 660 S is better headphones in this comparison. Check Sennheiser HD 660 S price