IE 900 EarphonesA New Benchmark in Personal Audio Introducing the new flagship IE 900 earphone from Sennheiser. Sennheiser headphones have long appealed for audiophiles, and their earphones can compete with the best of them. Replacing the IE 800S, the IE 900 embodies the peak of German audio engineering and manufacturing. Every aspect of the IE 900 has been engineered to work in harmony to achieve the desired acoustic tuning and to reduce resonances and masking