Sennheiser HD1 In-Ear / Momentum In-Ear vs Sennheiser IE 40 PRO

The Sennheiser IE 40 PRO are slightly better critical listening in-ears than the Sennheiser Momentum In-Ear. They are better-built than the Momentum and have slightly better audio reproduction. On the other hand, the Momentum might be more versatile for casual listening thanks to the in-line remote, and their fit blocks more ambient noise, which will be better for commuting and traveling. They also have an in-line microphone for calls that the IE 40 PRO doesn’t have.