Why Do IEMs Sound Muffled?

If your in-ear monitors (IEMs) sound muffled, dull, boomy, or unclear, you’re not alone. Many listeners experience this, even with high-quality IEMs. The good news? Most causes are simple, common, and easily fixable. This guide explores the most common reasons IEMs sound muffled—and what you can do to restore clarity. 1. Poor Seal or Fit