The difference between Solo 4 and Studio Pro lies primarily in their design, features, and sound quality. The Beats Solo 4 is a more compact, on-ear headphone designed for portability and casual listening, featuring improved battery life, enhanced comfort, and solid audio performance with deep bass. In contrast, the Beats Studio Pro is an over-ear model that offers active noise cancellation (ANC), superior audio fidelity, and spatial audio support, making it a better choice for immersive listening experiences. The Studio Pro also boasts lossless audio support via USB-C, upgraded adaptive ANC, and Personalized Spatial Audio, making it more suitable for audiophiles or professionals. While both models prioritize Apple and Android compatibility, the Solo 4 leans toward affordability and lightweight convenience, whereas the Studio Pro provides premium features and superior sound isolation. Ultimately, the choice between the two depends on whether you prefer a portable and stylish on-ear experience (Solo 4) or a high-fidelity, immersive over-ear sound with advanced features (Studio Pro).