Body and Construction
The Yamaha RBX170 has a solid alder body, while the Squier Affinity P Bass has a poplar body. Alder is a denser wood that produces a brighter, more articulate sound, while poplar is a softer wood that produces a warmer, more mellow sound. The RBX170 also has a bolt-on neck, while the Affinity P Bass has a neck-through-body construction. Bolt-on necks are easier to remove and replace, while neck-through-body constructions provide better sustain and resonance.
Pickups and Electronics
The Yamaha RBX170 has two single-coil pickups, while the Squier Affinity P Bass has a single split-coil pickup. Single-coil pickups produce a brighter, more articulate sound, while split-coil pickups produce a warmer, more mellow sound. The RBX170 also has a three-band EQ, while the Affinity P Bass has a two-band EQ. Three-band EQs give you more control over the sound of your bass, while two-band EQs are simpler to use.
Hardware
The Yamaha RBX170 has a die-cast bridge, while the Squier Affinity P Bass has a vintage-style bridge. Die-cast bridges are more durable and provide better sustain, while vintage-style bridges offer a more traditional look and feel. The RBX170 also has chrome hardware, while the Affinity P Bass has black hardware. Chrome hardware is more durable and easier to clean, while black hardware gives the bass a more classic look.
Price
The Yamaha RBX170 is typically priced around $200, while the Squier Affinity P Bass is typically priced around $150.
Conclusion
Ultimately, the best bass guitar for you is the one that feels and sounds the best to you. If you're looking for a bright, articulate bass with a solid alder body and a bolt-on neck, the Yamaha RBX170 is a great option. If you're looking for a warm, mellow bass with a poplar body and a neck-through-body construction, the Squier Affinity P Bass is a great choice.