Create Your Own Signature Sound with RP Technology

Unlock a new level of customization in personal audio with the Fostex RPKIT50, a headphone assembly kit built around the proprietary RP (Regular Phase) diaphragm technology. Whether you're a discerning music listener or a professional audio creator, the RPKIT50 lets you craft a headphone tailored to your exact preferences.

This unique DIY kit allows users to experiment with various components and tuning materials to modify the headphone’s tonal characteristics. Fine-tune your setup for musical enjoyment or critical studio monitoring—the power is in your hands. The flat drive diaphragm design delivers accurate, phase-consistent sound reproduction with impressive input power handling and customization potential.

Key Features

• Includes proprietary RP driver units for precise, detailed sound

• Customizable tuning with sound-absorbing materials, dampers, and sheets

• High input capacity (3000mW) for versatile use in studio and high-fidelity setups

• 89–92 dB/mW sensitivity for balanced output across various sources

• Assemble-your-own headphone experience with included cables and accessories

Technical Specifications

What’s in the Box

• Semi-finished headphone body × 1

• RP driver units × 1 pair

• Synthetic leather earpads × 2 pairs

• RP unit gaskets × 1 pair

• Tuning dampers for baffles × 2 pairs

• Sound-absorbing materials × 5 types (1 pair each)

• Tuning sheets for housing:

  • Non-woven × 6 sheets

  • PET × 6 sheets

• Sound absorbing material for baffle (5 mm × 100 sheets)

• Tuning dampers for RP driver × 1 pair

• Mounting screws × 6

• Unbalanced cable (Φ2.5 to Φ3.5, 2m) × 1

• Balanced cable (Φ2.5 to Φ2.5, 1.2m) × 1

• Conversion adapter (Φ3.5 to 6.3) × 1

• Fostex logo sticker × 1

Applications

• Professional studio headphone customization

• DIY headphone projects for audiophiles

• Music production and mixing monitoring

• Education in audio engineering and design

• Experimental tuning and sound testing