When designing your own headphones, the internal hardware is as critical as the external aesthetics. You must specify the Driver Type (Dynamic, Planar Magnetic, or Balanced Armature) and size (typically 40mm to 50mm for over-ear models) to ensure sound quality. For wireless versions, insist on Bluetooth 5.2 or higher and support for high-quality codecs like aptX, AAC, or LDAC. Additionally, define the Frequency Response range (standard 20Hz-20kHz) and Impedance levels based on whether the target user will use a mobile device or a professional amplifier.