How to say "hi-fi" in Japanese

• ハイファイCommon
  noun, na-adjectiveThe common word for hi-fi. Use it in ordinary talk about stereo equipment or high-quality sound reproduction — the everyday sense of the English word.
  ロックの場合ばあい、何なんを基準きじゅんにハイファイとするのかが難むずかしいですね。↗

  For rock it's hard to know on what basis you should call something 'hi-fi'.
• 高忠実度こうちゅうじつど
  nounA less common term meaning high fidelity. It is seldom the word you want for everyday hi-fi; it really suits technical writing, where fidelity of sound reproduction is the subject.

For hi-fi in the ordinary sense — stereo equipment, high-quality sound — use 「ハイファイ」, the common word; 高忠実度 is the less common technical term for high fidelity, found in technical writing.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• ハイファイhi-fi
• 高忠実度こうちゅうじつどhigh fidelity