an overly-researched response to https://www.youtube.com/watch?v=ZwPLhyUgm-g Ad read sponsored by https://shenzhenaudio.com/ ⇊ Come look at my own graph database ⇊ 1,000+ IEMs measured: https://crinacle.com/graphs/iems 200+ headphones measured: https://crinacle.com/graphs/headphones IEM Graph Comparison Tool: https://crinacle.com/graphs/iems/graphtool Headphone Graph Comparison Tool: https://crinacle.com/graphs/headphones/graphtool PATREON: https://patreon.com/crinacle TWITTER: https://twitter.com/crinacle DISCORD: https://discord.gg/crinacle SUBREDDIT: https://reddit.com/r/inearfidelity MERCH: https://merch.crinacle.com/ 00:00 Intro 01:55 Context 02:10 TL;DR 02:44 How do measuring rigs work 03:08 Head simulations 03:32 Ear canal simulators 03:40 2cc coupler 05:14 Zwislocki coupler 05:51 IEC60711 "711" coupler 06:01 IEC60318-4 (also "711") coupler 06:27 GRAS RA040X 07:00 Head and Torso Simulator (HATS) 03:40 The Big Three 07:53 GRAS KEMAR 08:38 B&K/Head Acoustics 08:51 ITU-T Type 3.3 pinna 09:16 The New Generation 09:28 Why "711" might be wrong 09:52 B&K Type 4620/5128 10:32 Head Acoustics HMS II.3 LN HEC 11:09 LTTLab's final decision 11:29 Type 5128 vs HMS II.3 LN HEC 11:47 Why use a GRAS KEMAR instead 12:15 Cheaper alternatives? 12:27 711 couplers 12:47 2cc couplers 12:55 GRAS 45CA/43AG 13:06 DIY flatplate system 13:22 MiniDSP EARS 13:39 Binaural recording setups 13:52 Chinese clones 14:37 Why so expensive? 15:30 Caveats and warnings 15:35 Distortion graphs 16:02 Time domain stuff 16:27 Actively update the database 17:17 Sound demos (For the true nerds, please mentally swap any mention of "inner ear simulator" to "occluded ear simulator" because I'm a fraud that got terms mixed up) CAMERA: Sony a7S III + FE 35mm f/1.8 MICROPHONE: Motu M2 interface + Neumann TLM 102 SPEAKERS: Neumann KH120 + KH750 MONITOR: LG C1 48" OLED ~ CITATIONS ~ Sachs, R. M., & Burkhard, M. D. (1972). Insert earphone pressure response in real ears and couplers. The Journal of the Acoustical Society of America, 52(1A), 183-183. Burkhard, M. D., & Sachs, R. M. (1975). Anthropometric manikin for acoustic research. The Journal of the Acoustical Society of America, 58(1), 214-222. Larson, V. D., Studebaker, G. A., & Cox, R. M. (1977). Sound levels in a 2-cc cavity, a Zwislocki coupler, and occluded ear canals. J. Am. Aud. Soc, 3, 63-70. Snaidero, T., Jacobsen, F., & Buchholz, J. (2011). Measuring HRTFs of Brüel & Kjær Type 4128-C, GRAS KEMAR Type 45BM, and Head Acoustics HMS II. 3 Head and Torso Simulators. Lyngby, Denmark: Technical University of Denmark, Department of Electrical Engineering. Jønsson, S., Schuhmacher, A., & Jørgensen, H. I. (2018). Wideband impedance measurement in the human ear canal; In vivo study on 32 subjects. arXiv preprint arXiv:1811.03389. IEC 60318-5:2006 IEC 60711:1981 IEC 60318-4:2010 IEC TR 60595:1990 IEC 60318-7:2022 Recommendation ITU-T P.57 (06/21) Recommendation ITU-T P.58 (06/21)