While HypetheSonics’ main headphone database contains measurements of multiple headphones using a single (GRAS RA0045) coupler, this research database exists to assess the couplers themselves. Various IEC standard, 711 clone couplers and newer (non-IEC standard) devices are considered against human-subject measurements using a relatively small number of in-ear monitors.

Important note: ‘MM’ refers to the response recorded from a MEMS microphone installed in the IEM’s eartip. This procedure changes the overall frequency response, which should therefore not be compared with the standard, non-MM measurements. The HTS CE1 in-ear monitor has its own microphone installed in its nozzle and all CE1 measurements shown are made from that built-in microphone.  The purpose of the CE1 is to compare responses from human subjects and current ear simulators.

We gratefully acknowledge the work of the numerous Discord, head-fi and ASR members who contributed to this project.