In-Ear Fidelity

IEF Headphone Graph Database: Public Release

A beauty.

Sorry for the radio silence the past week or so, I’ve been busy doing… well, this.

100+ headphones has been added to the “official” IEF headphones graph database, and with that number I am now comfortable enough to push it as a public release. Some further details:

  • Each dataset is obtained from both left and right channels so as to get better averages and also provide insight on channel matching consistency.
  • Each channel is an average of 3 placements, for a total of 6 data points per set.
  • Placements are done so in as “natural” positions as possible. Odd positions are not forced, getting different measurements for the sake of different measurements seems rather counterintuitive.
  • Placements are also selected according to seal. Compromised seal data points are omitted from the data set, and the “best 3” are selected.

As you can see from the above picture, the Graph Comparison Tool (for headphones) is also up. For now, it allows for unlimited comparison points as well as the ability of overlay the following target curves:

  • Proprietary “IEF Neutral” target
  • GRAS KEMAR-specific Diffuse Field response
  • GRAS KEMAR-specific Free Field response
  • Harman In-room flat (which is derived with a GRAS KEMAR)
  • Harman AE/OE 2018 target

Full functionality will be up till November. After that, all public users will only be able to compare up to 2 entries, though everyone will still be able to select the “IEF Neutral” target for overlay. The other target curves will only be available to premium subscribers, as will the ability to compare unlimited entries.

The following headphones have been added to the database:

Obligatory credits section.

GRAS 43AG-7 partly funded by:
Riveton Headphones & Goldvein Cables
Super* Review
Prisma Audio

Special thanks to >$50 contributors:

Jon Bokic
Alan Lin
Robert Taylor
Tareq Abou Samra
Denis Dmitriev
Jonathan Pelchat
Random Bot
Desert Scrub
oSeven brother
Joe Curcio
Daniel Thomas
Jakob Tsang
Jay Yang
Teddy Ong
Ian Maddela
Michael Giardina
Hardeep Singh
Michael George
Edward Yap
James Nguyen

Support me on Patreon to get access to tentative ranks, the exclusive “Clubhouse” Discord server and/or access to the Premium Graph Comparison Tool! With current efforts to measure more headphones, those in the exclusive Patreon Discord server get to see those measurements first before anybody else.

My usual thanks to all my current supporters and shoutouts to my big money boys:

Man Ho

5 thoughts on “IEF Headphone Graph Database: Public Release”

  1. Fantastic work as always. Pretty sure it’s gonna turn into the defacto headphone comparison tool, like your iem one!

    One question though. I’m just going through the headphone graph comparison tool.
    And found that the target curves (IEF and Harman) in legacy comp. have peaks around 6k & 9k, while the GRAS one doesn’t. Any specific reason for that?

    1. The legacy rig (EARS + 711) does not conform to any industry standard. Additional calibration is required for its data to be used with Harman research, which is done on a GRAS KEMAR. As such, the IEF Neutral target on the legacy rig will be different from the target on the new GRAS 43AG-7 rig mainly due to the different pinna (and to certain extent, the occluded-ear coupler) used.

  2. Well, outstanding! I finally have pictures of how my headphones sound! This helps immensely.

    My casual, walking-around headphones are the B&O H7, and I am wondering: are those graphs wired or wireless?

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