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Etymotic Research ER-4S measurement

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speakerphone:























I didn't uploaded CSD and Distortions of right channel. Because both channels are almost the same.


My artificial Ear (Coupler) follows IEC 60318-4 (former IEC 60711), ITU-T Recommendation P.57, ANSI S3.25 standards.​


About the measuring standards

I mostly follow the IEC 60268-7 standard. I use O2 Amp for Lower the output impedance close to 0ohm. (In IEC standard, amplifier output impedance should be 120ohm.)
Also I use [1/24 octave smoothed Pink periodic noise] for frequency response analysis, and [1/6 octave stepped sine] for harmonic distortion analysis.
 
 Diffuse Field Compensation Target follows the ISO 11904-2 standard, and Olive-Welti Target follows latest In-Room research. (Olive, Sean; Welti, Todd; McMullin, Elisabeth at AES).
But, as we know, frequency range of ISO 11904-2 standard is 20~10000Hz. So I dealt [-6dB/Oct.] at 10000Hz~20000Hz.




References

IEC 60318-4 : Electroacoustics - Simulators of human head and ear - Part 4: Occluded-ear simulator for the measurement of earphones coupled to the ear by means of ear inserts
http://webstore.iec.ch/webstore/webstore.nsf/artnum/043703!opendocument

ITU-T Rec. P.57 : Series P: Telephone transmission quality, Objective measuring apparatus : Artificial ears
http://www.itu.int/rec/T-REC-P.57

​​ANSI/ASA S3.25 : Occluded Ear Simulator
http://webstore.ansi.org/FindStandards.aspx?SearchString=s3.25&SearchOption=0&PageNum=0&SearchTermsArray=null%7cs3.25%7cnull

IEC 60268-7 : Corrigendum 1- Sound system equipment - Part 7: Headphones and earphones
http://webstore.iec.ch/webstore/webstore.nsf/artnum/043714!opendocument

ISO 11904-2 : Determination of sound immission from sound sources placed close to the ear
http://www.iso.org/iso/catalogue_detail.htm?csnumber=32439

​Olive-Welti Target : Listener Preferences for In-Room Loudspeaker and Headphone Target Responses
http://www.aes.org/e-lib/browse.cfm?elib=17042



Feel free to ask a question about this!
But I'm not native English speaker, so I'm not very good at English.

And anyone who knows how to use 'attachment'? I don't know how to, so I'm using my blog http to upload a file.

shotgunshane:
Thanks for the measurements. I would say I relate to the ER-4S measurements for diffuse filed compensation for frequencies 5k and above, and relate more to the Olive-Welti compensation for everything below 5k.

briskly:
Looks pretty typical of the ER-4S into the 60711. I find my taste closer to the conventional diffuse field here.
I don't know what IEC 60268-7 specifies for measurement level and reference frequency, can you describe it in detail?

speakerphone:

--- Quote from: briskly on February 09, 2015, 07:52:55 PM ---Looks pretty typical of the ER-4S into the 60711. I find my taste closer to the conventional diffuse field here.
I don't know what IEC 60268-7 specifies for measurement level and reference frequency, can you describe it in detail?

--- End quote ---

IEC (International Electronical Committee) 60268-7 is international standard about way of measuring Headphones and earphones.
That specified article about HATS(coupler) as a frequency response, measuring impedance, harmonic distortions and so on.

Reference frequency in standard is 94dB @ 500Hz or 1mW output for that headphone. I'm using 94dB @ 500Hz.

And In standard, only thing that we could trust in harmonic distortion is just THD, 2nd, 3rd harmonic.

And according to IEC 60318-4, my coupler's reliable frequency range is ~16kHz.
So 16kHz~20kHz is not that accurate.

OJneg:
Cool to know someone has a real IEM coupler. +1 for you

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