A portable rig for measurements on the go

Discussion in 'IEM Measurements - La Cenric's IEM Playhouse' started by La Cenric, Dec 25, 2016.

  1. macro

    macro Rando

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    Sweet! Thank you. I will run those through my program tonight or sometime this weekend and report back, although I'm not sure which SE846 filter @La Cenric measured.

    I'm not sure I'm following you. Are you suggesting that we not use any sort of smoothing on the compensation curve and that La Cenric should be controlling for insertion depth by aligning the resonant peaks and troughs in the treble frequencies when performing these measurements?
     
    Last edited: Oct 19, 2017
  2. briskly

    briskly Friend

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    SE846 description says blue filter.

    -I don't like any more than minimal smoothing. I find it conceals the sound character.
    -I think alignment is necessary only if the goal is to compare the result to a result on another coupler. As far as general measurement goes, whatever seems a realistic depth given the tips and earpiece.
     
  3. La Cenric

    La Cenric Friend

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    Again, I only really need an approximation. The frequencies above 7k is highly reliant on insert depth which is why I requested for said arbitrary flattening since not enough information to determine a proper compensation curve that disregards variation in peak placement.

    That said, if I do correct for the proper insert depth and normalises the resonant peak at the exact same level for both the IEC60318-4 microphone and the Dayton IMM-6 + tubing, I get the following compensation (special thanks to @bartzky for the help for this):

    compcurve2.png

    Which, as stated before, doesn't directly apply to the measurements performed with the iOS app for some reason.

    Also, the fact that Tyll and I use different insert depths really hinder trying to calibrate the IMM6 measurements to Innerfidelity's standard. Resonant peaks are in different places so it's much easier to make a blanket solution of flattening the compensation in the top end.
     
  4. bartzky

    bartzky Acquaintance

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    @macro great work!
    Do you mind sharing some data? E.g. some Excel sheets or txts with frequency and gain values?

    Regarding the arbitrary flattening I have to agree with Cenric. Of course it's compelling to aim for an exact fit across all frequencies. But the deviations in the high frequency range are just to big to get a proper calibration curve. Furthermore even IEC 60318-4 spec'd gear is only accurate to 10 kHz.
     

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