solderdude
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measureutternutter
Posts: 4,881
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Post by solderdude on Oct 30, 2014 14:45:26 GMT
Hi Pete,
Indeed I am using REW for measurements. I don't have any compensations nor filters in REW though.
My mic pre-amp has the needed correction hardwired in it (bass + 16kHz peak for WM61A) and puts out line level. So all I needed to do was to loop a 'loaded' headphone amp with the line in (SB1240 and lately EMU0204) to create a reference plot and to calibrate SPL. For this I have a (calibrated) SPL meter and a cheap one (these barely differ).
The correcttion needed depends on the mic and coupler type.
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Post by dhruv96 on Apr 10, 2020 9:30:11 GMT
I just want to clarify something
Well, IEC711 standard coupler says something else about M50x and M40x
When you guys say dip in upper mids, that thing I am not able to understand because according to a proper GRAS measurement kit, it actually shows elevation, and a lot of elevation, which makes it shouty and a lot more treble(when compared to Diffuse field and Harman). M40x is tamed whereas M50x shows 3dB more at 3kHz and spiky treble.
So M50x doesnt really have a dip and the old compensation techniques have been proved obsolete because IEC711 raw measurement actually shows how things really sound.
M50x has a dip in 250Hz (sharp dip) which makes bass separate from mids. And it has more uppermids
M40x has bump from 300Hz, and upper mids in line with Harman but is peaky and dippy and not consistent
Well.. One thing I can say about M40x solderdude mod(I actually love it) is that I finalized it with M40x stock foam sheet and 1mm felt at center of driver cutout with shure 940 pads gave amazing result.
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solderdude
Administrator
measureutternutter
Posts: 4,881
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Post by solderdude on Apr 10, 2020 17:04:31 GMT
I measure what comes from the driver and not what a coupler makes from it that is designed to measure DF or FF. Headphones are neither DF nor FF.
I know it has become a 'standard' and that folks need to adhere to that. I don't and as far as I know the measurements I make have a high correlation to how I hear them and not to what certain couplers tell me.
Couplers have various resonances and peaks that provide a similarish (but not exact) load to the driver but do not actually measure what the driver puts out. For that the added peaks and resonances need to be removed again. This is not the same for different headphones but as there is only 1 compensation available there is an error.
My measurements do not have an error that needs correction and thus measures what reaches the ear.
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