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Some measurements of IDT 92HD93 headset out in Dell Latitude E6330

AnalogSteph

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I've been meaning to do this forever now.

While the combo of Focusrite Forte and RMAA (both a bit flaky) was subjectively causing grey hair to sprout at an alarming rate at first, things ultimately went reasonably smoothly. Signal chain:
Battery-powered Latitude E6330 (w/ Win10 22H2, Win 7/8.1 driver as supplied by Dell, MME) headset out --> TRS --> 2x XLRm (Sommer Cable Basic HBA-3SM2-0150) --> 2x XLRf --> TRS (Cordial CFM 0.6 FV) --> Focusrite Forte Line-In (+3 dB in input gain gives a calibration level of -1.0 to -1.4 dB at full output depending on sample rate, or +9 dB at output 67 = -6 dB; this points to a maximum output level of about +5 dBu or 1.4ish V)

E6330-rmaa-summary.png

Full set of results

The most shocking part of all this is that I found precious little to be glaringly wrong. There is almost as much dynamic range as you could ever want for a line-level source, even if with the usual rise in noise towards the low end as typical for consumer sound chips, and the noise floor rises by a moderate ~3 dB in THD vs. DR tests. Distortion is low at 1 kHz even if IMD does degrade towards the treble, again nothing unusual. (Estimated THD+N about -90 dB at 1 kHz.) Playback speed appears to be accurate to within 25 ppm (0.0025%). Periodic filter ripple is nothing much to write home about at about +/- 0.05 dB with roughly a 6 kHz period (Julian Dunn would not be proud), but even that is nothing I would call terrible. Is that really enough for my ears to complain that the treble ain't right?

44.1 kHz plain vanilla:
E6330-44k-fr.png


Same if upsampled to 192 kHz via Windows audio stack (Windows audio stack resampling has come a long way...):
E6330-44k@192k-fr.png

She's a beaut! :D

The difference:
E6330-44k-filter-ripple-subtract44k@192k.png


48 kHz plain vanilla:
E6330-48k-fr.png


48k upsampled to 192k:
E6330-48k@192k-fr.png


The difference at 48 kHz:
E6330-48k-filter-ripple-subtract48k@192k.png


(And yes, I subtracted both 44.1 and 48 kHz graphs in the same order, so yes, the difference is real!)

The designers clearly did not give a hoot about hi-res audio for bats, with filters becoming increasingly relaxed until 192 kHz looks like this:
E6330-192k-fr.png


So this is not the one to use with software stereo MPX for your pirate FM radio station - not like anyone would, mind you...
 
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