Signal quality of Mono Sub output

[Antoine]

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OK. I've just reinstalled REW and made some measurements. I am sorry, but I can't reproduce the issue. Both type of configs measure identical. I've measured from 0-200Hz.

It is strange however that the infoscreens on the Devialet show a 'stereo preout installed' whether I use a mono configured pre-out or a stereo pre-out. If I am not mistaken a mono pre-out was displayed in the past.

I do however notice differences in the dp_cfg.txt configuration files. Differences I would expect. (NB. Be careful: you seem to need to clear the browser cache between the downloads or identical configs are saved!!)

Signal processing
Mono: "MUTE":5, Stereo: "MUTE":7

COAX1:
mono: "TYPE":"INPUT_NOT_AVAILABLE"
stereo: "TYPE":"ANALOG_OUT"

COAX2:
mono: "_dac_mix":"mono"
stereo: "_dac_mix":"right"

Pre-out:
Mono: "usedAsGroup":false
"usage":[{"direction":"output","type":"Sub","defaultName":"Digital 2"}]
Stereo: "usedAsGroup":true
"usage":[{"direction":"output","type":"Preout","defaultName":"Preout"},{"direction":"output","type":"Preout","defaultName":"Preout"}]

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Results of the measurements in the picture attached. I haven't taken great care in calibrating the SPL output (battery of SPL meter empty) or mic placement but this does not matter as the goal was to compare. In between measurements nothing changed in the measuring setup. Measurements show the combined output of sub+fronts.

The purple graph is the Anti-Mode in bypass.

The two graphs with red are both made with the infrasonic filter disabled.

The other graphs all with the infrasonic filter enabled and using either a stereo pre-out or mono pre-out.


edit: seeing that the infrasonic filter on the Anti-Mode is not needed/detrimental I'll keep that disabled from now!