Juha

Does Benchmark.exe have write permission for D: root (is D: system drive)? You can test this by running Benchmark.exe" -i ''D:\DPK.wav'' (result file is then "testout.wav" and it is located at path of the directory designated for temporary files) Is the file format of DPK.wav supported by Benchmark.exe (meaning mainly bit depth (IIRC, RAW and 16-bit formats are supported)?

Hmm... as Configuration Editor just writes the updated configuration file(s), delay depends on how much and what kind of stuff you have there in editor side to write to the file(s). If you hand code a simple 1st order LPF in config.txt it would add latency (seen in editor's metering) quite a bit because of extra lines of code (parsing these code lines and executing all coded commands would add latency too but, I think it's not related to the reported latency value because of parsing/calculations...

Hmm... as Configuration Editor just writes the updated configuration file(s), delay depends on how much and what kind of stuff you have there in editor side to write to the file(s). If you hand code a simple 1st order LPF in config.txt it would add latency (seen in editor's metering) quite a bit because of extra lines of code (parsing these code lines and executing all coded commands would add latency too but, I think it's not related to the reported latency value because of parsing/calculations...

If you decide to use IIR filters, remember keep the filter order low (use 1st or 2nd order filters) because of the target of the combined (sum) response of LPF and HPF is flat ( zero phase and zero gain). LR4 and 4th order Butterworth filters seems to result bad sum response when crossover frequency is low (as your 150Hz) and it gets worse with higher sample rates.

I see these enabled (in .vcxproj) <optimization>MaxSpeed</optimization> <intrinsicfunctions>true</intrinsicfunctions> <multiprocessorcompilation>true</multiprocessorcompilation> Dunno what these actually results to in MSVC world (been using only GCC and Clang last few years (in Ubuntu)). With VC++ own tools one could check this. "Directory change notification" runs in its own thread (FilterEngine class, IIRC).

... and now we have to guess the rest with a resolution to your problem? Much more information is needed from your side!

If those screenshots are taken to follow your story then, why default device is changed ? Does this same anomaly (disappearing) happen in system playback devices dialog? If your headphones are BT then, have you tried by - uninstalling APO for those other BT headphones (Configurator) and/or - disabling these devices through system playback devices dialog?

You could try by starting Windows in safe mode. Does Configurator open then ?