Minimizing audio output lag
In Windows10, in many cases, you can reduce the sound output delays by applying Microsoft High Definition Audio Driver.
(I think 3rd-party sound driver should also support the low latency. However, I think currently (August 2019) only Microsoft's driver support it)
If you are interested in it, follow the steps below to update the sound driver to the Microsoft's low-latency driver. That driver does not have the hardware dependency. So the driver can apply to any audio hardwares.
# I don't recommend to apply the driver if "you're not familiar to update the driver manually" or "you cannot recover the driver to the last one".
After these settings, start DTXMania again. The buffer size of WASAPI(Exclusive or Shared) become smaller (or you could set the smaller value of the buffer).