Direct Sound Selection.
On a system with more than one sound device TimeDX must be told which sound card is to be used for
audio output testing purposes. This selection will determine which sound card DMDX uses
Of interest here is that there can be several drivers for the same sound card, usually there is one called the Primary sound device, then there may be one or two more, both mapped to the same device. The capabilities of these devices seems to differ a bit, on one of my machines there is an emulated mode that does not work very well at all whereas the other devices listed function correctly -- so some care and or experimentation is required here to find out which device functions the best. In the past emulated drivers never worked very well at all (see the Sound Latency test), lately some of them seem to function as well as non-emulated drivers.
Another thing I've noticed here is that if the sound drivers are poor having another application open or previously active that uses sound can cause the playback to be poor, a detail noticeable with DirectX games as well. By poor I mean little glitches in the sound that is a synchronization error between the buffers and the hardware. Upon checking the hardware settings for this machine I found that the drivers were generic MS Windows Sound System Compatible drivers and not the Crystal 4232 that I knew was in the machine, I found the correct drivers and installed them and now the playback is beautiful. Well, it sounds good but the synchronization is shoddy with this particular card as it is still an emulated driver.