Do you want exact initial time delay?

If WinMLS is not in loop-back mode (See the ‘Measure initial time delay?’ drop-down list in Measurement->Sound Card Settings...), note that the initial time delay of the sound card varies with one sample (for the VXpocket 440 card it varies much more). This means that if you want the exact same initial time delay from one measurement to another you should make sure WinMLS is in loop-back mode (it uses channel two for synchronization).