Audio lantency with Alsa

Dear JB and friends,

When installing MLT from Debian Marilat or compiling SVN directly,
it seems that audio latency is not the same. Why ?

Would it be possible to specify the audio latency in Kdenlive settings, to drive latency to a minimum?
For accurate audio editing, low audio latency is needed.

Any comments are welcome.

Kind regards,
Jean-Michel