[LAU] Ardour: delay in audio when recording

Hello, I have some synth tracks recorded. Now I want to record some acoustic bass. So I set Ardour's option to monitor using Ardour and I put on headphones so the mic will only pick up the acoustic bass. Problem is, there is a slight annoying delay between the sound I hear from the bass itself and the sound relayed in the headphones. Machine is x86_64 and system is Fedora 15. Kernel is from Fedora. Maybe monitoring using hardware (the first option) might give better, delay-free results. How can this be set up when the system has an M-Audio 1010LT card and a pair of M-Audio speakers connected as system 1 and 2 outputs ? Any suggestions/hints about how to monitor acoustic instruments would be very much appreciated. For the time being I play the recorded tracks through the speakers at very low volume while recording the acoustic bass but the speaker sounds leaks into the mic - not so good at all, but gets things done. Cheers.