[WriteLog] Where to grab headphone audio?

[Napa]

I have a Heil Proset and I have the Mic plugged into the Mic input on the
sound card but where should I grab audio for the headphones. I tried the
Line out using a "y" with the line out cable from the interface but it
sounds like crap using the computer speakers and it's only in one speaker
(headset included). During RTTY tests I do not usually use the headset just
a speaker in front of me between the monitors. I tried lowering the audio
level going to the speakers using the Writelog sound mixer but when I get it
low enough to get rid of the distortion I loose RX sensitivity. I'm using a
KW TS-940 and a PCI128 card.

Any thoughts ?

Randy N1KWF