What is the exact type of jack on your PC, a stereo TRS (Tip/Ring/Sleeve) audio output only, or a combined audio out/mic in TRRS (Tip/Ring/Ring/Sleeve)?
Usually, the issue is if you use the remote/mic TRRS cable plugged into an audio out only TRS jack. Some of those jacks do not have a very solid ground tab (are not in spec). The pinout of the TRRS is Left (T)/Right (R)/Ground (R)/Mic(S). What should happen if you plug in a TRRS to a TRS jack, is the ground tab of the jack should contact both the ground and mic contacts of the plug, the RS of the TRRS plug. What happens when you push it all the way into a crappy TRS jack is the ground tab only contacts the mic (S), leaving the headphones ungrounded which causes them to sound exactly as you describe (no bass, very distant sounding). When you push the mic button, it shorts the mic/ground lines (normally how a phone detects the button press), which grounds the headphones and they'll sound normal. When you pull the plug out just a little, the ground tab now contacts both the ground/mic pins, grounding the headphones, causing them to sound normal.
The L1's are fine. The jack on your pc doesn't work right with the remote/mic cable.
1) use the non-mic cable on your pc
2) get a better pc/sound card with better 3.5mm jacks
3) get a TRRS jack to separate headphone/mic plugs to use the mic on a PC. (looks like a female 3.5mm to dual male 3.5mm, but has a female TRRS to dual male TRS jacks, one for headphones, one for mic)