Traktor s4 mk2

Hey guys.

So I was djing at a party last night using my s4, and the sound system was just a stereo with 2 basic speakers. Nothing fancy just something you'd find in a garage or somethinget. Anyways near the end of the night the low end of the music cut out there was no bass and I smelled burning plastic. Obviously I dunplugged everything and packed it up. The speakers didn't sound right through an aux cable input either (standard rca to headphone jack). Got home today and through a 1/4in adapter I tried to mix on these small little logitech speakers and again no bass. When I route the audio through my pc sound card to the speakers in traktor there's more than enough bass and same if I just connected my phone to the speakers to play music. When connecting my headphones to the 1/4in out there was bass, also in the headphone jack for the cue there was low end as well.

Nothing was spilled on the mixer at all, though near the power bar there was some sticky residue (not sure if someone spilled pop or beer) and there were a few wet spots on the adapter. Other than the no low end there's nothing wrong, all buttons,faders sliders knows etc. Work. I'm worried the sound card blew and I don't have any other speakers to test it out on at the moment so I'm worried.

If I'm getting bass through the headphones as the main out and through cue there shouldn't be any internal damage correct? Speakers too weak to support the s4 or am I sol?

Many thanks in advsnce ,

Awisko