[OPEN] Pioneer SDJ05 Speakers Quiet and Distorted

I just received a brand new pair of SDJ05s in the mail, and I connected the link cable from the first one's Out to the second one's In, plugging the volume control into the first one's In, and I used a 3.5mm TRS auxiliary cable with a 3.5mm->6.35mm TRS adapter, and the audio I get from them is insanely quiet. When it's audible, the sound is noticeably distorted and muddled, particularly with highs and lows.

These are brand new. Am I doing something wrong or do I need to look into Amazon's return policy?