If you're interested enough, put the other cable back on to make sure. Take a measurement with both cables, see what the difference is in real numbers. "Too much" isn’t telling us much. Is it an extra 3dB? 6dB? At what frequencies? I noticed a sound difference with two different amps on the same speakers. I was totally surprised to perceive the difference so I took sweeps with both amps, speaker and mic. in the same position, and volume adjusted. Sure enough, the two amps caused a different frequency response. What surprised me even more was that the difference wasn’t what I was expecting. The amp I suspected of having rolled off high frequencies actually had more output above 7k. It had slightly less in the range between about 2K and 7K, and I was perceiving that as "rolled off" highs.
I think one reason us measurement people get caught up in accusing the "subjective" camp of imagining things is that we jump to conclusions that they are claiming to hear things that are far below the threshold of human perception because we assume that their equipment is all operating to some theoretical test bench standard when it in fact may not be. I think that often if a direct measurement of the sound off their speakers is made before and after an equipment change that caused a perceived change in sound quality, a difference will show up that is known to be in the audible range.