i am kind of lost with this, are you saying you need one ear cup to be louder than the other?
if so you need mono headphones or headphone that can switch between sterio and mono, i dont understand why you would want this tho, because if you want mono sound use the headphones for the cue channel and only wear one ear cup, i dont use mono sound because it has a problem in the sence that nearly everything in the body has a dominate feature
eample right handed or left handed
right eye or left eye dominate (only time that i know of to be important is firearms training)
even your legs have a more dominate leg,
i know it all sounds stupid but your ears are no different, you will have one stronger than the other so using sterio sound is much better, and if it is too loud there is a volume control for the headphones, i may have misunderstood the problem and you mean something totally different if so try and explain exactly what it is you are hoping to achive
i may have misunderstood tho