true Neptunes have these built into the door.....
for the most it must work, why else would they be put there.....extra expense for no reason?.....might as well toss an old sneaker inside the cabinet as well, serving no purpose, except maybe absorbing noise...
consider them noise cancelling headphones!...for the most part, thats what they do, cancel out noise....
is it LIVE, or is it Memorex?