History Channel and Sub woofers?

I have a 2.1 audio system and ONLY on the History Channel, the subwoofer cuts out every couple of minutes for several seconds.  This is most notible on the Ancient Aliens show.  I watch a few dozen channels plus Netflix and BluRay discs and the sub never cuts out with any of those.  I directly connected my speaker system to the Verizon box with an analog audio cable and then an optical audio cable.  Same result.  Why would this happen on one channel and does it happen with anyone else?  Could I have a bad TV box?