Voom has stated previously that they are aware that some satellite sources have lower volume than others, and that they will do nothing about it - they only pass on the signal they get. They could certainly boost the volume, but if there is any distortion then they get blamed. Also - if they boost the volume and then later the source provider increases it, then we'll be complaining about too high of volume. Sounds like Dish and DirecTV just go ahead and correct it.
This is still a worthwhile exercise because hopefully Voom will either do something about it, or will pass complaints on to the source providers. But - I doubt that the source providers will do anything since they have to worry about impacting all of their customers. In the case Voom originated programming, there is no reason for them not to correct it.