I have an HK630 and HK3270 which I use with a variety of Axiom speakers. I normally play movies around -10 and music around -20 on the M60s, going down to -20 and -30 respectively for "background" listening.
Having said that, some CDs need to be played up to 10dB louder (ie -10) to be even moderately loud, and need to be at or above 0dB if I want "loud".
With the smaller, less efficient M2s I had to turn the volume control even higher for the same volume levels but I usually stopped before getting to 0dB.
Your volume settings with the DVD sound reasonable but it does seem like the signal from the satellite box is too weak. Whoever told you "it's the speakers" should probably not be trusted for other important things either
One other thing to check; sometimes when setting up channel levels (eg. left surround up 3 dB, center down 2 dB) you end up with most or all of the channel settings being below zero. That's OK but it does make everything play quieter for any given volume control setting. If you do have most or all of the channel settings set in the -ve range, just adjust them all up by the same amount.
