There is no reason why the volume level when playing a DVD should be exactly the same as other sources. For one thing, the volume level will depend on how the disc was recorded. A disc might be recoreded "softly" so as to leave room (with the available number of bits) for loud dynamic peaks. Conversely, a disc might be recorded "loud" for improved resolution of quiet passages, but this would require greater limiting of the peaks.
Don't worry about turning up the volume. What you really are doing is attenuating the signal less. Ideally, the volume control would be all the way up, and/or removed entirely from the circuit.
Don't worry about turning up the volume. What you really are doing is attenuating the signal less. Ideally, the volume control would be all the way up, and/or removed entirely from the circuit.