Newbie question about volume
Hey guys, I'm kind of new at this home theater busineess and I had a question about volume. First a little background.
I have a Denon AVR-1905, 2 Polk Rti-4 front speakers, and a Polk PSW 10 sub. I plan on adding a center channel and surround speakers later. My question is this: When watching regular TV or listening to music I usually set the volume on around -35. However, when I watch a DVD movie, I have to set the volume up to around -20 to -15 to really hear, especially the dialogue. Is this just because I don't have a center channel speaker? I did the setup through the receiver and it knows I don't have a center channel speaker. Shouldn't it route all the dialogue through the front speakers? Sorry for the newbie question. I'm sure this is obvious to most of you guys. I would really appreciate some help. Thanks.