Yup. When I had a 2 channel, I preferred the sound from the sub hooked up to line level. Of course, it was probably just my imagination, but it just makes more sense to me to take a line level signal and amplify that than to take an amplified signal, attenuate (is that the right word?) it, and then amplify it. The downside is you'll lose the volume control over the sub, and you'll have to adjust the sub volume at the sub instead of at the receiver.

I am the Doctor, and THIS... is my SPOON!