Saturn,
Sorry about the confusion. Yes, there are two places to set the sub level: on the sub and on the receiver. How you set each one doesn't matter so much as what the end product is. For example, setting the subs gain low and the receiver's level high has the same effect as setting the sub's gain high and the receiver's level low. I have my sub set medium low and the receiver's level set high because my SVS sub's auto-of/on signal detect circuit works better this way.
Saint,
Ideally, you want all your speakers and your sub to play a full-spectrum test tones (pink noise) at the same volume. This is where the SPL meter comes in. While it's possible to get speakers calibrated pretty well using just your ears, it's very hard to do a sub this way since our ears are less sensitive to low bass. This is why I suggest you use an SPL meter to achieve the proper balance.
