1. Do a sub crawl.
- Place the sub in your listening position, at roughly ear-level (when seated).
- Play test tones or some content with deep bass.
- Crawl around the room and find the locations where bass is most pronounced.
- Place your sub in one of those locations.
2. Run Audyssey.
i) Set the gain on the sub itself to "noon" to start.
ii) Run the first cycle of Audyssey (all 6-8 positions).
iii) Save the result and check the levels in the AVR's speaker set-up menu.
iv) If the level of the sub:
- is within a few dB of the levels of the other speakers, you're fine;
- is too low, lower the gain on the sub;
- is too high, raise the gain on the sub.
v) re-run ii) to iv) as necessary.
(See this post for more information: WELCOME TO THE AUDYSSEY MULTEQ FAQ AND 'AUDYSSEY 101'!
3. Tweak if / as desired or required.